• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.26-26
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• 1998

우주항공 산업에 대한 관심 증가에 따라 지상에서 많은 연소시험을 시행하고 있으나, 소음 발생문제에 부딪혀 어려움을 겪고 있는 실정이다. 따라서 초보적 단계이기는 하나, 액체로켓 엔진의 추력 손실을 최소화시키고 최대한 제트 소음을 크게 줄일 수 있는 소음기를 연구, 개발하고 있다. 본 연구에서는 제트소음에 대한 기초연구를 수행하여 물분사형 소음기를 설계 및 제작하였고, 물분사량과 소음기의 기하학적형상이 소음 특성에 미치는 영향을 연구하였다. 본 실험범위에서 연구의 결과는 다음과 같다. 1. 동일한 물 분사량 조건에서, 소음기 길이가 노즐출구 직경의 10배 모델 보다 30배 모델이 9dbl 정도 감음효과를 보였다. 2. 불 분사량이 증가함에 따라 소음레벨은 감소하였고, 30배 모델의 경우 불분사량이 배기가스의 10-12배 조건에서는 소음레벨을 91dbl까지 줄일 수 있었다. 3. 상기조건(소음레벨 91dbl)에 확장관을 부착함으로써, 소음레벨을 약 86dbl까지 줄일 수 있었다. 4. 본 형태의 물분사방식을 채택할 경우 고온배기가스로 인한 소음기의 파손을 방지하기 위해서 반드시 막냉각장치의 설치가 요구된다.

• Journal of the Korean Society of Costume
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• v.58 no.10
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• pp.95-111
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• 2008

Now when Wests meet Easts, they approach with a motive of acknowledging Eastern or Asian value, concretizing and sharing philosophy. As the result of this study through comparing Eastern and Western view of thinking, First, East is the cosmic beauty of harmony that pursues the harmony with the nature involving emotional and humane affection, and West has the tendency of proportional beauty of harmony involving order and balance. Second, East pursues the metaphorical beauty of mimesis which implies more in invisible parts, and West has the tendency of pursuing visual beauty of mimesis which has contents in visible parts. Third, East is the sublime beauty of nothingness which suggests a blank is endless infinitude of doctrines and mind breath, and West pursues the sublime beauty of being which desires to fill tangible existence without blank. Fourth, East is the expressive beauty that has the intuition of pleasure, which gives weight on non-clearness, emotional joke, and satire, and emphasizes a comic phase, and in West pursuing clearness of order, the concept of the ugliness of disformation is the intuition of defiance, and close to intuition of sadness.

• Composites Research
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• v.21 no.5
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• pp.9-14
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• 2008

Carbon nanofibers (CNFs) were used as dielectric lossy materials and NiFe particles were used as magnetic lossy materials. Total twelve specimens for the three types such as dielectric, magnetic and mixed radar absorbing materials (RAMs) were fabricated. Their complex permittivities and permeabilities in the range of $2{\sim}18$ GHz were measured using the transmission line technique. The parametric studios for reflection loss characteristics of each specimen to design the single-layered RAMs were performed. The mixed RAMs generally showed the improved absorbing characteristics with thinner matching thickness. One of the mixed RAMs, MD3with the thickness of 2.00 mm had the 10 dB absorbing bandwidth of 4.0 GHz in the X-band ($8.2{\sim}12.4$ GHz). It also showed very broad 10 dB absorbing bandwidth as wide as 6.0 GHz in the Ku-band ($12.0{\sim}18.0$ GHz) with the thickness tuning to 1.49 mm. The experimental results for selected several specimens were in very good agreements with simulation ones in terms of the overall reflection loss characteristics and 10 dB absorbing bandwidth.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.141-155
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• 1997

The universe has its order of yang and yin : all creation are continuously generated, grow and die, which is the results of the harmonious operation by yang and yin. Among all creation, the human is one of the samjae(three bases of the world, which are heaved earth, and man) and he is from the combined sukhi(a superior khi) of yang and yin. And human life itself is basically a condensed jonghyul (life blood) and at the same time it is only a transient joining of sadae(the four elements of earth, air, fire and water). Yang and yin, the two axes of the world, therefore. are the most crucial and fundamental concept to explain the generation and extinction of alt creation, to understand people in time and space. to find out the reality of human life as an organism, and, at last, to observe the state of human health. If so, what is the most essential idea in yang and yin\ulcorner It is taegeuk(chungkhi) or tao(of one yang and one yin). If the property of heaven and earth is kongon, taegeuk is a khi and tao a principle. And it can be said that a human body is merely a union of hyung and khi, that human life is an essence of sambo, jeongkhishin, that human health is a harmoninzed coordination of yang and yin because it is from the combined sukhi of yang and yin. Hyung. a vessel for sambo, jeongkhishin, is at the bottom and shin is on the top : the personality and the disposition of individuals differ according to their working. Thus. on the basis of the above discussion. the following can be offered as some suggestions for Korean Nursing Theory. Though human beings are part of Nature, they are the most eminent microcosm among all creation. So, as a subjet for nursing, a person should be understood with khijok kyoryu rather than with logical thinking, then mutual trust between the patient and the nurse can be established. The health of a person depends on the harmony of yang and yin. To be healthy, a person should consider harmonization with Nature(including his surroundings) as well as a balanced human relationships in society. Moreover, it is crucial for each person to obtain hoshim as a method of mind control rather than to only treat the symptoms of disease.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.75-94
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• 2021

