Overview

Dataset statistics

Number of variables9
Number of observations56
Missing cells0
Missing cells (%)0.0%
Duplicate rows0
Duplicate rows (%)0.0%
Total size in memory4.1 KiB
Average record size in memory74.4 B

Variable types

Text5
Categorical4

Dataset

Description한국원자력연구원 데이터 입니다. 데이터 칼럼 리스트는 저자, 소속, 논문구분, 제목, 출판년도, 페이지 수, 언어, 키워드, 초록 입니다. (국내 원자력공학 및 에너지공학 관련학과의 석박사논문으로서 KAIST, 서울대학교, 한양대학교, 제주대학교 등이 해당되며, 석박사논문의 특징은 과학 지식발전에 독창적으로 기여하며, 해당 학문분야의 기준이 되며, 지식 사회에서 지속적인 가치가 있을 내용이 수록되어야 하며 연구의 목적과 연구를 통해서 풀고자 하는 문제 등을 충분한 문헌고찰을 통해서 명학하고 합리적으로 서술되어 있으며, 연구결과의 단순한 반복제시가 아니라 연구결과가 지니는 의의의 중요성 등을 전체적 맥락에서 타당한 과정을 통해 논리적으로, 객관적으로 해석하여 결론을 유도하도록 되어 있으며, 대부분 상업적인 경로로는 입수하기 어려움이 있음
Author한국원자력연구원
URLhttps://www.data.go.kr/data/15012505/fileData.do

Alerts

소속 has constant value ""Constant
언어 has constant value ""Constant
저자 has unique valuesUnique
제목 has unique valuesUnique
키워드 has unique valuesUnique
초록 has unique valuesUnique

Reproduction

Analysis started2023-12-12 07:01:02.204856
Analysis finished2023-12-12 07:01:02.716719
Duration0.51 seconds
Software versionydata-profiling vv4.5.1
Download configurationconfig.json

Variables

저자
Text

UNIQUE 

Distinct56
Distinct (%)100.0%
Missing0
Missing (%)0.0%
Memory size580.0 B
2023-12-12T16:01:02.895646image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Length

Max length17
Median length16
Mean length13.678571
Min length11

Characters and Unicode

Total characters766
Distinct characters36
Distinct categories4 ?
Distinct scripts2 ?
Distinct blocks1 ?
The Unicode Standard assigns character properties to each code point, which can be used to analyse textual variables.

Unique

Unique56 ?
Unique (%)100.0%

Sample

1st rowSohn, Se Do
2nd rowTrinh, Huu Toan
3rd rowLee, Hyeok Moo
4th rowKim, Jong Woon
5th rowChi, Yong Ki
ValueCountFrequency (%)
lee 12
 
7.1%
kim 11
 
6.5%
seung 4
 
2.4%
jong 4
 
2.4%
hyun 4
 
2.4%
han 4
 
2.4%
chang 4
 
2.4%
soo 4
 
2.4%
sang 4
 
2.4%
kwang 3
 
1.8%
Other values (84) 114
67.9%
2023-12-12T16:01:03.240350image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Most occurring characters

ValueCountFrequency (%)
112
14.6%
n 83
 
10.8%
o 79
 
10.3%
, 56
 
7.3%
e 52
 
6.8%
g 48
 
6.3%
u 39
 
5.1%
S 32
 
4.2%
a 30
 
3.9%
K 25
 
3.3%
Other values (26) 210
27.4%

Most occurring categories

ValueCountFrequency (%)
Lowercase Letter 431
56.3%
Uppercase Letter 167
 
21.8%
Space Separator 112
 
14.6%
Other Punctuation 56
 
7.3%

Most frequent character per category

Uppercase Letter
ValueCountFrequency (%)
S 32
19.2%
K 25
15.0%
H 20
12.0%
J 18
10.8%
C 13
7.8%
L 12
 
7.2%
Y 10
 
6.0%
D 7
 
4.2%
G 7
 
4.2%
W 5
 
3.0%
Other values (9) 18
10.8%
Lowercase Letter
ValueCountFrequency (%)
n 83
19.3%
o 79
18.3%
e 52
12.1%
g 48
11.1%
u 39
9.0%
a 30
 
7.0%
i 25
 
5.8%
h 21
 
4.9%
y 17
 
3.9%
m 15
 
3.5%
Other values (5) 22
 
5.1%
Space Separator
ValueCountFrequency (%)
112
100.0%
Other Punctuation
ValueCountFrequency (%)
, 56
100.0%

Most occurring scripts

ValueCountFrequency (%)
Latin 598
78.1%
Common 168
 
21.9%

Most frequent character per script

Latin
ValueCountFrequency (%)
n 83
13.9%
o 79
13.2%
e 52
 
8.7%
g 48
 
8.0%
u 39
 
6.5%
S 32
 
5.4%
a 30
 
5.0%
K 25
 
4.2%
i 25
 
4.2%
h 21
 
3.5%
Other values (24) 164
27.4%
Common
ValueCountFrequency (%)
112
66.7%
, 56
33.3%

Most occurring blocks

ValueCountFrequency (%)
ASCII 766
100.0%

Most frequent character per block

ASCII
ValueCountFrequency (%)
112
14.6%
n 83
 
10.8%
o 79
 
10.3%
, 56
 
7.3%
e 52
 
6.8%
g 48
 
6.3%
u 39
 
5.1%
S 32
 
4.2%
a 30
 
3.9%
K 25
 
3.3%
Other values (26) 210
27.4%

소속
Categorical

CONSTANT 

Distinct1
Distinct (%)1.8%
Missing0
Missing (%)0.0%
Memory size580.0 B
Korea Advanced Institute of Science and Technology, Daejeon (KR)
56 

Length

Max length64
Median length64
Mean length64
Min length64

Unique

Unique0 ?
Unique (%)0.0%

Sample

1st rowKorea Advanced Institute of Science and Technology, Daejeon (KR)
2nd rowKorea Advanced Institute of Science and Technology, Daejeon (KR)
3rd rowKorea Advanced Institute of Science and Technology, Daejeon (KR)
4th rowKorea Advanced Institute of Science and Technology, Daejeon (KR)
5th rowKorea Advanced Institute of Science and Technology, Daejeon (KR)

Common Values

ValueCountFrequency (%)
Korea Advanced Institute of Science and Technology, Daejeon (KR) 56
100.0%

Length

2023-12-12T16:01:03.362289image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
Histogram of lengths of the category

Common Values (Plot)

2023-12-12T16:01:03.438877image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
ValueCountFrequency (%)
korea 56
11.1%
advanced 56
11.1%
institute 56
11.1%
of 56
11.1%
science 56
11.1%
and 56
11.1%
technology 56
11.1%
daejeon 56
11.1%
kr 56
11.1%

논문구분
Categorical

Distinct2
Distinct (%)3.6%
Missing0
Missing (%)0.0%
Memory size580.0 B
Thesis (Mr. Eng.)
32 
Thesis (Dr. Eng.)
24 

Length

Max length17
Median length17
Mean length17
Min length17

Unique

Unique0 ?
Unique (%)0.0%

Sample

1st rowThesis (Dr. Eng.)
2nd rowThesis (Mr. Eng.)
3rd rowThesis (Mr. Eng.)
4th rowThesis (Mr. Eng.)
5th rowThesis (Mr. Eng.)

