• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.39.3-40
• /
• 2015

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument optimized to the first small satellite of NEXTSat series. The capability of both imaging and low spectral resolution spectroscopy in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the main targets are nearby galaxies, galaxy clusters, star-forming regions and low background regions. The off-axis optical design of the NISS with two linear variable filters is optimized to have a wide field of view ($2deg.{\times}2deg.$) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. The mechanical structure is considered to endure the launching condition as well as the space environment. The dewar inside the telescope is designed to operate the infrared detector at 80K stage. From the thermal analysis, we confirmed that the telescope and the dewar can be cooled down to around 200K and 80K, respectively in order to reduce the large amount of thermal noise. The stray light analysis is shown that a light outside a field of view can be reduced below 1%. After the fabrications of the parts of engineering qualification model (EQM), the NSS EQM was successfully assembled and integrated into the satellite. To verify operations of the satellite in space, the space environment tests such as the vibration, shock and thermal-vacuum test were performed. Here, we report the results of the critical design review for the NISS.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.25 no.1
• /
• pp.239-264
• /
• 2014

The study aims to study the user perception and satisfaction on the current church library services in Korea. 100 registered attendees and 10 priests, from three different groups were randomly selected for the survey. Three groups - the one with its own library, another with a community type library, and the other without church library - were compared. A literature review and survey were executed, and the questionnaires of the survey for analysis in this research contained demographic information, usage of church library, mission and function of the church library, library space, librarians, collection, community services of the church library, and perception on the effect of the library's community service on a specific religious activity (evangelism). The analysis revealed that the satisfaction level on church library service was relatively high (3.5 point on average, 5-point Likert scale), even though the frequency of using the church library service was relatively low. The study also found that users perceived the library as a community library or archives of the church, and study rooms and reading rooms as its major functions. It reveals that religious materials were preferred as the church library collection and the service of the church library to its community was perceived as being a effective and positive factor on evangelism. Applying church library service should be considered in order to enhance the understanding on the religion and effective results of evangelism.

• Korean Journal of Remote Sensing
• /
• v.32 no.3
• /
• pp.287-305
• /
• 2016

Over the past half century, satellites have continuously expanded their roles in remote sensing applications. As the number of satellites to be launched are expected to continuously increase in coming years, the research on satellite payloads will be in high demands. Earth Observation (EO) satellites are nowadays widely utilized for various purposes. Especially, Agriculture and forestry applications are considered as their major application areas. Since about 85% of domestic land cover is classified as forest or cropland areas, it would be reasonable to suggest that the demand for these satellites should be of high priority. In this paper, a comprehensive analysis is performed on the technical specifications of satellite payloads that may be applicable to agricultural applications. We attempted to build a solid database on payload specifications by collecting relevant information available from various related institutes and academic research works. A number of experts involved in national agricultural research and satellite development programs have been invited to investigate required payload design. Based on the current technology development status and future plan, multiple options for future satellite payload designs have been suggested bearing in mind that the results may be applicable to the future agriculture and forestry satellite payload design. The proposed payload specifications are analyzed in depth through satellite operation simulations under the mission of observing the national agriculture areas. The proposed design scheme and simulation results may be used as technical references to satellite payload design for future space missions.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.5
• /
• pp.372-379
• /
• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.46 no.1
• /
• pp.87-96
• /
• 2009

In conventional method, flight model is discribed to differential equation by linealization of nonlinear object motion equation. As state equation from differential equation of moving object, the controller is designed by transfer functions of each module under discrimination of stability criteria. But this conventional method is designed under limitation of nonlinearity from object's shape and speed. In other word, The greater part of guidance/navigation system was satisfied with the result of good performance for normal figure of flight object, not sudden changed flight condition, not high speed. But it is not able to give full play to its ability on flight object which has abnormal figure, sudden changeable motion, high speed. Therefore, in this paper was presented performance analysis of load control model for navigation/guidance system on flying object being uncertainty, non-linear like abnormal figure, sudden changeable motion, high speed and is presented method of trajectory control(controllability) ahead of controllability and stability to achieve flight mission. In other word, this paper shows the first step of Min-design method and flight control model.

