• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.39-41
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• 2004

This paper demonstrates the in-house development of the subsystem C&DH in a D-SAT satellite project of Astronautic Technology (M) Sdn. Bhd. (ATSB). D-SAT is a non-imaging satellite. It will carry a dosimeter as the payload for scientific objectives. Since one of the D-SAT project establishment intended objectives is to demonstrate the research and development skill of the ATSB engineers on the satellite system building, most of the subsystems of the D-SAT are developed in-house including the C&DH subsystem. C&DH subsystem plays an important role for managing data handling tasks and general operation of the satellite system. The C&DH development includes the research and study on the hardware and software design, the design of both the hardware and software, the development of the software system, the integration between the software and the hardware system and the implementation of the subsystem into the satellite system. This program allows ATSB to accomplish the engineers with expertise not only in the C&DH subsystem but other subsystems too besides developing knowledge in the management of a space project that covers not only on the technical issues but issues relating to the economic, political and legal issues.

• 대한간호학회지
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• 제31권5호
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• pp.835-845
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• 2001

This study was to identify the relationship between personality type, college admission SAT scores and GPA scores of student nurses. Method: The data was collected from 270 student nurses enrolled in a baccaleaureate program in Seoul. MBTI was used to identify students' personality and SAT score and GPA score were collected over 4 years. The collected data was analyzed by using SPSS Win. package. Result: 1. There were slightly more extrovert (E) type (54.4%) students than the introvert (I) type; more sensing (S) type (71.1%) than the intuitive (N) type. 2. The introvert type students had significantly higher SAT scores than those of the extrovert type (p=.002). 3. The judging type students had significantly higher GPA scores throughout their college years than the perceiving type. 4. There was no statistically significant relationship between SAT and GPA scores. SAT scores did not accurately predict students' academic achievement in college in this sample. Conclusion: The distribution of the personality types in the sample was different from the general population which may suggest that college admission criteria is biased toward certain personality type. Since different personality types process information and cope with the outside world differently, effective teaching strategies need to be considered for each class.

• 대기
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• 제25권3호
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• pp.461-472
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• 2015

The sudden stratospheric warming (SSW), which is characterized by an abrupt increase of polar stratospheric temperature by several tens of degrees in a week, has been known to affect tropospheric weather and climate on sub-seasonal time scale in the boreal winter. Such downward coupling has been often examined in North Atlantic and Europe, but rarely examined in East Asia. In this study, by applying the two definitions of SSW to the reanalysis data, the possible impacts of the SSW events on the surface air temperature (SAT) and tropospheric circulation in East Asia are analyzed. It is found that Eurasian continent, including Siberia and the Northeast Asia, tends to experience anomalously cold SAT for up to sixty days after the SSW events. The resulting SAT anomalies largely resemble those associated with negative Artic Oscillation. However, over East Asia, SSW-related SAT change is weak and not statistically significant. Only during the extreme SSW events when the downward coupling between the stratosphere and troposphere is strong, East Asia exhibits significantly cold SAT anomalies. This relationship is presented by grouping SSW events into those followed by cold SAT anomalies over East Asia and those by warm anomalies for varying threshold values of the SSW events.

• 동력기계공학회지
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• 제17권2호
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• pp.21-28
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• 2013

Phenomenon of droplet impingement with high temperature wall needs to be investigated because atomization process of droplet and cooling process of the wall by the impingement are very important in industry, thus studies concerned with temperature of piston wall have been conducted in spray characteristics analysis of diesel engine. Hence, in this study, we defined $DT_{sat}(=T_w-T_{sat})$ superheat degree of the wall by difference between $T_w$ considering surface temperature of piston in the actual engine and $T_{sat}$ saturation temperature of the fuel and then investigated spray behavior of wall impinging with variance of the boiling process. In this study, in order to analyze wall impingement of droplet in accordance with difference of boiling condition, calculational conditions were set as $DT_{sat}=40K$(nucleate boiling), $DT_{sat}=140K$(transition boiling), and $DT_{sat}=240K$(film boiling). As a result, it can be found that fuel vapor increases and droplet mass decreases in the order of the nucleate boiling, transition boiling, and film boiling.

• Journal of Astronomy and Space Sciences
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• 제32권3호
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• pp.257-268
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• 2015

Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

• 인터넷정보학회논문지
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• 제9권2호
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• pp.89-105
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• 2008

지금까지 테스트 데이터를 자동으로 생성하기 위한 대부분의 연구는 프로그램에 포인터가 존재하지 않는 경우만을 대상으로 하였다. 최근에 포인터가 있는 경우에도 테스트 데이터를 자동으로 생성할 수 있는 방법들이 제안되었지만 테스트할 프로그램 경로를 완전하게 명시해야 하는 경로 기반 방법이거나 프로그램을 실제 실행해야 하는 방법들이다. 이 논문에서는 프로그램 경로를 완전하게 명시하지 않아도 포인터가 있는 프로그램에 대하여 테스트 데이터를 생성할 수 있는 새로운 방법을 제안한다. 제안된 방법은 테스트 데이터 생성 문제를SAT(SATisfiability) 문제로 변환하고 SAT 해결도구를 이용하여 자동으로 테스트 데이터를 생성하는 정적 방법이다. 이를 위해 프로그램을 1차 관계 논리 언어인 Alloy로 변환하고 Alloy 분석기를 통하여 테스트 데이터를 생성한다.

