• 제목/요약/키워드: LIEF

검색결과 20건 처리시간 0.019초

연변지역 조선족의 가족생활 및 육아방식의 실태조사 (- A Survey of Child-Rearing Practive and Family Life of Korean-Chinese Families in Yanbin Area-)

  • 조복희
    • 대한가정학회지
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    • 제31권1호
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    • pp.35-44
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    • 1993
  • Two hundred and fifty tow Korean-Chinese women were administere the Questionnaire regarding child-rearing practice and husband-wife relations, with an assumption that Korean-Chinese in Yanbian area would preserve the traditional value in family lief because of the cultureal frozen phenomena. The results of the data for the present study revealed that they keep some traditional child-rearing practice such as the prenatal education and the first-year birthday party. However, the value of boy preference was not widely prevalent in the society. On the other hand the equality in husband-wife relation was not found to be attained even though in Communist society.

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중공 원추형 연료 분무의 미립화 및 벽 충돌 과정에 대한 연구 (A Study on Atomization and Wall Impingement Process of Hollow-Cone Fuel Spray)

  • 심영삼;최경민;김덕줄
    • 한국자동차공학회논문집
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    • 제14권4호
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    • pp.132-138
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    • 2006
  • Numerical analysis about atomization and wall impingement process of hollow-cone fuel spray is performed by a modified KIVA code with hybrid model. The atomization process is modeled by using hybrid breakup model that is composed of Linearized Instability Sheet Atomization(LISA) model and Aerodynamically Progressed Taylor Analogy Breakup(APTAB) model. The Gosman model, which is based on the droplet behaviors after impingement determined by experimental correlations, is used for spray-wall impingement process. The LIEF technique was used to compare the results with those of experiment. The calculations and experiments are carried out at the ambient pressures of 0.1 MPa and 0.5 MPa and the ambient temperature of 293K. It was found that the calculated results show satisfactory agreement with experimental ones.

한국산 노래기류의 분류 및 생태 1. 계림갈퀴노래기 ( Anaulaciulus Koreanus koreanus ( Verhoeff )) 의 생활사와 개체군 동태 (Bionomics and Systematics of Diplopoda in Korea I. The Life-ycle and Population Dynamics of Anaulaiulus koreanus koreanus (Verhoeff) (Diplopoda Julidae))

  • Kim, Tae-Heung;Kil-Young Lim
    • The Korean Journal of Ecology
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    • 제16권2호
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    • pp.155-157
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    • 1993
  • The life-cycle and seasonal abundance of Anaulaciulus koreanus koreanus was studied at Hwang-dong, Chonbuk Province, Korea from October 1990 to February 1992. The egg hatches in spring and the pupoid stage is passed through within the egg shell. The juvenile develops as far as stadium IX by the third year following the birth. Pairing and oviposition take place in the fourth year spring when females are at stadium XI. They seem to live one or two years more after egg-laying. Anamorphosis was observed in this species. Abundance of A. koreanus koreSanus increases from April to May when there appears thefirst peak. It fals gradualy thereafter and the species spends summer months underground from July to September. The second peak appears in October and the activity decreases again in November getting ready to overwinter. The first peak arises from a large number of individuals of 2 and 3 year old overwintered plus newly hatched spring juveniles, and the second from 1 to 3 years old wanderings. Inactivity observed in the species during summer and winter seasons appears to be a temporal due to the extreme temperatures.

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Modifying Action of Chitosan Oligosaccharide on 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)-induced Mutagenesis

  • Shon, Yun-Hee;Ha, Young-Min;Jeong, Teuk-Rae;Kim, Cheorl-Ho;Nam, Kyung-Soo
    • BMB Reports
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    • 제34권1호
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    • pp.90-94
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    • 2001
  • The mutagenic activity of chitosan oligosaccharide and its antimutagenic effect against 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) were investigated using the Salmonella/Ames test. No mutagenic activity was found in the Salmonella typhimurium strains TA 98 and TA 100, either with or without S9 activation. In contrast, chitosan oligosaccharide showed an inhibitory effect on the mutagenic activity of the cooked food mutagen, MeIQx, in the presence of S9. The influence of chitosan oligosaccharide on the genotoxicity of MeIQx was examined using a host-mediated assay in mice. The oligosaccharide was administered for 14 consecutive days (intragastric application at doses of 0.1 or 0.5 g/kg body wt) to mice. S. typhimurium TA 98 was given intravenously before an oral dose of MeIQx (4.5 mg/kg body wt.). The number of $his^+$ revertants were determined from the Ever of mice. The intragastric application of oligosaccharide led to a 47% reduction in the number of mutants induced by MeIQx (p<0.05). These results suggested that chitosan oligosaccharide had antimutagenic properties against MeIQx in vitro and in vivo.