• Aerospace Engineering and Technology
• /
• v.2 no.1
• /
• pp.171-181
• /
• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.

• Journal of the Society of Disaster Information
• /
• v.8 no.3
• /
• pp.287-296
• /
• 2012

This study is analysis of the existing domestic terrorism factors and suggest countermeasures for political leadership that can occur to the precautionary terror occasion of the presidential election approached 100 days in the future. Political terror caused mainly achieved peak of Ideology or social conflict by Politically alienated class. Common cause is most likely to occur when the party or the government want to attack a target or can not stand disadvantaged and lose that I suppert the party or the government. 21st century political terror is occurred with Misfits of complaints expressed or social conflict more frequency than attack used random people, new weqpon and bomb. It is interpreted that issued as a drastic measure from individual complaint because of increased polarization of wealth by separate into group and fallen law and order but also we are not familiar with the political compromises. Personal safety escort mission is essential condition of political activity that Absolute personal protection and to come up with a large number of voters for best result. Thus security guard ought to professional security activity depend on gathered situation, location and regional feature for perfect protection service.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.21 no.7
• /
• pp.1236-1246
• /
• 1997

본 연구는 1960년대 미국의 청년층에 의해 일어난 반문화적인 현상으로 인식되어온 동양문화의 도입, 특히, 인도문화가 청년문화 전반에 끼친 영향과 더 나아가 이러한 환경변화가 미국대학복식에 미친 영향을 알아보고자 하였다. 1960년대 미국청년문화에 나타난 인도 문화의 영향은 철학, 종교 대중음악 등 다방면에서 보여졌으며, 또한 복식의 형태에도 반영되었다. 복식학자들에 의한 단편적인 추론에만 그쳤던 이러한 복식의 현상을 본 연구는 문헌조사에 의한 객관적이고 과학적인 연구방법을 이용하여 입증하고자 시도하였다. Washington, D.C.와 San Francisco/Berkeley 지역에 위치한 7개의 대학교에서 1960년 부터 1975년 사이에 발행한 대학신문에서 연구자료를 수집하여, 체계적인 자료수집 및 분석을 위한 연구방법으로 사회과학분야에서 주로 사용되어 온 Content Analysis Method를 이용하였다. Content Analysis Method는 예비연구(preliminary study)의 결과를 기초로 인도 복식의 영향을 받은 미국대학복식의 형태를 크게 의복(clothes), 장신구(accessories), 직물(fabrics) 등의 3개 category로 분류하여, 다시 13개의 subcategory(kurta, midriff top, Nehru jacket/suit, Indian shirt/blouse/smock/dress, sari, Indian jewelry, Indian sandal, Indian urn, Indian bedspread. Indian embroidery, Indian print, madras, tie-dye)로 세분하였다. 복식의 형태에 의한 분류외에도, 대학신문의 광고나 기사에 실린 내용을 인도복식이 미친 엮향의 정보를 알아보기 위하여 Attribution information을 3 category(originated, attributed, connotated)로 분류하여 조사하였다. 더불어, 같은 문헌에 나타난 인도에서 도입된 4개의 주된 종교(Transcendental Meditation, Hare Krishna, Yoga. Divine Light Mission)의 빈도도 조사하였다. 본 연구의 결과는 13개의 가인도복식스타일(Indian style)의 Frequency(빈도), Attribution, Duration(기간)의 내응을 포함하는 표로 요약되었다. 또한, 연도별로 Indian style이 나타난 빈도의 Duration(기간)의 내용을 포함하는 표로 요약되었다. 또한, 연도별로 Indian style이 나타난 빈도의 합계와 연도를 축으로 하는 막대그래프를 작성하고 이 그래프에 Attribution Category의 내용도 함께 볼 수 있도록 정리하였다. 대학복식에 나타난 인도의 영향은 여성복식과 남성복식에 있어서 서로 유사점과 차이점이 보이는데, 인도의 영향이 여성복식에 있어서 그 빈도가 더 높고, 종류가 더 다양함을 볼 수 있다. 여성복식에 있어서는 12가지의 다양한 인도복식스타일이 나타났으며, 그중 가장 많이 보이는 스타일은 Indian Shirt/Blouse/Smock/ Dress이며, 그 뒤를 이어 Madras, Indian lowery등을 볼 수 있다. 남성복식애 나타난 7가지의 스타일 중에는 Madras가 가장 빈도가 높으며 그외의 스타일들은 그 빈도가 매우 낮음을 볼 수 있다. 인도의 영향의 정도 (Attribution Categories) 있어서는 여성과 남성복식 모두에 있어서 인도에서 직접 수입된(originated) item이 각각 전체의 90%와 81%를 차지하여, 인도복식의 영향은 받았으나 미국내에서 제작된(attributed and connotated) item 보다 휠씬 더 많은 수를 보였다. 인도복식스타일이 가장 많이 보여지는 시기(Peak period)는 여성과 남성복식에 있어 모두 1968년에서 1971년 사이로 공통점을 보였다. 이러한 결과는 미국 청년 문화에 전반적으로 나타났던 반문화적 현상과 동일한 시기로서, 이는 사회 현상이 복식에도 반영되고 있음을 알 수 있다. 또한 같은 시기의 대학신문에 나타난 인도에서 도입된 4 개의 종교 역시 1960년대 후반 부터 그 빈도가 증가하여 1970년에 리고의 빈도가나타낭으로서 앞의 결과를 뒷받침해 주고 있다. 본 연구에서는 Washington,D.C.와 San Francisco/Berkeley 지역의 대학신문만을 연구자료로 사용하였으나 앞으로는 새로운 연구 자료의 발굴과 연구대상을 타 지역으로 확대시키므로서 미국내 전체의 청년복식에 대한 이해를 증가시킬 수 있을 것이다.