• 대한산업공학회지
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• 제30권1호
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• pp.17-26
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• 2004

In this study, the usability evaluation of a menu-structure was performed using spreading activation model with respect to human's memory retrieval. Spreading Activation Model is effectively used to understand the process of information retrieval, so it can be used as a theoretical background for modeling of the process of human's information retrieval. For spreading activation test (SAT), subjects were presented with 67 pairs of menu titles, which consist of a menu title in the high level menu item and a menu title for the next lower level menu item, from Korea University's web site. For performance tests, three scenarios were developed with longer reaction times and ambiguous associations found in the SAT to reflect the existing problems of the website. As a result, the SAT was found to bean effective tool to enhance the website usability because the SAT could bea substitute for the performance test with a high correlation $({\rho}=0.735,\;{\alpha}=0.05)$. After remaining menu titles with slow reaction times and ambiguous associations found in SAT, the website usability was significantly improved with faster reaction times and less ambiguous associations proven with smaller number of web-page visits. Therefore, the SAT could be used as a methodology to design and evaluate the user-centered menu structure related to human's association structure.

• 정보처리학회논문지D
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• 제16D권3호
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• pp.371-380
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• 2009

최근에 테스트 데이터를 자동으로 생성하는 방법에 관한 연구가 활발하게 진행되고 있다. 그러나 이러한 방법들은 플래그 변수가 프로그램에 존재하는 경우에는 효과적이지 못함이 밝혀졌다. 이는 엔진 제어기와 같은 내장형 시스템들이 전형적으로 디바이스 관련 상태 정보를 기록하기 위해 플래그 변수를 많이 이용한다는 점을 고려할 때 문제가 된다. 이 논문에서는 플래그 변수가 있는 프로그램에 대하여 효과적으로 테스트 데이터를 생성할 수 있는 방법을 소개한다. 이 방법은 테스트 데이터 생성 문제를 SAT(SATisfiability) 문제로 변환하고 SAT 해결도구를 이용하여 자동으로 테스트 데이터를 생성한다. 이를 위해 프로그램을 1차 관계 논리 언어인 Alloy로 변환하고 Alloy 분석기를 통하여 테스트 데이터를 생성한다.

• Applied Biological Chemistry
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• 제38권4호
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• pp.320-324
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• 1995

쥐 뇌의 microsome으로 부터 ${\Delta}^{5}-3{\beta}$-hydroxy steroid acyl 전이효소(${\Delta}^{5}-3{\beta}$-OH-SAT)를 detergent를 이용하여 용해한 뒤에 인산지방질 liposome에서 재구성하여 처리하지 않은 microsome의 ${\Delta}^{5}-3{\beta}$-OH-SAT의 활성도와 비교하였다. 용해에 사용한 detergent중에는 deoxycholic acid가 Tween 80이나 Triton X-100 보다 우수한 ${\Delta}^{5}-3{\beta}$-OH-SAT 활성도를 나타냈으며, liposome 생성에 사용한 인산지방질중에서는 난황 및 대두 phosphatidyl-choline이 가장 높은 활성도를 보였으며 그 다음이 phosphatidylethanolamine이었고 phosphatidylserine과 phosphatidic acid는 재구성하지 않은 용해된 효소보다 ${\Delta}^{5}-3{\beta}$-OH-SAT 활성도가 낮았다. 따라서 인산지방질의 head group의 4차 암모늄기나 amine기는 ${\Delta}^{5}-3{\beta}$-OH-SAT의 재구성활성을 촉진시키고 COOH기가 amine기와 함께 존재하거나 amine기가 없으면 이 효소의 활성이 저해됨을 알 수 있었다.

• 한국항공우주학회지
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• 제45권2호
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• pp.154-162
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• 2017

인공위성의 시스템 설계 및 운용에 대한 이해증진을 목적으로 국내에서는 2012년을 시작으로 매년 캔위성 경연대회가 개최되고 있다. 본 논문에서 제안한 캔위성은 2016년 경연대회에 출전한 SCSky(Smart Call from the Sky) CanSat으로, 주요임무는 캔위성에 탑재된 스마트폰을 이용하여 영상통화 연결을 통해 위성체 내 외부 및 비행영상 획득을 목표로 하고 있으며, 임무 구현을 위해 형상기억합금 와이어를 적용한 원격터치시스템을 개발하였다. 아울러 부가적인 임무로 비행 임무동안 보다 넓은 범위의 지상관측영상 획득을 목적으로 형상기억합금스프링을 적용한 광역스캔카메라 메커니즘을 개발하였다. 본 논문에서는 상기 캔위성에 대한 임무를 비롯해 개발 탑재체 및 캔위성 시스템 소개, 최종 비행시험결과에 대하여 서술하였다.