• Journal of the Mineralogical Society of Korea
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• v.8 no.2
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• pp.57-72
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• 1995

춘천 지역 선캠브리아기의 구봉산층군 내의 백운석질 대리암에는 광역변성작용의 산물로서 조립질의 투각섬석이 주된 규산염 광물상을 이루며 산출된다. 이들은 배태 층준과 원암의 조성에 따라 두 가지 유형으로 구분된다. : (1) 투각섬석(흑회색)+방해석+백운석+활석, (2)투각섬석(백색)+금운모+백운석+방해석+K-장석, 백색의 투각섬석이 흑회색형보다 상대적으로 높은 Al과 알칼리 함유도를 보이지만, 전반적으로 모두 Mg-단종에 가까운 화학 조성을 갖는다. 투각섬석들이 격자 구조상의 결함 구조를 갖지 않는데 비해서, 금운모는 1M 구조형을 이루고 저면 격자 간격상에 녹니석 단위의 빈번한 개재에 의한 격자상의 구조적 결함이 흔히 관찰된다.방해석-백운석 지온계에 대한 연구와 TWEEQU 프로그램을 이용한 상평형도 작성을 통해서, 투각섬석들은 500~$600^{\circ}C$의 온도 범위, 8kb 정도의 압력 및 Xco2=0.2~0.5 조건에서 생성된 것으로 해석하였다. 이 지역의 투각섬석은 위와 같은 조건에서 지속적으로 평형 상태가 유지되고 상안정도가 증대되므로서, (1) 투휘석을 수반하지 않고, (2) 격자 구조상의 결합을 갖지 않는, (3) 자형의 큰 결정을 이루게 된 것으로 해석된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.8
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• pp.657-663
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• 2014

Since 2007, the defect confirmation test for vehicles using PEMS has been enforced in USA. This test can measure emissions from on-street vehicles using a device mounted on a car. Europe has confirmed its plan for introducing this test from EURO6, 2013. Thus, the Korean government is also under pressure to adopt this method that reflects the real-world driving conditions using PEMS, considering the emission controls for domestic heavy-duty vehicles. To provide various utilizations of the PEM, this emission test has been developed in accordance with the type of driving road, DPF, ISG, and air conditioner. This research aims to provide the fundamental materials for implementing defect confirmation tests for commercial vehicles, which are appropriate for domestic emission control situations, after studying the defect confirmation test methods for heavy-duty vehicles using PEMS.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.370-378
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• 2015

The data acquisition unit, signal acquiring and processing equipment, processes and provides major data of an aircraft such as engine system, power train system, hydraulic system, etc. However, it had lots of failure related to the system during production test flight, and it is necessary to fix them perfectly as soon as possible because of the significance of the equipment. In this paper, it contains failure classification and analysis for each defect element to improve whole software as well as electrical circuit. Particularly, utilizing Fault Injection Method based interworking test, more efficient improvement activity was performed for not only equipment level but also aircraft level, and as a result, it is achieved that considerable betterment of Surion quality and flight safety.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.447-454
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• 2010

The defects of rail head induced by fatigue and deterioration are mainly classified by two types ; one occurred on the surface of rail head the another occurred on the inner rail head. This study performed the surface irregularity measurement of rail head according to the passing tonnage in the urban railway. Also, we carried out microscopic structure test, chemical component test and micro-hardness test for the specimen which is the used rail on metro line by accumulated passing tonnage. As a result of this study, for new rail, it should be performed initial grinding in order to remove 0.3mm of de-carbonized layer. The preventive-cyclic grinding for preventing RCF defects is proposed two options : grinding by the whole line and grinding by specified sections.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.234-234
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• 2021

국내 기반시설의 대부분은 1970년대 경제성장기에 건설되어 사용연수가 30년 이상 경과하였고 급격한 고령화가 진행 중이다. 1990년대 성수대교와 삼풍백화점의 붕괴는 시설물 유지관리의 중요성에 대한 전국민적 관심을 집중시켰고, 이에 정부는 1995년 「시설물의 안전관리에 관한 특별법」 제정을 시작으로 현재까지 다양한 정책 및 기준을 수립해왔다. 일반적으로 안전점검 및 정밀안전진단 등을 수행하여 시설물의 안전등급을 평가하고 결함에 대한 보수·보강을 실시하여 시설물을 유지·관리하고 있다. 그러나 유지관리 예산은 한정적이기 때문에 모든 결함에 대한 보수·보강 사업을 실시할 수 없는 실정이다. 이에 보수·보강 조치의 우선순위를 선정하는 것이 필요하며, 관련 법령 세부지침에는 부재의 중요도, 결함의 심각성, 경제성을 고려한 우선순위지수(PI, Priority Index)를 제시하고 있다. 이 식은 전문가의 주관적인 판단에 의해 영향도를 50~100%범위 안에서 조정할 수 있으며, 일부 특정 부재는 동일한 가중치가 설정되어 있다. 또한 결정적으로 보수보강을 통한 효과를 효율적으로 고려하지 못하고, 대부분 경제성에 의해 우선순위가 결정되는 한계점이 발생한다. 따라서, 본 연구에서는 몇 가지 사례분석을 통해 현재 우선순위지수에 대한 문제점을 고찰하고 이를 개선할 수 있는 우선순위 산정식(PI)을 제시하였다. 과거 유지관리 시행 초기에는 보수보강 사례가 부족하였지만 현재는 수십년간의 축적된 자료를 바탕으로 제시된 산정식을 충분히 활용할 수 있을 것으로 판단된다. 향후 보수보강 효과를 정량화하는 방법에 대한 추가적인 연구가 수행된다면 더욱 경제적인 측면에서 우선순위를 산정할 수 있을 것이며 노후화된 기반시설 유지관리방안에 효과적으로 사용될 것으로 기대된다.

