• Title/Summary/Keyword: BIG4

Search Result 3,614, Processing Time 0.034 seconds

Far Feild test on Electromagnetic Wave Absorber in Paint Type for X-babd Radar (X-Band Radar용 도료형 전파흡수체의 실장실험)

  • 안영섭;김동일;정세모
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.4 no.3
    • /
    • pp.3-10
    • /
    • 1993
  • As a method to measure the absorbing characteristics of microwave absorber, various microwave measuring method can be used fundamentally. There is, however, a big problem in measuring errors, since the wavelength of microwave such as used for radar is very short. Therefor, this research aimed to design and fabricate a converting adaptor of 20mm .PHI. coaxial tube from a type-N connector to coaxial tube and to use it for evaluating absorption characteristics of microwave absorbor. Furthemore, the measurements of absorbing characteristics and material constants have been perfomed and reviewed, which were carried out by using the coaxial and by using rectangular waveguide, respectively. As a result, the validity of the proposed measuring method has been conformed. In this paper, a preliminary evalua- tion on the characteristics of the electromagnetic wave absorbor for X-band radar designed and fabricated for a laboratory use is performed by reflected power method near to a pratical use. Then for field test by using X-band radar is carried out with real target of $1.2m\times1.2m$ in size. As the result of the above, the usefullness of the designed and fabricated electromagnetic wave absorber in paint type for X-band radar has been confirmed.

  • PDF

Exploiting an On/off-Chip Bus Bridge for an Efficiently Testable SoC (효율적인 SoC 테스트를 위한 온/오프-칩 버스 브리지 활용기술에 대한 연구)

  • Song, Jae-Hoon;Han, Ju-Hee;Kim, Byeong-Jin;Jeong, Hye-Ran;Park, Sung-Ju
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.45 no.4
    • /
    • pp.105-116
    • /
    • 2008
  • Today's System-on-a-Chip (SoC) is designed with reusable IP cores to meet short time-to-market requirements. However, the increasing cost of testing becomes a big burden in manufacturing a highly integrated SoC. In this paper, we propose an efficient test access mechanism that exploits an on/off-chip bus bridge for the Advanced High-performance Bus (AHB) and Peripheral Component Interconnect (PCI) bus. The test application time is considerably reduced by providing dedicated test stimuli input paths and response output paths, and by excluding the bus direction tumaround delays. Experimental results show that area overhead and testing times are considerably reduced in both functional and structural test modes. The proposed technique can be a lied to the other types of on/off-chip bus bridges.

Community Health Education (지역사회 보건교육)

  • Lee, Ju-Yul;Park, Chun-Man;Suh, Mee-Kyung;Choi, Eun-Jin
    • Korean Journal of Health Education and Promotion
    • /
    • v.24 no.4
    • /
    • pp.241-249
    • /
    • 2007
  • Health education aims at behavior change rather than just delivering health knowledge to people. In Korea health education activities in public sector began in 1960 and they were included in the primary prevention program in communities. This article reviewed current health education programs in healthy living practice programs provided by local public health centers in Korea and drew implications for the future role of health education in community setting. Health education has been a core function of the National Health Promotion programs in the nation since the enactment of the National Health Promotion Law in 1995. The National Health Promotion programs are funded by the National Health Promotion Fund which are drawn from tobacco tax. The National Health Promotion programs include healthy living practice programs (smoking prevention and cessation programs, moderate alcohol use programs, physical activity promotion programs, and nutrition programs), chronic disease prevention programs, oral health programs and public hygiene programs. Methods of the National Health Promotion programs include health education, health counseling, health class, health information management, survey and research. Smoking prevention and cessation programs include smoking cessation clinic, smoking cessation education, non-smoking environment program, and non-smoking campaign. Moderate alcohol use programs include alcohol use education, moderate alcohol use campaign, alcohol use counseling, and alcohol free environment programs. Physical activity promotion programs include obesity control, targeted exercise program, and exercise civic group programs. Nutrition programs include nutrition management, obesity management, nutrition education, breakfast eating program, and nutrition counseling and treatment programs. The health education programs in community are not efficient today because there are many overlapping contents and short term goals. Community health education programs needs to be more comprehensive. Workforce development is another big issue at the moment because the National credential program will begin in 2009. Variety of community health education programs should be developed and funded by the national health promotion fund.