Common Values

ValueCountFrequency (%)
Thesis (Mr. Eng.) 32
57.1%
Thesis (Dr. Eng.) 24
42.9%

Length

2023-12-12T16:01:03.519253image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
Histogram of lengths of the category

Common Values (Plot)

2023-12-12T16:01:03.594044image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
ValueCountFrequency (%)
thesis 56
33.3%
eng 56
33.3%
mr 32
19.0%
dr 24
14.3%

제목
Text

UNIQUE 

Distinct56
Distinct (%)100.0%
Missing0
Missing (%)0.0%
Memory size580.0 B
2023-12-12T16:01:03.792903image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Length

Max length167
Median length106.5
Mean length93.589286
Min length54

Characters and Unicode

Total characters5241
Distinct characters63
Distinct categories7 ?
Distinct scripts2 ?
Distinct blocks1 ?
The Unicode Standard assigns character properties to each code point, which can be used to analyse textual variables.

Unique

Unique56 ?
Unique (%)100.0%

Sample

1st rowQuantitative evaluation of software testability for specification in statechart and for source code
2nd rowA modified Lagrangian puff model for pollutant dispersion in complex terrain
3rd rowBlue and white light emission from electron irradiated polystyrene
4th rowGeneration of isotropic and anisotropic scattering cross section for Boltzmann-Fokker-planck equation via extrapolation exponential function and minimized RMS errors
5th rowDesign of compact gamma imager based on pixellated crystal array with high resolution
ValueCountFrequency (%)
of 51
 
6.9%
for 25
 
3.4%
a 25
 
3.4%
and 24
 
3.2%
on 22
 
3.0%
in 20
 
2.7%
the 19
 
2.6%
study 13
 
1.8%
analysis 10
 
1.3%
development 8
 
1.1%
Other values (357) 524
70.7%
2023-12-12T16:01:04.159575image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Most occurring characters

ValueCountFrequency (%)
685
13.1%
e 467
 
8.9%
o 387
 
7.4%
t 383
 
7.3%
a 367
 
7.0%
n 367
 
7.0%
i 353
 
6.7%
r 304
 
5.8%
s 245
 
4.7%
l 201
 
3.8%
Other values (53) 1482
28.3%

Most occurring categories

ValueCountFrequency (%)
Lowercase Letter 4353
83.1%
Space Separator 685
 
13.1%
Uppercase Letter 159
 
3.0%
Dash Punctuation 24
 
0.5%
Decimal Number 9
 
0.2%
Other Punctuation 8
 
0.2%
Connector Punctuation 3
 
0.1%

Most frequent character per category

Lowercase Letter
ValueCountFrequency (%)
e 467
10.7%
o 387
 
8.9%
t 383
 
8.8%
a 367
 
8.4%
n 367
 
8.4%
i 353
 
8.1%
r 304
 
7.0%
s 245
 
5.6%
l 201
 
4.6%
c 196
 
4.5%
Other values (16) 1083
24.9%
Uppercase Letter
ValueCountFrequency (%)
A 21
13.2%
D 19
 
11.9%
C 13
 
8.2%
P 12
 
7.5%
M 8
 
5.0%
N 8
 
5.0%
I 8
 
5.0%
R 8
 
5.0%
F 6
 
3.8%
L 6
 
3.8%
Other values (14) 50
31.4%
Other Punctuation
ValueCountFrequency (%)
# 4
50.0%
. 1
 
12.5%
: 1
 
12.5%
, 1
 
12.5%
' 1
 
12.5%
Decimal Number
ValueCountFrequency (%)
0 3
33.3%
2 2
22.2%
3 2
22.2%
1 1
 
11.1%
9 1
 
11.1%
Space Separator
ValueCountFrequency (%)
685
100.0%
Dash Punctuation
ValueCountFrequency (%)
- 24
100.0%
Connector Punctuation
ValueCountFrequency (%)
_ 3
100.0%

Most occurring scripts

ValueCountFrequency (%)
Latin 4512
86.1%
Common 729
 
13.9%

Most frequent character per script

Latin
ValueCountFrequency (%)
e 467
 
10.4%
o 387
 
8.6%
t 383
 
8.5%
a 367
 
8.1%
n 367
 
8.1%
i 353
 
7.8%
r 304
 
6.7%
s 245
 
5.4%
l 201
 
4.5%
c 196
 
4.3%
Other values (40) 1242
27.5%
Common
ValueCountFrequency (%)
685
94.0%
- 24
 
3.3%
# 4
 
0.5%
0 3
 
0.4%
_ 3
 
0.4%
2 2
 
0.3%
3 2
 
0.3%
1 1
 
0.1%
9 1
 
0.1%
. 1
 
0.1%
Other values (3) 3
 
0.4%

Most occurring blocks

ValueCountFrequency (%)
ASCII 5241
100.0%

Most frequent character per block

ASCII
ValueCountFrequency (%)
685
13.1%
e 467
 
8.9%
o 387
 
7.4%
t 383
 
7.3%
a 367
 
7.0%
n 367
 
7.0%
i 353
 
6.7%
r 304
 
5.8%
s 245
 
4.7%
l 201
 
3.8%
Other values (53) 1482
28.3%

출판년도
Categorical

Distinct7
Distinct (%)12.5%
Missing0
Missing (%)0.0%
Memory size580.0 B
2019-02-01
28 
2019-02-02
17 
2019-02-10
6 
2019-02-06
 
2
2019-02-04
 
1
Other values (2)
 
2

Length

Max length10
Median length10
Mean length10
Min length10

Unique

Unique3 ?
Unique (%)5.4%

Sample

1st row2019-02-04
2nd row2019-02-08
3rd row2019-02-07
4th row2019-02-02
5th row2019-02-02

Common Values

ValueCountFrequency (%)
2019-02-01 28
50.0%
2019-02-02 17
30.4%
2019-02-10 6
 
10.7%
2019-02-06 2
 
3.6%
2019-02-04 1
 
1.8%
2019-02-08 1
 
1.8%
2019-02-07 1
 
1.8%

Length

2023-12-12T16:01:04.296604image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
Histogram of lengths of the category

Common Values (Plot)

2023-12-12T16:01:04.410446image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
ValueCountFrequency (%)
2019-02-01 28
50.0%
2019-02-02 17
30.4%
2019-02-10 6
 
10.7%
2019-02-06 2
 
3.6%
2019-02-04 1
 
1.8%
2019-02-08 1
 
1.8%
2019-02-07 1
 
1.8%

페이지 수
Text

Distinct43
Distinct (%)76.8%
Missing0
Missing (%)0.0%
Memory size580.0 B
2023-12-12T16:01:04.558053image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Length

Max length6
Median length5
Mean length5.3392857
Min length5

Characters and Unicode

Total characters299
Distinct characters13
Distinct categories4 ?
Distinct scripts2 ?
Distinct blocks1 ?
The Unicode Standard assigns character properties to each code point, which can be used to analyse textual variables.