The low birth rate and shortened military service period are causing concerns about selecting excellent military officers. The Republic of Korea entered a low birth rate society in 1984 and an aged society in 2018 respectively, and is expected to be in a super-aged society in 2025. In addition, the troop-oriented military is changed as a state-of-the-art weapons-oriented military, and the reduction of the military service period was implemented in 2018 to ease the burden of military service for young people and play a role in the society early. Some observe that the application rate for military officers is falling due to a decrease of manpower resources and a preference for shortened mandatory military service over military officers. This requires further consideration of the policy of securing excellent military officers. Most of the related studies have used social scientists' methodologies, but this study applies the methodology of text mining suitable for large-scale documents analysis. This study extracts words of discriminative characteristics from the Republic of Korea Air Force Non-Commissioned Officer Applicant cover letters and analyzes the polarity of pass and fail. It consists of three steps in total. First, the application is divided into general and technical fields, and the words characterized in the cover letter are ordered according to the difference in the frequency ratio of each field. The greater the difference in the proportion of each application field, the field character is defined as 'more discriminative'. Based on this, we extract the top 50 words representing discriminative characteristics in general fields and the top 50 words representing discriminative characteristics in technology fields. Second, the number of appropriate topics in the overall cover letter is calculated through the LDA. It uses perplexity score and coherence score. Based on the appropriate number of topics, we then use LDA to generate topic and probability, and estimate which topic words of discriminative characteristic belong to. Subsequently, the keyword indicators of questions used to set the labeling candidate index, and the most appropriate index indicator is set as the label for the topic when considering the topic-specific word distribution. Third, using L-LDA, which sets the cover letter and label as pass and fail, we generate topics and probabilities for each field of pass and fail labels. Furthermore, we extract only words of discriminative characteristics that give labeled topics among generated topics and probabilities by pass and fail labels. Next, we extract the difference between the probability on the pass label and the probability on the fail label by word of the labeled discriminative characteristic. A positive figure can be seen as having the polarity of pass, and a negative figure can be seen as having the polarity of fail. This study is the first research to reflect the characteristics of cover letters of Republic of Korea Air Force non-commissioned officer applicants, not in the private sector. Moreover, these methodologies can apply text mining techniques for multiple documents, rather survey or interview methods, to reduce analysis time and increase reliability for the entire population. For this reason, the methodology proposed in the study is also applicable to other forms of multiple documents in the field of military personnel. This study shows that L-LDA is more suitable than LDA to extract discriminative characteristics of Republic of Korea Air Force Noncommissioned cover letters. Furthermore, this study proposes a methodology that uses a combination of LDA and L-LDA. Therefore, through the analysis of the results of the acquisition of non-commissioned Republic of Korea Air Force officers, we would like to provide information available for acquisition and promotional policies and propose a methodology available for research in the field of military manpower acquisition.

• Composites Research
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• v.21 no.2
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• pp.31-35
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• 2008

In order to design light weight and high efficient electromagnetic wave absorbing materials, hollow magnetic particles have been introduced in this study. The electroless plating method has been utilized to coat Ni and Fe on the substrates of synthesized polystyrene particles of submicron size. Removing polystyrene particles by heat treatment resulted in hollow structures. Observation by SEM, TEM and EDS confirmed the surface morphology and coating thickness of Ni and Fe. Polymeric composites containing hollow particles were tested in order to compare the electromagnetic properties between Ni coated and Fe costed particles. The composite of 30 wt% Fe hollow particles showed the higher complex permeability than Ni hollow particles or the conventional barium ferrite particles.