Prediction of Old-Growth Development in Second-Growth Hardwood Forests using Computer Simulation (Computer Simulation을 이용(利用)한 이차활엽수림(二次闊葉樹林)의 노숙림(老熟林) 발달예측(發達豫測))

  • Choi, Jung-Kee
    • Journal of Korean Society of Forest Science
    • /
    • v.89 no.4
    • /
    • pp.502-512
    • /
    • 2000
  • Old-growth development for two different second-growth northern hardwood stands in the North America was evaluated with a computer simulation. The two sites compared were a representative 77 year old even-aged stand (Phelps) with heavy dominance by pole size classes, and an older uneven-aged stand with some existing old-growth structural features (Wildcat Creek). Each stand was evaluated in its natural progress toward old-growth structural conditions with stand structure, size distribution of live and dead trees, percent stand area in canopy gaps, and visual canopy profile and overhead view. The Phelps stand reached the minimum structural threshold for the old-growth stage after 74 years. Only 13 years was required for Wildcat Creek stand to reach the old-growth threshold. During the 45 years of simulation, the diameter distributions of both stands became broader and flatter. DBH distribution of dead trees had a general descending trend over the simulation in each stand. Gaps at Phelps were typically small after 45 years. Gap area at Wildcat Creek was somewhat more constant over the 45 years of simulation but a big gap was formed because of the death of several adjacent large trees.

  • PDF

A study on the Patterns of ART NOUVEAU Silhouette by Draping Design (입체재단법에 의한 ART NOUVEAU 의상 SILHOUETTE의 PATTERN 연구)

  • 정흥숙
    • Journal of the Korean Society of Costume
    • /
    • v.50
    • /
    • pp.5-22
    • /
    • 2000
  • The study on the past costume should be done first for the creation of new style of fashion. That is one of the reasons why we have to annalize characteristic style in each period. Before the latter of nineteenth century one must have made the costume by draping design. Because the complicated clothes can be expressed by draping deign think that the subject draping design is even more important than other subject. But there haven't been the studies that analyzed the pattern of Art Nouveau style by draping design in Korea. Art Nouveau style is a certain one that was relatively more changeable than the ones of other periods. The purpose of this study is the analysis about the patterns of hourglass and S-curve style which represented the Art Nouveau style. The results of the study summarized as follows. 1. Bodice pattern : In the front Hourglass silhouette has the princess line for fitting bodice while S-curve silhouette has the wide midriff due to the blousing. There is the yoke in S-curve one. In the pattern of back bodice we can't see the much differences but Hourglass silhouette is used the princess line like the front one while S-curve is made use of the waist darts for fitting back. 2. Sleeve pattern : Hourglass silhouette is made of two pieces the upper part and lower part besides S-curve is consisted of one pieces. The former has the big upper part in order to the emphasis of the shoulder and the tight lower part. The latter is the tight sleeve that similar to the basic sleeve pattern at present. 3. Skirt pattern: There is partially a gored line in the front skirt in Hourglass silhouette however S-curve silhouette is consisted of the six pieces gored skirt. At this part we can also see the fact that s-curve is more complicated than Hourglass silhouette. 4. Others: Wecan find out the differences between Hourglass and S-curve pattern easily at the parts of the collar flounce wing and so on. Summing up, the patterns of S-curve style are more expanded than those of Hourgalss style for the most part.

  • PDF

A Survey on Wearing of Brassieres according to Body and Breast Type of College Women (20대 여대생의 체형 및 유방유형별 브래지어 착용실태조사 연구)

  • Sohn, Boo-Hyun;Kweon, Soo-Ae
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.36 no.8
    • /
    • pp.791-801
    • /
    • 2012
  • We performed an assessment of wearing, purchasing, satisfaction, and the fit of brassieres according to body and breast type for college women to provide basic data on the manufacture of an ergonomic brassiere. The classifications of domed and conical breast type or projecting and conical breast type were unclear. Flat breast were dissatisfied with the shape of small and flat, and drooping breast were dissatisfied with the shape of big, projected, and drooping. In purchasing a brassiere, the majority of subjects were ignorant of their brassiere size, and over 80% of the subjects bought a brassiere without trying it on. Over 50% of those surveyed said they found it difficult to buy a well-fitted brassiere, particularly for the flat and drooping breast type. Over 70% of those surveyed wore a brassiere of 3/4 cup size, the slim body type wore a brassiere of 1/2 cup size; however, the obese body type wore a brassiere of full-cup size. The flat-breast or slim-body wore a brassiere of a thick pad type but projecting-breast or drooping breast wore brassiere of a thin pad type. Many of the subjects wore an unfitted brassiere in cup size and under bust size. In the classification of breast type, there were slight differences between the breast type that they recognized and the breast type that they were shown. There were distinctions in function, satisfaction, and fitness based on breast type. Therefore, the development of an ergonomic brassiere should considered the characteristics of breast type for fitness and comfort.