Unique

Unique33 ?
Unique (%)58.9%

Sample

1st row107 p.
2nd row33 p.
3rd row52 p.
4th row44 p.
5th row50 p.
ValueCountFrequency (%)
p 56
50.0%
95 3
 
2.7%
54 3
 
2.7%
44 3
 
2.7%
49 2
 
1.8%
63 2
 
1.8%
35 2
 
1.8%
52 2
 
1.8%
59 2
 
1.8%
158 2
 
1.8%
Other values (34) 35
31.2%
2023-12-12T16:01:04.877484image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Most occurring characters

ValueCountFrequency (%)
56
18.7%
p 56
18.7%
. 56
18.7%
1 27
9.0%
4 21
 
7.0%
5 20
 
6.7%
3 11
 
3.7%
9 10
 
3.3%
8 9
 
3.0%
0 9
 
3.0%
Other values (3) 24
8.0%

Most occurring categories

ValueCountFrequency (%)
Decimal Number 131
43.8%
Space Separator 56
18.7%
Lowercase Letter 56
18.7%
Other Punctuation 56
18.7%

Most frequent character per category

Decimal Number
ValueCountFrequency (%)
1 27
20.6%
4 21
16.0%
5 20
15.3%
3 11
8.4%
9 10
 
7.6%
8 9
 
6.9%
0 9
 
6.9%
7 9
 
6.9%
6 8
 
6.1%
2 7
 
5.3%
Space Separator
ValueCountFrequency (%)
56
100.0%
Lowercase Letter
ValueCountFrequency (%)
p 56
100.0%
Other Punctuation
ValueCountFrequency (%)
. 56
100.0%

Most occurring scripts

ValueCountFrequency (%)
Common 243
81.3%
Latin 56
 
18.7%

Most frequent character per script

Common
ValueCountFrequency (%)
56
23.0%
. 56
23.0%
1 27
11.1%
4 21
 
8.6%
5 20
 
8.2%
3 11
 
4.5%
9 10
 
4.1%
8 9
 
3.7%
0 9
 
3.7%
7 9
 
3.7%
Other values (2) 15
 
6.2%
Latin
ValueCountFrequency (%)
p 56
100.0%

Most occurring blocks

ValueCountFrequency (%)
ASCII 299
100.0%

Most frequent character per block

ASCII
ValueCountFrequency (%)
56
18.7%
p 56
18.7%
. 56
18.7%
1 27
9.0%
4 21
 
7.0%
5 20
 
6.7%
3 11
 
3.7%
9 10
 
3.3%
8 9
 
3.0%
0 9
 
3.0%
Other values (3) 24
8.0%

언어
Categorical

CONSTANT 

Distinct1
Distinct (%)1.8%
Missing0
Missing (%)0.0%
Memory size580.0 B
(EN)
56 

Length

Max length4
Median length4
Mean length4
Min length4

Unique

Unique0 ?
Unique (%)0.0%

Sample

1st row(EN)
2nd row(EN)
3rd row(EN)
4th row(EN)
5th row(EN)

Common Values

ValueCountFrequency (%)
(EN) 56
100.0%

Length

2023-12-12T16:01:05.079696image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
Histogram of lengths of the category

Common Values (Plot)

2023-12-12T16:01:05.218884image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
ValueCountFrequency (%)
en 56
100.0%

키워드
Text

UNIQUE 

Distinct56
Distinct (%)100.0%
Missing0
Missing (%)0.0%
Memory size580.0 B
2023-12-12T16:01:05.548639image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Length

Max length188
Median length130.5
Mean length122.01786
Min length72

Characters and Unicode

Total characters6833
Distinct characters35
Distinct categories5 ?
Distinct scripts2 ?
Distinct blocks1 ?
The Unicode Standard assigns character properties to each code point, which can be used to analyse textual variables.

Unique

Unique56 ?
Unique (%)100.0%

Sample

1st rowSPECIFICATIONS; SIMULATION; REDUCTION; DETECTION; COMPUTER CODES; ENTROPY; SAFETY; PERFORMANCE
2nd rowDISPERSIONS; COMPLEX TERRAIN; COMPUTER CALCULATIONS; POLLUTANTS; GAUSSIAN PROCESSES; TURBULENCE; ACCURACY; USES; REGULATIONS
3rd rowEMISSION; IRRADIATION; POLYSTYRENE; THICKNESS; FLUORESCENCE; PHOTOLUMINESCENCE; SPECTROSCOPY; ELECTRON BEAMS; CONTROL; NANOSTRUCTURES
4th rowCROSS SECTIONS; ANISOTROPY; SCATTERING; EQUATIONS; EXTRAPOLATION; ERRORS; FAST NEUTRONS; COMPUTER CALCULATIONS; DECOMPOSITION
5th rowDESIGN; CRYSTALS; RESOLUTION; SCINTILLATIONS; TUBES; COLLIMATORS; GAMMA CAMERAS; SPATIAL RESOLUTION; SENSITIVITY; PHOTON TRANSPORT; COMPUTERIZED SIMULATION; MONTE CARLO METHOD; CORRECTIONS
ValueCountFrequency (%)
performance 17
 
2.3%
nuclear 14
 
1.9%
design 13
 
1.8%
reactors 13
 
1.8%
control 13
 
1.8%
power 13
 
1.8%
fuel 13
 
1.8%
simulation 11
 
1.5%
reactor 11
 
1.5%
computer 11
 
1.5%
Other values (316) 607
82.5%
2023-12-12T16:01:06.110367image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Most occurring characters

ValueCountFrequency (%)
680
 
10.0%
E 600
 
8.8%
T 484
 
7.1%
I 484
 
7.1%
S 480
 
7.0%
O 453
 
6.6%
R 452
 
6.6%
; 451
 
6.6%
A 431
 
6.3%
N 411
 
6.0%
Other values (25) 1907
27.9%

Most occurring categories

ValueCountFrequency (%)
Uppercase Letter 5684
83.2%
Space Separator 680
 
10.0%
Other Punctuation 451
 
6.6%
Dash Punctuation 10
 
0.1%
Decimal Number 8
 
0.1%

Most frequent character per category

Uppercase Letter
ValueCountFrequency (%)
E 600
10.6%
T 484
 
8.5%
I 484
 
8.5%
S 480
 
8.4%
O 453
 
8.0%
R 452
 
8.0%
A 431
 
7.6%
N 411
 
7.2%
C 377
 
6.6%
L 264
 
4.6%
Other values (16) 1248
22.0%
Decimal Number
ValueCountFrequency (%)
2 2
25.0%
1 2
25.0%
6 1
12.5%
5 1
12.5%
3 1
12.5%
4 1
12.5%
Space Separator
ValueCountFrequency (%)
680
100.0%
Other Punctuation
ValueCountFrequency (%)
; 451
100.0%
Dash Punctuation
ValueCountFrequency (%)
- 10
100.0%