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Effects of Piston Shapes and Intake Flow on the Behavior of Fuel Mixtures in a GDI Engine

  • Kang, Jeong-Jung;Kim, Duck-Jool
    • Journal of Mechanical Science and Technology
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    • 제17권12호
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    • pp.2027-2033
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    • 2003
  • The purpose of this study is to investigate the stratification of fuel vapor with different in-cylinder flow, piston cavity and injection timings in an optically accessible engine. Three different piston shapes that are F(Flat), B(Bowl) and R(Re-entrance) types were used. The images of liquid and vapor fuel were captured under the motoring condition using Laser Induced Exciplex Fluorescence technique. As a result, at early injection timing of 270 BTDC, liquid fuel was evaporated faster by tumble flow than swirl flow, where most of fuel vapor were transported by tumble flow to the lower region and both sides of cylinder for the F-type piston. At late injection timing of 90 BTDC, tumble flow appears to be moving the fuel vapor to the intake side of the cylinder, while swirl flow convects the fuel vapor to the exhaust side. The concentration of mixture in the center region was highest in the B-type piston, while fuel vapor was transported to the exhaust side by swirl flow in F and R-type pistons. At the injection timing of 60 BTDC, the R-type piston was better for stratification due to a relatively smaller bowl diameter than the others.

A Study on the Behavior of Evaporating Diesel Spray Using LIEF Measurement and KIVA Code

  • Yeom, Jeong-Kuk;Chung, Sung-Sik;Ha, Jong-Yul;Kim, Yong-Rae;Min, Kyoung-Doug
    • Journal of Mechanical Science and Technology
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    • 제18권12호
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    • pp.2310-2318
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    • 2004
  • The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 400 bar to 800 bar by using a common rail injection system. Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

벽면 캐비티 각에 따른 GDI 분무의 벽 충돌 과정에 대한 수치적 연구 (Numerical Study on Wall Impingement Process of GDI Spray According to Wall Cavity Angle)

  • 심영삼;김덕줄;최경민
    • 대한기계학회논문집B
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    • 제31권12호
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    • pp.971-978
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    • 2007
  • A spray-wall impingement process of a hollow-cone fuel spray from the high-pressure swirl injector in the Gasoline Direct Injection (GDI) engine were experimented and calculated at various wall geometries. The Linearized Instability Sheet Atomization (LISA) & the Aerodynamically Progressed Taylor Analogy Breakup (APTAB) model and the Gosman model were applied to model the breakup and the wall impingement process of the hollow-cone fuel spray. The numerical modelings were implemented in the modified KIVA code. The calculation results of spray characteristics, such as a spray development process and a radial distance after wall impingement, compared with the experimental results by the Laser Induced Exciplex Fluorescence (LIEF) technique. The droplet size distribution and the ambient gas velocity field, which are generally difficult to obtain by the experimental methods, were also calculated and discussed. It was found that the radial distance after wall impingement and Sauter Mean Diameter (SMD) decreased with increasing a cavity angle.

Opcode와 IAT를 활용한 PE 파일 악성코드 탐지 (PE file malware detection using opcode and IAT)

  • 이정훈;강아름
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2023년도 제67차 동계학술대회논문집 31권1호
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    • pp.103-106
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    • 2023
  • 코로나 팬데믹 사태로 인해 업무환경이 재택근무를 하는 환경으로 바뀌고 악성코드의 변종 또한 빠르게 발전하고 있다. 악성코드를 분석하고 백신 프로그램을 만들면 새로운 변종 악성코드가 생기고 변종에 대한 백신프로그램이 만들어 질 때까지 변종된 악성코드는 사용자에게 위협이 된다. 본 연구에서는 머신러닝 알고리즘을 사용하여 악성파일 여부를 예측하는 방법을 제시하였다. 일반적인 악성코드의 구조를 갖는 Portable Executable 구조 파일을 파이썬의 LIEF 라이브러리를 사용하여 Certificate, Imports, Opcode 등 3가지 feature에 대해 정적분석을 하였다. 학습 데이터로는 정상파일 320개와 악성파일 530개를 사용하였다. Certificate는 hasSignature(디지털 서명정보), isValidcertificate(디지털 서명의 유효성), isNotExpired(인증서의 유효성)의 feature set을 사용하고, Imports는 Import Address Table의 function 빈도수를 비교하여 feature set을 구축하였다. Opcode는 tri-gram으로 추출하여 빈도수를 비교하여 feature set을 구축하였다. 테스트 데이터로는 정상파일 360개 악성파일 610개를 사용하였으며 Feature set을 사용하여 random forest, decision tree, bagging, adaboost 등 4가지 머신러닝 알고리즘을 대상으로 성능을 비교하였고, bagging 알고리즘에서 약 0.98의 정확도를 보였다.