Asymmetric Hydrogenation of Ethyl Pyruvate over Bimetallic Rh-Pt/Al2O3 Catalysts Modified with Dihydrocinchonidine (Dihydrocinchonidine으로 개질된 Rh-Pt/Al2O3 이원금속 촉매를 이용한 Ethyl Pyruvate의 비대칭 수소화)

  • Cho, Hong-Baek;Kang, Joon-seok;Park, Yeung-Ho
    • Applied Chemistry for Engineering
    • /
    • v.17 no.4
    • /
    • pp.369-374
    • /
    • 2006
  • $Rh-Pt/Al_{2}O_{3}$ catalysts were used for the first time to study its reaction characteristics in the asymmetric hydrogenation of ethyl pyruvate. The catalysts were prepared either by impregnation of Rh on a commercial $Pt/Al_{2}O_{3}$ or by sequential impregnation of Rh followed by impregnation of Pt on $Al_{2}O_{3}$. Reaction rate and enantiomeric excess (ee%) were compared according to the preparation method, Rh contents, and the reduction temperature of the catalyst. The physical characteristics of the catalysts were analyzed using XRD and TEM. Bimetallic $Rh-Pt/Al_{2}O_{3}$ catalysts showed an improved reaction rate and optical purity (63.6 ee%) with increasing the reduction temperature. The variation of the Rh contents as well as the preparation method elicited a big difference on the reaction rate, while enantiomeric excess (ee%) was lower (56~60%) with all bimetallic catalysts than with monometallic $Pt/Al_{2}O_{3}$ catalyst.

A Study on Correlation Analysis between Library Anxiety and Personality Traits (도서관 불안과 성격 유형의 상관관계 분석 연구)

  • Oh, Eui-Kyung
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.46 no.2
    • /
    • pp.199-217
    • /
    • 2012
  • This study analyzes the correlation between the library anxiety and personality traits. The library anxiety (LAS) and personality traits (the Korean BFI) were measured against 49 freshmen in the university. The library anxiety was average 2.57, 'mechanical barriers' score was the highest(2.91), subsequently was 'affective barriers' 2.72, 'barriers with staff' 2.49, 'knowledge of library' 2.42, and 'comfort with the library' score was the lowest(2.38). The personality traits had the tendency that 'agreeableness'f actor(3.65) is higher than other 4 factors, 'neuroticism'(3.48), 'extraversion'(3.27), 'openness'(2.85), and 'conscientiousness' (3.26). It found that 'comfort with the library' and 'neuroticism' were correlated statistically and the personality traits have an effect on library anxiety. Based on the findings, the following recommendations are made: improving the measurement tool of information anxiety, using other personality traits variables in similar researches, and developing personalized library anxiety resolution programs.

On the Applications of the Genetic Decomposition of Mathematical Concepts -In the Case of $Z_n$ in Abstract Algebra- (수학적 개념의 발생적 분해의 적용에 대하여 -추상대수학에서의 $Z_n$의 경우-)

  • Park Hye Sook;Kim Suh-Ryung;Kim Wan Soon
    • The Mathematical Education
    • /
    • v.44 no.4 s.111
    • /
    • pp.547-563
    • /
    • 2005
  • There have been many papers reporting that the axiomatic approach in Abstract Algebra is a big obstacle to overcome for the students who are not trained to think in an abstract way. Therefore an instructor must seek for ways to help students grasp mathematical concepts in Abstract Algebra and select the ones suitable for students. Mathematics faculty and students generally consider Abstract Algebra in general and quotient groups in particular to be one of the most troublesome undergraduate subjects. For, an individual's knowledge of the concept of group should include an understanding of various mathematical properties and constructions including groups consisting of undefined elements and a binary operation satisfying the axioms. Even if one begins with a very concrete group, the transition from the group to one of its quotient changes the nature of the elements and forces a student to deal with elements that are undefined. In fact, we also have found through running abstract algebra courses for several years that students have considerable difficulty in understanding the concept of quotient groups. Based on the above observation, we explore and analyze the nature of students' knowledge about $Z_n$ that is the set of congruence classes modulo n. Applying the genetic decomposition method, we propose a model to lead students to achieve the correct concept of $Z_n$.

  • PDF

Visual Evaluation of Design Variations in Power Shoulder Jacket (파워 숄더 재킷의 디자인변화에 따른 시각적 평가)

  • Kim, Jeong-Mee;Lee, Jung-Soon
    • Journal of Fashion Business
    • /
    • v.15 no.1
    • /
    • pp.80-91
    • /
    • 2011
  • The purpose of this study is to evaluate the differences of visual effects and visual images by variations in shoulder angle and shoulder width of power shoulder jacket. The stimuli are 5 samples: One control group, 2 variations of the angle of shoulder line and 2 variations of the width of shoulder line. The data has been obtained from 87 fashion design majors. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test and the Correlation Analysis. The results of the study are as follows: The visual images by the angle and the width of shoulder line of power shoulder jacket are composed of 4 factors : attention, stiffness and softness, masculinity, and trendiness. Among these factors, attention factor is estimated by the most important factor. The visual effects by the angle and the width of shoulder line of power shoulder jacket are composed of 3 factors : whole silhouette, neck and arm figure, upper body figure. In these factors, the whole silhouette is estimated by the most important factor. The power shoulder jacket with extreme changes in shoulder angle has double images: it looks trendy and classy but also gives an awkward image. In case of changes in shoulder width, the visual evaluation shows big differences with the degree of expansion. The visual evaluation with variation in angle has stronger image and effect than that in width. The power shoulder jacket trend itself is also evaluated that variation in angle reflects the trend better than that in width.