Most occurring scripts

ValueCountFrequency (%)
Latin 5684
83.2%
Common 1149
 
16.8%

Most frequent character per script

Latin
ValueCountFrequency (%)
E 600
10.6%
T 484
 
8.5%
I 484
 
8.5%
S 480
 
8.4%
O 453
 
8.0%
R 452
 
8.0%
A 431
 
7.6%
N 411
 
7.2%
C 377
 
6.6%
L 264
 
4.6%
Other values (16) 1248
22.0%
Common
ValueCountFrequency (%)
680
59.2%
; 451
39.3%
- 10
 
0.9%
2 2
 
0.2%
1 2
 
0.2%
6 1
 
0.1%
5 1
 
0.1%
3 1
 
0.1%
4 1
 
0.1%

Most occurring blocks

ValueCountFrequency (%)
ASCII 6833
100.0%

Most frequent character per block

ASCII
ValueCountFrequency (%)
680
 
10.0%
E 600
 
8.8%
T 484
 
7.1%
I 484
 
7.1%
S 480
 
7.0%
O 453
 
6.6%
R 452
 
6.6%
; 451
 
6.6%
A 431
 
6.3%
N 411
 
6.0%
Other values (25) 1907
27.9%

초록
Text

UNIQUE 

Distinct56
Distinct (%)100.0%
Missing0
Missing (%)0.0%
Memory size580.0 B
2023-12-12T16:01:06.489967image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Length

Max length1024
Median length1024
Mean length1016.5536
Min length690

Characters and Unicode

Total characters56927
Distinct characters77
Distinct categories10 ?
Distinct scripts2 ?
Distinct blocks1 ?
The Unicode Standard assigns character properties to each code point, which can be used to analyse textual variables.

Unique

Unique56 ?
Unique (%)100.0%

Sample

1st rowSoftware testability for specification in statechart and for source code is suggested in this thesis. The suggested testability for specification in statechart is based on the degree of required efforts for testing, and is based on the number of test cases required for the transformed finite state machine of the statechart. The statechart is transformed into extended finite state machine by flattening the hierarchy and concurrency of the statechart and expanded into finite state machine by splitting the conditional transitions. The proposed testability measure has been applied to the statechart of the low pressurizer pressure trip function of the plant protection system and statechart of the coffee vending machine. The testability of the specification in statechart can be improved either by introducing additional outputs to the statechart or by modeling the statechart to reduce the number of test cases required for the transformed finite state machine. To reduce the number of required test cases, the statecha
2nd rowAlthough widely used to calculate the concentration of chemical pollutants or radionuclide released from power plants in flat terrain, the Gaussian Plume model (GP) still remains several limitations due to assumptions of homogenous turbulent, non-zero wind condition and/or steady state release that make the model inaccurate in predicting pollutant concentration in flat terrain. Estimation of pollutant concentration in complex terrain is more difficult for GP because of terrain-induced effects. In this study, a modified Lagrangian Puff model is proposed for more accurate estimation of ground level pollutant concentration both in flat terrain and complex terrain than is found with GP. The new model also is capable of dealing with inhomogeneous turbulent, calm wind condition and unsteady state release, and is designed for releases within an area of a hundred of kilometers in a time scale of several hours. A compact program was built in Matlab environment to calculate ground-level pollutant concentration. The res
3rd rowPromising blue and white luminescence were demonstrated from energetic electron irradiated polystyrene (PS) film which was spin coated on silicon substrate with 8#mu#m thickness. The fluorescence properties were characterized by using photoluminescence spectroscopy. Interestingly, pristine PS did not show any visible PL emission, however, irradiated samples exhibited blue-white fluorescence emission when PS film was irradiated by electron beam at fluence from 1.7x10"1"5 to 9.5x10"1"6 cm"-"2 with 50 keV. The light emitting region can be patterned into any size and shape by controlling the irradiated region. In addition, by adopting PS nanostructure nanoscale light emitter can be easily made. The origins of fluorescence were analyzed with FTIR, UV/Vis and NMR spectroscopy which identify the changes in chemical structure of the irradiated PS film. The results of spectroscopy suggested that light emission of electron-irradiated PS originate from clusterization of multi ring sp"2 carbon cluster induced by chemical
4th rowHandling highly anisotropic scattering of fast neutrons with conventional methods usually means that high order Legendre expansions are necessary to obtain correct angular fluxes. This drawback in standard transport calculations is avoided by applying the Boltzmann-Fokker-Planck (BFP) equation which has been used in both neutral and charged-particle transport problems. Previously, Caro and Ligou, and Morel have introduced Fokker-Planck decomposition methods, which decompose elastic scattering cross section into forward-peaked and smooth components. A new method for decomposing scattering cross sections for Boltzmann-Fokker-Planck equation is presented. We start from the basic data #sigma#(#mu#, E) (given by ENDF/B-VI) to get more correctly determined BFP data. In this method, we use Legendre expansion for smooth component and exponential function which Caro and Ligou used for forward-peaked component. In addition, by using RMS errors and an extra degree of freedom #sigma#_e_x_t, we conserve both moments and s
5th rowFor scintillation camera, recently there have been many research of gamma imager based on position-sensitive photomultiplier tube (PSPMT) coupled with optical guide and pixellated crystal array. For its design, there is a need to optimize several parameters of collimator, crystal with high sensitivity and high spatial resolution. In this study, theoretical investigation and experimental analysis have been performed for the better design of a small gamma camera based on PSPMT through several experiments. The optical photon transport within a scintillating crystal and the emitted photon distribution were simulated by using Monte Carlo method. Based on this simulation, we estimated final photon images from the PSPMT model(R2486) by accounting for the resistive network method. As using this program composed of Monte Carlo method and the resistive network method, we described the whole system of gamma imager and decided many parameters effecting sensitivity and spatial resolution for design of gamma imager. From t
ValueCountFrequency (%)
the 656
 
7.6%
of 339
 
3.9%
and 290
 
3.4%
in 194
 
2.3%
to 171
 
2.0%
is 134
 
1.6%
a 129
 
1.5%
for 121
 
1.4%
with 80
 
0.9%
was 78
 
0.9%
Other values (2172) 6423
74.6%
2023-12-12T16:01:06.953727image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/