• The Korean Journal of Air & Space Law and Policy
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• v.18
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• pp.385-444
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• 2003

Current Military Airbase Law, in an effort to promote safety of military aircraft and security of military airbase, requires an administrative agency or its empowered branch to consult with the Secretary of Defense or the commander of the airbase before they issue a certain administrative approval or decision related to the installation. Although this consultation process purports itself in simplifying what can be an protracted administrative procedure, and in unifying objectives of the military and the administrative services, such procedural requirement is vulnerable inevitability of various legal problems whenever there is a conflict of interests among civil, military, government services. Nor is there sufficient studies done by academian in the area of bureaucratic issues of administrative resolution, and certainly not in the area of the military consultation procedure. This article, with such reality in mind attempts to constructively examine 1) when a consultation application is submitted, whether the discretionary power of the commander of the affected airbase is acknowledged at the outset; 2) if the content of the consultation is deemed unlawful, whether a civilian can institute an administrative lawsuit against it; 3) problems about the subject matters of the consultation requirement within the framework of military airbase law; 4) whether the issuing administrative agency must abide by and issue approval or decision in accordance with the opinion proposed by the said commander; 5) the legal problems of the remedial measure such as an order of removal, appellate review, notion to challenge authority, and etc. in cases such as administrative agency ignoring the commanders proposal or issuing final approval or decision that is inconsistent with what was consulted and agreed upon between both parties.

• The Korean Journal of Air & Space Law and Policy
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• v.19 no.1
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• pp.141-163
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• 2004

The limits in the use of force against a civil aircraft which intrudes into sovereign airspace have not been defined in the aspect of international law. Therefore, this paper intends to analyze international laws and practices about sovereign airspace intrusions by the civil aircraft, and to examine the legality in the use of force against the civil aircraft hijacked by means of political terrorism, in particular. In this paper, the sphere of study is restricted within the problems of interception against the civil aircraft which intrudes into sovereign airspace in times of peace, excluding the problems against a state aircraft, and the responsibilities for the civil or criminal affairs due to interceptions. Herein this paper analyzes the existing international laws and the cases of each nation's use of force against the civil aircraft which intrudes into sovereign airspace, and organizes the conditions in the use of force which have been accepted in international laws and practices, and then applies them to the special case of civil aircraft hijacked by political terrorism. Consequently, this paper suggests that the basic principles of necessity, ultimateness, and proportionality be taken into consideration in the use of force against civil aircraft which intrudes into sovereign airspace. This study finally suggests that the possibility in the use of force against civil aircraft hijacked by political terrorism might be higher than any type of civil aircraft intrusions into sovereign airspace due to the factor of necessity of national security concerned.

• Korean Journal of Culture and Arts Education Studies
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• v.9 no.3
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• pp.45-61
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• 2014

Recently, there is a discussion about culture theory in the area of traffic safety regulation. It has the view that the subject of criticism, etc. by drivers' regulation interpretation, awareness about the danger of regulation violation and nonacceptance of regulation can be changed according to the way drivers' cultural bias was formed. According to the culture theory, fundamental views of the world in particular social relations surrounding individuals, world view or cosmology, are formed and the world view makes an effect on individual behavior and attitude. In this context, cultural cognition and cultural learning theory which are suggested in Christoph Wulf's study on historical-cultural anthropology provide new approach toward this phenomenon. According to his insistence, core mechanisms which can explain cultural cognition and cultural learning are systematized by five things; physical characteristic, mimesis, performance theory, rite and image. The purpose of this research is to investigate the changes by the way Korean people cognize traffic regulations culturally and experiences of traffic regulation violation through the analytic frame of Christoph Wulf's five core mechanisms. To achieve it, cognition of traffic culture was analyzed by analytical phenomenology for drivers who had been educated due to their violation of traffic regulations. Value, lifestyle and practicing methods which are pursued by people work in sociocultural context rather than are influenced by cognitive structure of individuals.

• Journal of Astronomy and Space Sciences
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• v.25 no.3
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• pp.267-282
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• 2008

The GNSS (Global Navigation Satellite System) signal is delayed by the neutral atmosphere at the troposphere, so that the delay is one of major error sources for GNSS precise positioning. The tropospheric delay is an integrated refractive index along the path of GNSS signal. The refractive index is empirically related to standard meteorological variables, such as pressure, temperature and water vapor partial pressure, therefore the tropospheric delay could be calculated from them. In this paper, it is presented how to generate meteorological data where observation cannot be performed. KASI(Korea Astronomy & Space Science Institute) has operated 9 GPS (Global Positioning System) permanent stations equipped with co-located MET3A, which is a meteorological sensor. Meteorological data are generated from observations of MET3A by Ordinary Kriging. To compensate a blank of observation data, simple models which consider periodic characteristics for meteorological data, are employed.