• Journal of the Korean Vacuum Society
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• v.11 no.1
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• pp.50-58
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• 2002

The growth of GaN films on Si substrate has many advantages in that Si is less expensive than sapphire substrate and that integration of GaN-based devices with Si substrate is easier The difference of lattice constant and thermal expansion coefficient between GaN and Si is larger than those between GaN and sapphire. However, which results in many defects into the grown GaN. In order to obtain high duality GaN films on Si substrate, we need to reduce defects using the buffer layer such as AlN. In this study, we prepared three types of AlN buffer layer with various crystallinity on Si (111) substrate using MOCVD, Sputtering and MOMBE methods. GaN was grown by MOCVD on three types of AlN/Si substrate. Using TEM and XRD, we carried out comparative investigation of growth and properties of GaN deposited on the various AlN buffers by characterizing lattice coherency, crystallinity, growth orientation and defects formed (voids, stacking faults, dislocations, etc). It is found that the crystallinity of AlN buffer layer has strong effects on growth of GaN. The AlN buffer layers grown by MOCVD and MOMBE showed the reduction of out-of-plane misorientation of GaN at the initial growth stage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.680-687
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• 2016

Although advanced weapon system weapons with high-performance and various functions have been developed, weapon defects can be fatal in the weapons industry. Therefore, the army requires quality improvement to reduce the number of defects which occur during both the development and operation of the weapon system. Recently, many manufacturers, including weapons manufacturers, have conducted analyses using defect related big-data in order to improve the quality. However, there have been few data analyses, because it is difficult to obtain the data required for the analysis of the development phase. Therefore, this study summarizes the pattern of the weapon system, military organization, and defect types using the actual data of the Post-Logistics Support (PLS) phase. The PLS data, which is referred to as the data collected after force integration, includes information on requests for maintenance. Through this information, this study selects key variables and analyzes the selected variables. The analysis results show the critical factors to be considered during the development phase. Finally, this study proposes a framework for advanced PLS systems using the PLS data. The proposed framework enables the development time of weapon systems to be further shortened and their quality to be improved.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.309-319
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• 2018

Previously, six Schizosaccharomyce pombe mutants that induce pheromone even in the presence of nitrogen source were isolated from a bank of temperature sensitive mutants. In this report, one of these mutants, pws6 was further characterized. The pheromone induction in pws6 mutant cells was specific to nutrient: the M-factor pheromone was induced without nitrogen starvation but not without glucose starvation. This result suggests that the pws6 mutant might have a specific defect in the pathway for nitrogen starvation. The pws6 mutant induces P-factor pheromone as well as M-factor without starvation of nitrogen in temperature sensitive mode, suggesting that the pheromone induction phenotype of pws6 mutation is not cell-type specific. From cloning of the $pws6^+$ gene by complementation of the temperature sensitive growth defect, three plasmids containing 8.1 kb, 3.3 kb, and 4.8 kb yeast DNA were recovered. These plasmids complement the growth defect of the pws6 mutant by 100%, 70%, and 10~20%, respectively. The abilities of these plasmids to complement pheromone induction phenotype of pws6 mutant cells were correlated well with the efficiencies of complementation of the growth defect. With comparison of their open reading frames to the complementation efficiencies, it is concluded that the open reading frame, SPBC19C7.06 is responsible for the complementation of temperature sensitive phenotype of the pws6 mutant. This open reading frame, named prs1, contains one long exon with no intron and encodes a putative prolyl tRNA synthetase. The putative Prs1 protein exhibits significant similarities to the prolyl tRNA synthetases of other species.

• Archives of design research
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• v.14 no.4
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• pp.137-146
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• 2001

The purpose of the study is to explore and understand the product development through the theory of evolution. For the purpose of the study, an evolution mechanism was set up in which the products were applied with. The results showed three distinguishable types of product evolution 'the evolution of functions','the evolution of forms'and 'the evolution of symbols what the products represent'. In order to answer the research questions, , , , the research was carried out in three ways: firstly, some ideas of product evolution were looked closely through existing researches; secondly, the study explored the idea of evolution mechanism being a natural process like an organic system; finally by applying various products with the evolution mechanism, different patterns of product evolution were classified. The results of the study can be summarised as follows: ${\bullet}$ The evolution mechanism in this study can be defined as an 'organic system'that consists of the causes of evolution'(based on the needs and the willingness to have pleasure), 'the point of evolving'(based on a degree of imperfection) and 'the motive of evolution'(based on the readiness to make profit). ${\bullet}$ The evolution mechanism seems to suggest three different patterns in product evolution,'the evolution of functions', 'the evolution of forms' and 'the evolution of symbols'

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.35-46
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• 2017

Spare engine plays an important role for securing readiness of military strength during unexpected fault occurrences and field/depot planned maintenances. The purpose of this research is to present an approach towards the optimal number of spare engines/modules for diversity of aircraft types. We first reviewed two representative approaches, METRIC and meta model. We then investigated military aircrafts and categorized them into 5 types with regard to the engine type and number of engines/modules per aircraft. Through rigorous investigation of planned/non-planned maintenance of each type, we drew parameters and variables involved. As known, due to the complexity of the problem, it is impossible to develop a simple mathematical model with a closed form solution. Based on the airbase operation and maintenance logic with parameters/variable drawn, we developed a simulation model using ARENA well representing real field exercises. For the optimal solution, we applied OptQuest. It has shown that the program developed generates reliable results through a set of case examples.