Most occurring characters

ValueCountFrequency (%)
8564
15.0%
e 5832
 
10.2%
t 4158
 
7.3%
a 3549
 
6.2%
i 3495
 
6.1%
n 3332
 
5.9%
o 3293
 
5.8%
s 3010
 
5.3%
r 2920
 
5.1%
c 1897
 
3.3%
Other values (67) 16877
29.6%

Most occurring categories

ValueCountFrequency (%)
Lowercase Letter 45254
79.5%
Space Separator 8564
 
15.0%
Uppercase Letter 1500
 
2.6%
Other Punctuation 892
 
1.6%
Decimal Number 367
 
0.6%
Dash Punctuation 164
 
0.3%
Open Punctuation 83
 
0.1%
Close Punctuation 82
 
0.1%
Connector Punctuation 14
 
< 0.1%
Math Symbol 7
 
< 0.1%

Most frequent character per category

Lowercase Letter
ValueCountFrequency (%)
e 5832
12.9%
t 4158
 
9.2%
a 3549
 
7.8%
i 3495
 
7.7%
n 3332
 
7.4%
o 3293
 
7.3%
s 3010
 
6.7%
r 2920
 
6.5%
c 1897
 
4.2%
d 1864
 
4.1%
Other values (16) 11904
26.3%
Uppercase Letter
ValueCountFrequency (%)
T 208
13.9%
A 133
 
8.9%
C 115
 
7.7%
I 115
 
7.7%
P 109
 
7.3%
S 83
 
5.5%
F 82
 
5.5%
R 73
 
4.9%
M 70
 
4.7%
N 65
 
4.3%
Other values (15) 447
29.8%
Decimal Number
ValueCountFrequency (%)
0 102
27.8%
1 60
16.3%
2 49
13.4%
5 39
 
10.6%
3 25
 
6.8%
6 25
 
6.8%
4 22
 
6.0%
9 17
 
4.6%
8 17
 
4.6%
7 11
 
3.0%
Other Punctuation
ValueCountFrequency (%)
. 404
45.3%
, 334
37.4%
# 55
 
6.2%
/ 39
 
4.4%
" 18
 
2.0%
: 16
 
1.8%
' 15
 
1.7%
% 11
 
1.2%
Math Symbol
ValueCountFrequency (%)
= 5
71.4%
< 1
 
14.3%
> 1
 
14.3%
Space Separator
ValueCountFrequency (%)
8564
100.0%
Dash Punctuation
ValueCountFrequency (%)
- 164
100.0%
Open Punctuation
ValueCountFrequency (%)
( 83
100.0%
Close Punctuation
ValueCountFrequency (%)
) 82
100.0%
Connector Punctuation
ValueCountFrequency (%)
_ 14
100.0%

Most occurring scripts

ValueCountFrequency (%)
Latin 46754
82.1%
Common 10173
 
17.9%

Most frequent character per script

Latin
ValueCountFrequency (%)
e 5832
12.5%
t 4158
 
8.9%
a 3549
 
7.6%
i 3495
 
7.5%
n 3332
 
7.1%
o 3293
 
7.0%
s 3010
 
6.4%
r 2920
 
6.2%
c 1897
 
4.1%
d 1864
 
4.0%
Other values (41) 13404
28.7%
Common
ValueCountFrequency (%)
8564
84.2%
. 404
 
4.0%
, 334
 
3.3%
- 164
 
1.6%
0 102
 
1.0%
( 83
 
0.8%
) 82
 
0.8%
1 60
 
0.6%
# 55
 
0.5%
2 49
 
0.5%
Other values (16) 276
 
2.7%

Most occurring blocks

ValueCountFrequency (%)
ASCII 56927
100.0%

Most frequent character per block

ASCII
ValueCountFrequency (%)
8564
15.0%
e 5832
 
10.2%
t 4158
 
7.3%
a 3549
 
6.2%
i 3495
 
6.1%
n 3332
 
5.9%
o 3293
 
5.8%
s 3010
 
5.3%
r 2920
 
5.1%
c 1897
 
3.3%
Other values (67) 16877
29.6%

Correlations

2023-12-12T16:01:07.071683image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
저자논문구분제목출판년도페이지 수키워드초록
저자1.0001.0001.0001.0001.0001.0001.000
논문구분1.0001.0001.0000.1341.0001.0001.000
제목1.0001.0001.0001.0001.0001.0001.000
출판년도1.0000.1341.0001.0000.8781.0001.000
페이지 수1.0001.0001.0000.8781.0001.0001.000
키워드1.0001.0001.0001.0001.0001.0001.000
초록1.0001.0001.0001.0001.0001.0001.000
2023-12-12T16:01:07.176966image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
논문구분출판년도
논문구분1.0000.129
출판년도0.1291.000
2023-12-12T16:01:07.276259image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
논문구분출판년도
논문구분1.0000.129
출판년도0.1291.000

Missing values

2023-12-12T16:01:02.561426image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
A simple visualization of nullity by column.
2023-12-12T16:01:02.674674image/svg+xmlMatplotlib v3.7.2, https://matplotlib.org/
Nullity matrix is a data-dense display which lets you quickly visually pick out patterns in data completion.

