• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.104.2-104
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• 2001

• Journal of Korean Neurosurgical Society
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• 제67권3호
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• pp.308-314
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• 2024

Vein of Galen aneurysmal malformation is one of important pediatric arteriovenous shunt diseases, especially among neonates and infants. Here, early history of the disease identification, basic pathoanatomy with a focus on the embryonic median prosencephalic vein, classification and differential diagnoses, and recent genetic studies are reviewed.

• 한국지반공학회지:지반
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• 제14권3호
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• pp.95-108
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• 1998

지반의 S파 및 P파의 깊이에 따른 변화를 원위치에서 측정하기 위하여 다운흘 시험 (downhole testing)과 SCPT (seismic CPT) 등이 널리 사용되어 왔다. 다운홀 시험과 SCPT는 경제성, 운용의 용이성, 발진원의 단순성 등의 측면에서 효율적이기 때문에, 현재 지반조사에서 그 사용빈도가 더욱 증가하고 있는 추세이다. 특히 최근에는 다운흘과 SCPT의 자료 분석을 자동화하기 위한 노력의 일환으로 interval measurements의 기법이 활용되고 있는데, 현재 이에 대한 적절한 역산해석 (inversion analysis) 기법이 없는 형편이다. 따라서, 본 논문에서는 다운홀이나 SCPT의 interval measurements를 분석하기 위한 새로운 역산해석 기법을 제안하였다. 제안된 역산해석 기법의 정모델링(forward modeling)에서는 탄성파의 전파를 Snell의 법칙에 의거하여 굴절.반사되는 현상을 고려하였곡, 역산해석을 위해서는 최대공산법 (maximum likelihood method)을 적용하였다. 그리고, 본 논문에서 제안한 역산해석 기법의 검증을 위하여, 하나의 S파 주상도를 가정하고 이에 대하여 다운흘 시험을 모사하였다. 이론적으로 수행한 다운홀 시험 결과에 대하여 기존의 비 역산해석 방법과 본 논문에서 제안한 역산해 석 기법에 의해서 S파 주상도를 추정하였는데, 그 결과 본 논문에서 제시한 역산기법이 가장 정확한 결과를 도출하였으며, 다운홀 시험과 SCPT을 자동화하는데 효율적으로 적용이 될 수 있음을 입증하였다.

• Journal of Information Processing Systems
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• 제7권2호
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• pp.363-384
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• 2011

As the complexity of software is increasing, generating an effective test data has become a necessity. This necessity has increased the demand for techniques that can generate test data effectively. This paper proposes a test data generation technique based on adequacy based testing criteria. Adequacy based testing criteria uses the concept of mutation analysis to check the adequacy of test data. In general, mutation analysis is applied after the test data is generated. But, in this work, we propose a technique that applies mutation analysis at the time of test data generation only, rather than applying it after the test data has been generated. This saves significant amount of time (required to generate adequate test cases) as compared to the latter case as the total time in the latter case is the sum of the time to generate test data and the time to apply mutation analysis to the generated test data. We also use genetic algorithms that explore the complete domain of the program to provide near-global optimum solution. In this paper, we first define and explain the proposed technique. Then we validate the proposed technique using ten real time programs. The proposed technique is compared with path testing technique (that use reliability based testing criteria) for these ten programs. The results show that the adequacy based proposed technique is better than the reliability based path testing technique and there is a significant reduce in number of generated test cases and time taken to generate test cases.

• 대한지구과학교육학회지
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• 제4권2호
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• pp.89-101
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• 2011

Science, Mathematics, Engineering, and Technology (STEM) integrated education has been spotlighted as a new approach for promoting students' conceptual understanding and supporting their future career in STEM field. There is increasing evidence of the positive impact of using a whole design process that can be an example of STEM integrated activities to improve students' conceptual understanding and problem solving skills. However, there is a lack of information on how teachers should accomplish science and engineering integration activities in their classroom and what process they should pay attention. To answer this question, we research the relationship between an design process and students' conceptual understanding using an engineering design activity, called 'Save the Penguins', and study on how each step in an engineering design process in this activity enhance students' conceptual knowledge in science. We found that testing their prototypes and discussing with their peers were the most important process for students to understand and apply science concept for their design, even though the whole engineering design process (demonstration about radiation, discussion about examples in our lives, and testing and reviewing their prototypes, and making final design) helps the students understand the scientific concepts.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.949-952
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• 2005

According to the national space program in Korea, is satellites will be launch into space up to 2015. Especially, KARI is going to develope of its own a high resolution camera of less than 1m to be mounted on next Multipurpose Satellite. When performing testing of large spacecraft or hardware that will be launched into orbit, it is necessary to conduct a testing with space-simulated environment. To achieve this requirement, thermal vacuum chamber is generally used. KARI has been developed a very Large Thermal Vacuum Chamber(LTVC) from 2003 to accomodate future space program, such as KOMPSAT, COMS, and Launch vehicles. This new facility will be used to qualify the first self developed High Resolution Camera, which will be loaded on KOMPSAT-3. To perform an optical test for space camera, it is necessary to provide vibration free environment. Thus the vibration responses on the optical table due to external vibration should be minimized by using a special isolation system. In this paper, we propose the concept design of vibration isolation system for the development of the high resolution camera.