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중국 소수민족의 복식 연구(1) (The costume culture of China is as old and varied as her long history)

  • 박춘순
    • 복식
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    • 제26권
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    • pp.175-206
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    • 1995
  • The costume culture of China is as old and varied as her long history. As China is a multiracial nation and consists of fifty-six min-ority races including Han race, there are not only fifty-six different costumes in China but each races' costume habit is very different. Therefore, Chinese penninsula can be considered an enor-mous exhibition center of the costumes. This study undertook on the assumption that the costumes' mainstream of Korea and east-northern Asia as well as that of China could be examined by investigating the minority races' costumes in the east-and west-northern areas of China. The process of evolution of the costume of a particular people, country or area is subject not only to constraints related to geography such as climate, topography or local products but is also affected by numorous environmental influences including cultural, economic, social and even pol-itical ones in terms of the selection of material, styling, color and standard of tailoring. In other words, things like philosophy of life, religious be-lief, aesthetic outlook, moral code, class system, degree of affluence, and cultural exchange will all be reflected directly or indirectly by features of a people's or country's style costume. Of course, there are several factors affecting to the style of costume of the minority people in China. However, the only three factors-geo-graphical and environmental, production method, and religious belef-will be touched in this study. First of all, the geograghical and eenviron-mental factor would be the decisive one because the costume should be designed to overcome the constraints of climate and geographical environ-ments. Accordingly, each race has an unique style of costume. The costume of the minority races in the northern parts are loose and wide, and made of warm furs. For instance, Mongolian robe has the quality of anti-wind, anti-cold and warmness, and the width of a sleeve is narrow and long. Secondly, the costume style can be said to be limited by the production pattern, when the geo-graphical environment was affected to decide the costume style, the production pattern was together affected to it . In case of Mongolian robe, they should satisfy the dual condition as the practical function. One is the condition that they should be fitted to the climate, and the other is the condition that they should be suit-able to the nomadic life. Mongolian robes are suitable to the nomadic peoples because they are designed for not only overcoming the cold wind and weather but being used as the bedquit at night. The costumes of Hoche people was made of the skin of the fish and wild animals because of their main means of living being fishing and hunting. Accordingly, their costumes are dur-able, warm and water-proof. Finally, the style of the costume is affected by the religious belief. In other words, the pattern in fashion is closely related with the religious be-lief or ancestor worship and nature worship. Ac-cordingly, the symbols of these worship are often emerged in the decoration of the costume. The design of costume of the people in the northern areas of China is very simple. It is related with their monotheism. On the other hand, the costumes of twen쇼 minority races in the east-northern parts of China can be devided into three racial groups such as the long robes of Man people and Mongols, Tunics of the peoples in the west-northern areas, and the pants and jackets of Hoche people. The minorority races all has not only the unique costume habit but their costumes are also related with their living style and production means.

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남녀 중학생의 성에 대한 지식, 태도, 성교육요구도에 관한 연구 - 광주 시내 일부 중학교 1학년 대상으로- (A Survey of Sexual Knowledge, Attitude, Need of Sex Education of schoolchildren - Junior high school St grade students in Kwang-Ju city -)

  • 박인혜;한유정;윤현숙
    • 한국학교보건학회지
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    • 제9권1호
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    • pp.99-108
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    • 1996
  • The purpose of the survey was to identify the degree and the relationship of sexual knowledge, sexual attitude and need of sex education. This information will provide useful data for a more systematic. desirable, and practical sex education. The data was collected from 300 first grade schoolchildren (150 boys and 150 girls) of two Junior high school in K city. The data was gathered by questionnaire from Nov.21 to 28, 1995. The questionnaire was modified by authors using the questionnaire developed by Lief & Reed. Data was analyzed by using the statistical computer package, SAS to manipulate the data along with percentages, means, standard deviation, t-test, $X^2$-test, GLM, and Pearson correlation coeffiency. The results in this study were summarized as follows: 1. Sexual knowledge. - The mean score of sexual knowledges showed no significant differences between boys and girls(p<0.6180), but in the areas of biological differences(boys; $11.57{\pm}2.43$, girls; $10.93{\pm}2.41$, p<0.0242), and pregnancy physiology(boys; $9.28{\pm}1.87$, girls; $10.04{\pm}2.42$, p<0.0026) showed significant difference between boys and girls. 2. Sexual attitudes. - The mean score of sexual attitudes showed no significant difference between boys and girls (p<0.8286), but in the areas of masturbation (boys : $6.69{\pm}2.22$, girls : $5.65{\pm}1.88$, p<0.0001), and premarital intercourse (boys : $5,42{\pm}1.35$, girls : $6.00{\pm}1.33$, p<0.0002) showed significant difference between boys and girls 3. Need of sex education. - The majority of the subjects wanted to learn about sexual delinquency and it's prevention(57.7%), form a friendship with the other sex(56.3%), physical differences of the other sex(52.0%), psychological differences and the charateriatics of the other sex (50.3%) and meaning of love(50.3%). 4. The relationships between sexual knowledges and sexual attitudes. - Those who had higher sexual knowledges showed more positive attitudes towards sex, and showed statistical significance(r=0.2074, p<0.0003). 5. The relationships between general charateristics and sexual knowledge. - Better students(by self-perception of school performance) had higher knowledge scores about sex. 6. The relationships between general charateristics and sexual attitudes. - Those who wanted to learn more about sex, and better students had higher attitude scores about sex. - Those who were in high standard of living had higher attitude scores about sex as well. Suggestions based on above study are as follows' 1. The planned sex education showed be performed to the schoolchildren establish responsible attitudes about sex. 2. Systematic sex education through formal school education according to age is recommended. 3. Further studies should be done to measure the effect of sex education based on the needs of the schoolchildren.

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