Sample

저자소속논문구분제목출판년도페이지 수언어키워드초록
0Sohn, Se DoKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Dr. Eng.)Quantitative evaluation of software testability for specification in statechart and for source code2019-02-04107 p.(EN)SPECIFICATIONS; SIMULATION; REDUCTION; DETECTION; COMPUTER CODES; ENTROPY; SAFETY; PERFORMANCESoftware testability for specification in statechart and for source code is suggested in this thesis. The suggested testability for specification in statechart is based on the degree of required efforts for testing, and is based on the number of test cases required for the transformed finite state machine of the statechart. The statechart is transformed into extended finite state machine by flattening the hierarchy and concurrency of the statechart and expanded into finite state machine by splitting the conditional transitions. The proposed testability measure has been applied to the statechart of the low pressurizer pressure trip function of the plant protection system and statechart of the coffee vending machine. The testability of the specification in statechart can be improved either by introducing additional outputs to the statechart or by modeling the statechart to reduce the number of test cases required for the transformed finite state machine. To reduce the number of required test cases, the statecha
1Trinh, Huu ToanKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A modified Lagrangian puff model for pollutant dispersion in complex terrain2019-02-0833 p.(EN)DISPERSIONS; COMPLEX TERRAIN; COMPUTER CALCULATIONS; POLLUTANTS; GAUSSIAN PROCESSES; TURBULENCE; ACCURACY; USES; REGULATIONSAlthough widely used to calculate the concentration of chemical pollutants or radionuclide released from power plants in flat terrain, the Gaussian Plume model (GP) still remains several limitations due to assumptions of homogenous turbulent, non-zero wind condition and/or steady state release that make the model inaccurate in predicting pollutant concentration in flat terrain. Estimation of pollutant concentration in complex terrain is more difficult for GP because of terrain-induced effects. In this study, a modified Lagrangian Puff model is proposed for more accurate estimation of ground level pollutant concentration both in flat terrain and complex terrain than is found with GP. The new model also is capable of dealing with inhomogeneous turbulent, calm wind condition and unsteady state release, and is designed for releases within an area of a hundred of kilometers in a time scale of several hours. A compact program was built in Matlab environment to calculate ground-level pollutant concentration. The res
2Lee, Hyeok MooKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Blue and white light emission from electron irradiated polystyrene2019-02-0752 p.(EN)EMISSION; IRRADIATION; POLYSTYRENE; THICKNESS; FLUORESCENCE; PHOTOLUMINESCENCE; SPECTROSCOPY; ELECTRON BEAMS; CONTROL; NANOSTRUCTURESPromising blue and white luminescence were demonstrated from energetic electron irradiated polystyrene (PS) film which was spin coated on silicon substrate with 8#mu#m thickness. The fluorescence properties were characterized by using photoluminescence spectroscopy. Interestingly, pristine PS did not show any visible PL emission, however, irradiated samples exhibited blue-white fluorescence emission when PS film was irradiated by electron beam at fluence from 1.7x10"1"5 to 9.5x10"1"6 cm"-"2 with 50 keV. The light emitting region can be patterned into any size and shape by controlling the irradiated region. In addition, by adopting PS nanostructure nanoscale light emitter can be easily made. The origins of fluorescence were analyzed with FTIR, UV/Vis and NMR spectroscopy which identify the changes in chemical structure of the irradiated PS film. The results of spectroscopy suggested that light emission of electron-irradiated PS originate from clusterization of multi ring sp"2 carbon cluster induced by chemical
3Kim, Jong WoonKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Generation of isotropic and anisotropic scattering cross section for Boltzmann-Fokker-planck equation via extrapolation exponential function and minimized RMS errors2019-02-0244 p.(EN)CROSS SECTIONS; ANISOTROPY; SCATTERING; EQUATIONS; EXTRAPOLATION; ERRORS; FAST NEUTRONS; COMPUTER CALCULATIONS; DECOMPOSITIONHandling highly anisotropic scattering of fast neutrons with conventional methods usually means that high order Legendre expansions are necessary to obtain correct angular fluxes. This drawback in standard transport calculations is avoided by applying the Boltzmann-Fokker-Planck (BFP) equation which has been used in both neutral and charged-particle transport problems. Previously, Caro and Ligou, and Morel have introduced Fokker-Planck decomposition methods, which decompose elastic scattering cross section into forward-peaked and smooth components. A new method for decomposing scattering cross sections for Boltzmann-Fokker-Planck equation is presented. We start from the basic data #sigma#(#mu#, E) (given by ENDF/B-VI) to get more correctly determined BFP data. In this method, we use Legendre expansion for smooth component and exponential function which Caro and Ligou used for forward-peaked component. In addition, by using RMS errors and an extra degree of freedom #sigma#_e_x_t, we conserve both moments and s
4Chi, Yong KiKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Design of compact gamma imager based on pixellated crystal array with high resolution2019-02-0250 p.(EN)DESIGN; CRYSTALS; RESOLUTION; SCINTILLATIONS; TUBES; COLLIMATORS; GAMMA CAMERAS; SPATIAL RESOLUTION; SENSITIVITY; PHOTON TRANSPORT; COMPUTERIZED SIMULATION; MONTE CARLO METHOD; CORRECTIONSFor scintillation camera, recently there have been many research of gamma imager based on position-sensitive photomultiplier tube (PSPMT) coupled with optical guide and pixellated crystal array. For its design, there is a need to optimize several parameters of collimator, crystal with high sensitivity and high spatial resolution. In this study, theoretical investigation and experimental analysis have been performed for the better design of a small gamma camera based on PSPMT through several experiments. The optical photon transport within a scintillating crystal and the emitted photon distribution were simulated by using Monte Carlo method. Based on this simulation, we estimated final photon images from the PSPMT model(R2486) by accounting for the resistive network method. As using this program composed of Monte Carlo method and the resistive network method, we described the whole system of gamma imager and decided many parameters effecting sensitivity and spatial resolution for design of gamma imager. From t
5Oh, Seung JinKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Effects of hydrogen concentration on fracture toughness of CANDU pressure tube2019-02-0252 p.(EN)CANDU TYPE REACTORS; PRESSURE TUBES; FRACTURE PROPERTIES; HYDROGEN; MORPHOLOGY; OPTICAL MICROSCOPES; CRACK PROPAGATION; DUCTILE-BRITTLE TRANSITIONS; STRESSES; HYDRIDESThe effects of hydrogen concentration on the axial fracture toughness of Zr-2.5 wt% Nb CANDU pressure tube material have been determined from room temperature to 300 .deg. C. The specimens was charged to 50, 100, 150, 200ppm of hydrogen. To observe hydride morphology and measure volume fraction, optical microscope was used. The crack growth during fracture toughness test was measured by direct current potential drop method. Fracture toughness characterized by J-R curve and dJ/da was discussed in terms of hydrogen concentration. As hydrogen concentration increased, hydride volume fraction, thickness and length increased. However, interhydride spacing remained nearly constant. At room temperature, fracture toughness decreased rapidly with increasing hydrogen concentration until hydrogen concentration was below 100ppm. However, fracture toughness remained at a similar level at above 100ppm. Ductile-brittle transition temperature increased slightly when hydrogen concentration increased. At high temperature, fract
6Sheen, Jae JonKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A study on the radiation shielding analysis for LILW vitrification facility2019-02-0246 p.(EN)VITRIFICATION; LOW-LEVEL RADIOACTIVE WASTES; INTERMEDIATE-LEVEL RADIOACTIVE WASTES; SHIELDING; RADIATIONS; REDUCTION; CRYSTALS; LEACHING; EFFICIENCY; MAINTENANCEIn recent years, NETEC of KHNP is planning the vitrification plant for LILW(Low- and Intermediate- Level Waste). It has mainly two advantages. One is that it can reduce the volume of LILW and the other is that it can produce vitrified crystals which show little leaching. Through these advantages, it is predicted that the vitrification plant will treat the LILW discharged from the Uljin unit 5 and 6 in future. But until now, there has been no experience in construction and operation of a vitrification plant in Korea. Therefore, by carrying out radiation shielding analysis which is an essential part of the safety analysis of vitrification plants, this research was conducted to acquire information that can assist in the detail design and operation plan of vitrification plants hereafter. In this study, the sensitivity analysis for the equivalent dose rate in field according to the distance and shielding material, was performed. As a result, it was founded that the effect of the thickness of the 1's"t shielding ma
