• Korean Journal of Mathematics
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• 제19권4호
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• pp.453-464
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• 2011

We used SAS program in statistics class as a plan to increase effect of class. Because lease cost of SAS program is high and low-level students felt difficulty of the syntax of SAS program, I planned to introduce other instruction-software. We observe whether it's O.K. to use Excel instead of SAS program and Excel is helpful in having positive attitudes. We try to compare and analyze the merits of two programs. The purpose of this study is to apply Excel to statistics class, cut down the cost of instruction-software, and make students understand statistics more conveniently and easily.

• 대한미생물학회지
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• 제11권1호
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• pp.27-32
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• 1976

Sodium amylosulfate(SAS) has been reported to be an effective substance to inactivate the anti-bacterial activity of blood in blood culture media. The advantage of the use of SAS over sodium polyanethol sulfonate(SPS) is that it does not inhibit the growth of some bacteria! species which are known to be inhibited by SPS. As to S. typhi, SPS is reported to enhance the growth, however the effect of SAS on this organism is not known as yet. Using 43 strains of S. typhi, isolated from clinical materials, the authors tried to determine the effect of SAS on this organism. The methods used for this study were : the SPS and SAS paper disk I sensitivity test, tests on the growth in trypticase soy broth(TSB) with SPS and with SAS, and experimental blood culture in SPS and SAS incorporated TSB. The following results were obtined. 1). S. typhi strains with the turbidity of No. 0.5 tube of MacFarland nepherometer were inoculated onto Mueller-Hinton plate and 1mg disk of SPS and SAS were applied. After 24-hour incubation, none of the 43 strains showed inhibition zone by SPS disk, but all of them showed zones by SAS disk with a mean zone diameter of 9.5mm(Table 1). 2) Inocula consisting of one to 54 viable counts of 37 strains were inoculated into three different media; TSB with 0.05% SPS, TSB with 0.05% SAS and TSB alone. After 24-hour incubation the mean of the optical densities of each medium were 0.483, 0.482 and 0.459 respectively, showing that SAS does not inhibit the growth of S. typhi. Moreover it was shown that there was no correlation between the amount of inocula and growth(Table 2 and Fig. 1). 3). Each set of media in 5 ml amounts consisting of one tube of TSB with 0.05% SPS, one tube of TSB with 0.05% SAS and two tubes of TSB were inoculated with 8, 64. 640 and 6400 viable counts of bacteria. Then 0.5 ml of fresh normal blood was added to all tubes except for one tube of TSB. Macroscopic observation after 24 hour incubation showed a heavy growth in all tubes except for the tube of TSB plus blood, which showed only a light growth in the tube of the heaviest inoculum. This result clearly demonstrates that the growth of S. typhi is inhibited by some antibacterial activities of fresh blood, which are counter acted by SPS and SAS(Table 3). Between SPS and SAS, there was no significant difference found(Table 4 and Fig. 2). With all these results it can be postulated that the addition of SAS into a rountine blood culture media may raise the positivity of S. typhi isolation and shorten the incubation period.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.197.2-197
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• 2002

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1647-1650
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• 2003

The Objective of this work was to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that was asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSFIP elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was 16${\times}$8 array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue lift curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75(1.875kN) load level. SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.108-111
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• 2003

The Objective of this work was to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that was asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSFIP elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was $16\;{\times}\;8$ array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75(1.875kN) load level. SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.

• Korean Journal of Mathematics
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• 제16권4호
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• pp.471-480
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• 2008

As students with low basic knowledge of mathematics increase, they have had difficulties in studying statistics theory class. By using recent students' characteristics which prefer seeing directly and checking to thinking logically, we try to change the teaching method into teaching in the computer lab(SAS program). We investigate whether changing the teaching method has effects on students' achievements and interests or not. The purpose of this study is to grope for a better teaching and develop mathematics education's satisfaction and qualification.

• 전기학회논문지P
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• 제64권4호
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• pp.281-285
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• 2015

Electrical energy supply interruption degrades reliability of power supply as well as social costs and economic loss. It is important to assess the reliability of the power system. Nowadays IEC61850 based substation automation system(SAS) has been developed for an updating of automation and interoperability. In this study, three kinds of reliability block diagram(RBD) were proposed to examine of network availability of the three types SAS. And reliability and unreliability of the SAS was formulated using the RBD. Finally, while varying the value of reliability and unreliability, the reliability and the unreliability of the overall system were evaluated.

• 대한전자공학회논문지SP
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• 제38권4호
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• pp.335-343
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• 2001

기존의 웨이브릿 기반 프랙탈 압축 방법은 전 영역에 대하여 최적의 정의역을 탐색하므로, 부호화 과정에서 많은 탐색시간이 소요되는 단점이 있다. 그래서 본 논문에서는 웨이브릿 변환영역에서 SAS(Self Affine System) 기법과 다중 스케일 인자를 이용한 웨이브릿 변환 기반 프랙탈 영상 압축 방법을 제안한다. 웨이브릿 기반 영역에서 정의역과 치역을 구성하고, 각각의 치역 블럭에 대해 모든 정의역 블럭을 탐색하는 것이 아니라, 정의역 탐색과정이 필요 없는 SAS 기법을 도입하여 공간적으로 같은 위치에 있는 상위 레벨 블록을 정의역으로 선택한다 그래서 부호화 과정에서 곱셈 계산량을 감소시켜 고속 부호화를 가능하게 한다. 그리고 SAS 기법의 단점인 화질이 떨어지는 단점을 개선하기 위해, 각 레벨별로 서로 다른 스케일 인자를 사 용하여 화질을 개선한다. 그 결과 화질에는 영향을 미치지 않고 부호화 시간과 압축률이 개선되고, 점진적 전송이 가능한 알고리듬을 제안한다.

• Advanced Composite Materials
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• 제17권3호
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• pp.215-224
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• 2008

The present study aims to design a multilayer microstrip antenna with composite sandwich construction and investigate fatigue behavior of this multilayer SAS (surface antenna structure) that was asymmetric sandwich structure for the next generation of structural surface technology. This term, SAS, indicates that the structural surface becomes an antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, antenna elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.2 GHz. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of the SAS was obtained. The experimental results of bending fatigue were compared with single load level fatigue life prediction equations and in good agreement. The SAS concept is can be extended to give a useful guide for manufacturers of structural body panels as well as antenna designers.

• Advances in biomechanics and applications
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• 제1권4호
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• pp.253-267
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• 2014

The human head is identified as the body region most frequently involved in life-threatening injuries. Extensive research based on experimental, analytical and numerical methods has sought to quantify the response of the human head to blunt impact in an attempt to explain the likely injury process. Blunt head impact arising from vehicular collisions, sporting injuries, and falls leads to relative motion between the brain and skull and an increase in contact and shear stresses in the meningeal region, thereby leading to traumatic brain injuries. In this paper the properties and material modeling of the subarachnoid space (SAS) as it relates to Traumatic Brain Injuries (TBI) is investigated. This was accomplished using a simplified local model and a validated 3D finite element model. First the material modeling of the trabeculae in the Subarachnoid Space (SAS) was investigated and validated, then the validated material property was used in a 3D head model. In addition, the strain in the brain due to an impact was investigated. From this work it was determined that the material property of the SAS is approximately E = 1150 Pa and that the strain in the brain, and thus the severity of TBI, is proportional to the applied impact velocity and is approximately a quadratic function. This study reveals that the choice of material behavior and properties of the SAS are significant factors in determining the strain in the brain and therefore the understanding of different types of head/brain injuries.