• 한국운동역학회지
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• 제12권2호
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• pp.407-415
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• 2002

Athletic products must meet the needs of athletes and the demands imposed by sports through innovative design. These needs of athletes and requirements of sports are performance, protection and comfort related. In depth knowledge of anatomy and physiology, etiology of commonly reported injuries, and lower extremity mechanics form the basis of product creation/engineering. Game analysis which entails time and frequency surveys of the skills performed during a game, interviews with athletes and coaches, and discussions with medical staffs are used to identify the skills that are critical to the needs of athletes. In lab full biomechanical analyses of these skills and/or physiological responses of the athletes lead to clear functional criterions that serve as guidelines to be met by the design team. The concepts created by the design team are in turns subjected to the same battery of biomechanical analyses. The learning gathered through this pluridisciplinary process is used to further evolve design concepts. The evolution-testing loop is repeated until biomechanical and/or physiological, mechanical and perceptual tests indicate that the design concept meets the established functional design criterions. At that time, the design concepts is ready for manufacturing research and development. Additional biomechanical and physical tests are performed through that phase to confirm that the manufacturing processes preserve the functionality of the design concept. Durability and long term performance of production samples are evaluated through a final three month long weartest program. A rigorous research/testing program is crucial to create and engineer sport products that meet the performance, protection.

• 비파괴검사학회지
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• 제34권5호
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• pp.390-396
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• 2014

본 연구에서는 압전소자를 이용한 철도차량용 스마트 좌석 기술에 대한 적용성을 검토하였다. 이를 위해 스마트 좌석 기술에 대한 개념을 정립하였고, 실제 철도차량용 좌석을 단순화한 축소 모형을 제작하여 압전소자를 적용한 후 스마트 좌석의 기능에 대한 시뮬레이션 시험을 수행하였다. 시험을 통해, 본 연구에서 제안한 실시간 착석 확인 및 도착알림기능이 포함된 압전소자기반 스마트 좌석 시스템의 실현 가능성을 검증하였다. 본 연구 결과는 향후 실용화를 통해 검토 업무 효율화를 통한 고소철도 서비스의 질적 향상에 기여할 수 있을 것이다.

• Structural Engineering and Mechanics
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• 제30권2호
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• pp.177-190
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• 2008

Material failure behavior is generally dependent on loading rate. Especially in brittle and quasi-brittle materials, rate dependent material behavior can be significant. Empirical formulations are often used to predict the rate dependency, but such methods depend on extensive experimental works and are limited by practical constraints of physical testing. Numerical simulation can be an effective means for extracting knowledge about rate dependent behavior and for complementing the results obtained by testing. In this paper, the failure behavior of a brittle material under different loading rates is simulated by molecular dynamics analysis. A notched specimen is modeled by sub-million particles with a normalization scheme. Lennard-Jones potential is used to describe the interparticle force. Numerical simulations are performed with six different loading rates in a direct tensile test, where the loading velocity is normalized to the ratio of the pseudo-sonic speed. As a consequence, dynamic features are achieved from the numerical experiments. Remarkable failure characteristics, such as crack surface interaction/crack arrest, branching, and void nucleation, vary in case of the six loading cases. These characteristics are interpreted by the energy concept approach. This study provides insight into the change in dynamic failure mechanism under different loading rates.

• 유통과학연구
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• 제17권10호
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• pp.17-26
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• 2019

Purpose - This research investigates the old marketing mix approach to satisfaction and loyalty from the perspective of research subjects of Samsung brand smartphone cases through empirical testing involving product quality, price, distribution channel variables as antecedent variables. Research design, data, and methodology - This study emphasizes the empirical/quantitative concept by using a survey as a data collection tool. The number of samples used was 179 eligible respondents who used Samsung smartphone devices for more than five years. Statistical testing tools use PLS with several testing stages such as the classical assumption test to the hypothesis testing stage. Results - The nine hypotheses proposed, as many as two hypotheses were proposed, namely intervening relationships involving Price and Distribution channel variables on customer satisfaction and customer loyalty. Conclusions - Product quality is the essential component affecting customer satisfaction and loyalty while distribution channel is a complementary component that is no less important to measure the extent to which customer satisfaction expectations and customer loyalty are realized for the product quality of the products that have been produced and marketed. The price component is not the only reason to make consumers satisfied and loyal.