7Han, Kyu HyunKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Thermal hydraulic analysis of thorium fuel assemblies loaded with annular seed pins2019-02-0273 p.(EN)THERMAL HYDRAULICS; FUEL ASSEMBLIES; FUEL PINS; PRESSURE DROP; HEAT FLUX; MIXING; REACTORSThermal hydraulic characteristics of thorium-based fuel assemblies loaded with annular seed pins have been analyzed using MATRA_A combined with MATRA, and compared with those of the existing thorium-based assemblies. MATRA and MATRA_A showed good agreements for the pressure drops at the internal subchannels. The pressure drop generally increased in the cases of the assemblies loaded with annular seed pins due to the larger wetted perimeter, but an exception existed. In the inner subchannels of the seed pins, mass fluxes were high due to the grid form losses in the outer subchannels. About 43% of the heat generated from the seed pin flowed into the inner subchannel and the rest into the outer subchannel, which implies the inner to outer wall heat flux ratio was approximately 1.2. When the relative annular seed pin power is higher, the inner to outer wall heat flux ratio and inner subchannel mass flux are lower. The maximum temperatures of the annular seed pins were slightly above 500 .deg. C. The MDNBRs of the
8Lee, Yong KwanKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Performance test evaluation methodology for operator training simulator2019-02-0231 p.(EN)TRAINING; PERFORMANCE TESTING; TRANSIENTS; VALIDATION; SIMULATION; MANPOWER; PLANNINGA methodology of performance test evaluation is developed to determine minimum sets for transient tests and malfunction tests, which represent the whole performance of a full-scope simulator. EPRI's transient selection matrix methodology is applied to 16 transients of KNPEC no.2 ( Kori Nuclear Power Education Center ) simulator. It turns out that its minimum set includes 6 transients. The subroutine invocation test is performed to validate the EPRI transient selection matrix methodology. For the malfunction tests we develop 108 dynamic modes which represent the specific characteristics of each system. Applying the same methodology for the malfunction tests, we classify 160 malfunctions into 16 specific systems. Its minimum set includes 36 malfunctions. When the present methodology is applied to the simulator operability test, it is estimated that it enables us not only to save more than 50% of manpower and time but also to provide a standard to make a qualification plan for a new simulator
9Yook, Dae SikKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A study on the prediction of tritium behavior in rice plant after a short-term exposure of HTO2019-02-0259 p.(EN)TRITIUM OXIDES; TRITIUM; FORECASTING; RICE; CANDU TYPE REACTORS; KAERI; CONTAMINATION; SOILS; INGESTIONIn many Asian countries including Korea, rice is a very important food crop. Its grain is consumed by humans and its straw is used to feed animals. In Korea, there are four CANDU type reactors that release relatively large amounts of tritium into the environment. Since 1997, KAERI (Korea Atomic Energy Research Institute) has carried out the experimental studies to obtain domestic data for various parameters concerning the direct contamination of plant. In this study, the behavior of tritium in the rice plant is predicted and compared to the measurement performed at KAERI. Using the conceptual model of the soil-plant-atmosphere tritiated water transport system which was suggested by Charles E. Murphy, tritium concentrations in the soil and in the leaves relative to time were derived. For the effect of tritium concentration in the soil, the tritium concentrations in leaves are described by a double exponential model. On the other hand if the tritium concentration in the soil is disregarded, the tritium concentr
저자소속논문구분제목출판년도페이지 수언어키워드초록
46Jo, Chang KeunKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Dr. Eng.)Graphite-filled MOX fuel design for fully loaded PWR cores2019-02-0195 p.(EN)DESIGN; PWR TYPE REACTORS; REACTOR CORES; USES; MIXED OXIDE FUELS; VOIDS; BURNUP; EFFICIENCY; FUEL ASSEMBLIESThe use of recycled plutonium plays an important role in saving natural uranium resources. During the past 40 years, many researches have been performed for the use of recycled plutonium. Currently, the reprocessed plutonium is used in a mixed-oxide (MOX) fuel form in light water reactors (LWRs). However, the MOX fuel loading is currently limited to 1/3 or half of the core. This partial loading results in heterogeneous cores where interface problems appear between uranium and plutonium assemblies due to the discrepancies between effective cross sections of the uranium and plutonium isotopes. The resulting need to zone the fuel enrichment inside the fuel assembly leads to #approx#10% additional manufacturing costs. Consequently, there is a growing need for and interest in a full MOX core for better utilization of the recycled plutonium and for weapon's plutonium disposition. In order to maximize the benefit of plutonium recycling in the current LWR cores, recently, a significant amount of researches has been p
47Koo, Seo RyongKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A method of formal requirement analysis for NPP I and C systems based on object-oriented UML modeling with software cost reduction2019-02-0159 p.(EN)COST; REDUCTION; CONTROL SYSTEMS; NUCLEAR POWER PLANTS; INSPECTION; ENGINEERED SAFETY SYSTEMS; DETECTIONIn this work, a formal requirement analysis method for Nuclear Power Plant (NPP) I and C systems is suggested. This method uses Unified Modeling Language (UML) for modeling systems visually and Software Cost Reduction (SCR) for checking the system models formally. Since object-oriented methods enable us to analyze problems in terms of the objects in a real system, the UML models are useful for understanding the problems and communicating with people involved in a project. In order to analyze problems more formally, SCR is used and the UML models are converted into the SCR tabular notations. T his work tries to acquire the flow-through from UML models to SCR specifications by suggesting additional syntactic extensions for UML notation and a converting procedure in this work. The proposed method has been applied to the Dynamic Safety System (DSS) and the Inadequate Core Cooling Monitoring System (ICCMS). Through these applications, some errors have been detected in the existing system requirements. Furthermore,
48Kim, Young SooKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Development of a charge collection model in CdZnTe detectors and its application to Gamma-ray spectrum2019-02-0140 p.(EN)PERFORMANCE; GAMMA SPECTRA; RADIATION DETECTORS; EFFICIENCY; COMPUTER CALCULATIONS; CAMERAS; DESIGN; TRANSPORTThe performance of a cadmium zinc telluride (CdZnTe) room temperature radiation detectors is mainly limited by the charge transport properties. In this study, charge transport properties were investigated through three models and a simple model for the charge collection process in CdZnTe radiation detectors of m-i-m diode structure was developed. The developed model can take the input variables of material properties, such as mobility and lifetime of electrons and holes, as well as the operation parameters, such as the applied bias voltage, pulse shaping time, and the incident direction and the energy of gamma-rays. Using the developed model, the pulse height spectra of mono energy gamma-rays are analyzed. The measured charge collection efficiency was agreed well with the model calculations, and the distortion of the photo-peak spectrum was understood well by the charge collection model. The developed model will be useful in quick evaluation of the CdZnTe detector diode as well as the design of optimal detect