• The Journal of the Korea Contents Association
• /
• v.14 no.9
• /
• pp.285-297
• /
• 2014

This research is involved in looking into the cognition pattern of social worker position of a fourth-year student majoring in Social Welfare. The purpose of this research is to offer a basic data needed for education of the students who are preparing to get a job of a social worker. For this, applying Q methodology, this research made an objective analysis of their subjective response to social worker position targeting the 30 students in the department of social welfare at the four-year-course college located in Gyeongsangbuk-do and Gyeongsangnam-do. The research results showed that the cognition pattern of the college students' occupational view on social welfare position could be categorized into the three; The first pattern is a "job-skeptic & reality-evasive" type, who tends to perceive the position of a social worker as the one having a lot of job exhaustion and much workload, showing a pessimistic view on the meaning or a sense of mission of a social worker position. The second pattern is a "practice-centered & specialized-job-seeking type" who tends to think much of practical aspects of a social worker job and to seek after the position of a social worker as a specialized job, and at the same time to rely on the policy or system for a social worker position. The third pattern is a "value-oriented & self-achievement type", who tends to think much of the necessity of value or ethics in putting social welfare into practice and also to make much of self-achievement through the channel of a social welfare worker position. Taken together, it might be possibile to turn out professional human resources, but this research thinks it is more necessary to place the education of values of a social welfare worker.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.27 no.6
• /
• pp.635-642
• /
• 2014

In this paper, an efficient technique is developed to predict failure probability of three failure modes(case rupture, fracture and bolt breakage) related to solid rocket motor case due to the inner pressure during the mission flight. The overall procedure consists of the steps: 1) design parameters affecting the case failure are identified and their uncertainties are modelled by probability distribution, 2) combustion analysis in the interior of the case is carried out to obtain maximum expected operating pressure(MEOP), 3) stress and other structural performances are evaluated by finite element analysis(FEA), and 4) failure probabilities are calculated for the above mentioned failure modes. Axi-symmetric assumption for FEA is employed for simplification while contact between bolted joint is accounted for. Efficient procedure is developed to evaluate failure probability which consists of finding first an Most Probable Failure Point(MPP) using First-Order Reliability Method(FORM), next making a response surface model around the MPP using Latin Hypercube Sampling(LHS), and finally calculating failure probability by employing Importance Sampling.