49Bang, In CheolKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A photographic study on the near-wall bubble behavior in subcooled flow boiling2019-02-0154 p.(EN)SUBCOOLED BOILING; BUBBLES; CRITICAL HEAT FLUX; PERFORMANCE; ATMOSPHERIC PRESSURE; THICKNESS; CAMERAS; VAPORS; SURFACESThe behavior of near-wall bubbles in subcooled flow boiling has been investigated photographically to identify the physical mechanisms of critical heat flux at subcooled and low-quality conditions. Visualization experiments were performed for water flow in vertical rectangular channels under atmospheric pressure for mass fluxes below 2020 kg/m"2s. The thickness and other features of the near-wall bubble layer were examined with the aid of a high-speed camera, a still camera and an 8 mm-camera recorder. The number of activated nucleation sites increased as the wall heat flux was increased. At sufficiently high heat flux about 5-7.5 MW/m"2, the appearance of vapor clot or blanket on the heated surface made a role of an obstacle between main liquid region and the region near heater. At such high heat flux, three characteristic regions were observed in the heated channel: (a) a superheated liquid layer with attached bubbles, (b) a flowing bubble layer consisting of large coalesced bubbles over the attached bubble
50Son, Han SeongKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Dr. Eng.)Verification and validation environment construction based on colored Petri Nets for NPP I and C software2019-02-01158 p.(EN)VERIFICATION; VALIDATION; NUCLEAR POWER PLANTS; DIGITAL SYSTEMS; NUCLEAR INDUSTRY; RADIATION PROTECTION; DESIGN; FAILURES; SAFETYThe use of digital systems is on increase in nuclear industry in recent years. Therefore, the importance of system verification and validation (V/V) is more emphasized in view of the nuclear safety. There is, however, no generally applicable software design process and software failure model that is sufficiently accurate to enable reliability or safety predictions to be made for safety critical systems. In addition, until nearly a decade ago, there was a lack of emphasis on V/V in the earlier stages of software development, thus consequently heavy reliance was placed upon testing. Therefore, we have a lot of difficulty in performing V/V practically and effectively though there trends to be more emphasis upon introducing V/V activities earlier and throughout the software development process. In order to overcome the difficulty, many researchers have proposed various software V/V techniques and software quality control methods. The main objective of this research is to construct an environment for V/V of safety
51Ahn, Seong KyuKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)A study on characteristics of solid state detector for X-ray computed tomography2019-02-0144 p.(EN)COMPUTERIZED TOMOGRAPHY; DETECTION; SCINTILLATIONS; EFFICIENCY; ABSORPTION; DESIGN; PERFORMANCE; GEOMETRY; COMPUTER CALCULATIONSThe detective quantum efficiency (DQE) of solid state detectors using cadmium tungstate scintillation crystal for x-ray computed tomography (CT) and various factors, which affect the DQE, were estimated by calculations using analytic model and Monte Carlo method. The scattered photon intensity and the cross talk ratio were simulated using MCNP code, and their reduction by collimators and spacers was calculated for their various sizes. The effects of collimators and spacers on the geometric efficiency were also taken into consideration. The absorption efficiency of cadmium tungstate crystal and the light col ection efficiency onto photodiodes surface for various surface conditions of crystal and reflectors were also calculated using DETECT code. As the results, there was no significant effect of cross talk and variations of the collection efficiency were very large and strongly affected the detector sensitivity. The absorption efficiency increased and the light collection efficiency decreased as the crystal he
52Lee, Sang IkKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Improvement of hydraulic scheme in TRAC using the 3-field model2019-02-0161 p.(EN)HYDRAULICS; EQUATIONS; DROPLETS; MOTION; COMPUTER CALCULATIONS; COMPUTERIZED SIMULATION; VOID FRACTION; PIPES; CORRELATIONSTRAC-PF1 is modified to include the 3-field governing equations and physical model related to the droplet field. In deriving the present 3-field model, the droplet equation of motion used in the study of Varone and Rohsenow is used to calculate the relative velocity of the droplet and gas. The governing equations and physical models related to the droplet field are based on the 3-field model of COBRA-TF and the finite difference equations of these modified governing equations are derived in the form of TRAC-PF1. New solution matrix elements are derived and these are adopted to the solution step of TRAC-PF1. The simulation results by the modified code are compared with these from Ishii's equilibrium entrainment correlation. It is found out that the simulation results depend on inlet void fraction and pipe diameter. When inlet void fraction is 0.9 or higher and the pipe diameter is larger than 3cm, the simulation results approach Ishii's correlation
53Lee, Gil SooKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Parallelization and coarse mesh rebalance acceleration of the method of characteristics in neutron transport theory2019-02-0135 p.(EN)FINITE DIFFERENCE METHOD; ACCELERATION; NEUTRON TRANSPORT THEORY; EQUATIONS; ANISOTROPY; SCATTERING; EIGENVALUES; REDUCTIONThe method of characteristics, one of the methods which solve neutron transport equation, combines desirable features of the integral transport and S_N methods and gives accurate solutions in complex geometries, strong absorber problems, strong anisotropic problems and so on. Because this method divides neutron directions like S_N and performs transport calculation along each parallel characteristic line, it needs fine angle division and many parallel characteristic lines for high accuracy. Besides, like most of the transport methods, it requires long computing time for scattering dominant problems and problems with significant upscattering. The long computing time incurred by scattering dominance or upscattering can be reduced by using acceleration methods and that incurred by many rays and fine angle divisions by using parallel computation. In this study, the CRX lattice calculation code based on the method of characteristics was accelerated with the coarse mesh rebalance (CMR) method for inner iteration an
54Koh, Kwang YongKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)SMV model-based safety analysis of software requirements2019-02-0663 p.(EN)SAFETY ANALYSIS; CONTROL; NUCLEAR POWER PLANTS; USES; DAMAGE; SAFETY; WOLSUNG-1 REACTOR; ERRORS; VERIFICATIONSoftware control in safety-critical systems such as aerospace, military, nuclear power plant, and medical applications has become increasingly common in recent years. When software is used as a control agent in these systems, safety becomes a paramount concern. In the worst case, software malfunctions, i.e. unsafe software control outputs can result in serious and unacceptable consequences such as death, injury, or environmental damage Of all the phase in software development, the requirements analysis phase is generally considered to play the most critical role in determining the overall software safety and quality because defective requirements specifications may result in errors which propagate to subsequent phases of software development and mistakes made during the requirements analysis phase can easily introduce faults which subsequently lead to accidents. Fault tree analysis is one of the most frequently applied safety analysis techniques when developing safety-critical industrial systems such as softw
55Lee, Young SeungKorea Advanced Institute of Science and Technology, Daejeon (KR)Thesis (Mr. Eng.)Cost savings in nuclear power generating stations by power factor improvement2019-02-0663 p.(EN)NUCLEAR POWER; POWER FACTOR; COST; ELECTRICITY; EFFICIENCY; WOLSUNG-2 REACTOR; PERFORMANCEA shortage of natural resources coupled with high oil prices leads people to be frugal in terms of living costs as well as energy costs in South Korea. Furthermore, de facto competition in the generation sector of the electricity industry exists now that the generation business of KEPCO has been spun off into six power generation subsidiaries. KHNP, generating 38.6 % of the total electricity, is felt keenly when it comes to efficient use of electricity with cost savings. A power factor improvement was proposed as a method for efficient use of electricity with cost savings. The power factor of nuclear power generating stations is about 80%, and this power factor improvement is useful in the situation of a low power factor for efficient use of electricity with cost savings. In this paper, the analyses of economical efficiency and performance were implemented when a synchronous condenser was used for a power factor improvement. For economical efficiency, a break-even analysis was used. In order to obtain capital