• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.2
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• pp.87-92
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• 2015

Mucopolysaccharidosis (MPS) is an inherited disease entity associated with lysosomal enzyme deficiencies. MPS type 2, also known as Hunter syndrome, has a characteristic morphology primarily involving x-l inked recessive defects and iduronate-2-sulfatase gene mutation. The purpose of this case report is to provide important clues to help pediatricians identify Hunter syndrome patients earlier (i.e., before the disease progresses). A 30-month-old boy showed developmental delay and decreased speech ability. Physical examinations revealed a flat nose and extensive Mongolian spots. Brain magnetic resonance images (MRIs) showed bilateral multiple patchy T2 hyperintense lesions in the periventricular and deep white matter, several cyst-like lesions in the body of the corpus callosum, and diffuse brain atrophy, which were in keeping with the diagnosis. Based on these findings, the patient was suspected of having MPS. In the laboratory findings, although the genetic analysis of IDS (Iduronate-2-sulfatase) did not show any pathogenic variant, the enzymatic activity of IDS was not detected. We could confirm the diagnosis of MPS, because other sulfatases, such as ${\alpha}$-L-iduronidase, were detected in the normal range. Early enzymatic replacement therapy is essential and has a relatively good prognosis. Therefore, early diagnosis should be made before organ damage becomes irreversible, and brain MRIs can provide additional diagnostic clues to help distinguish the disorder.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.531-537
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• 2016

The damage and fracture of machine or structure are caused by the crack happened from the defect existed at the inside of material. The properties of crack propagation and growth characteristic must be considered because there are many cases at which these cracks are densely existed. Therefore, this study investigates the fracture property due to the position of crack and hole inside the standard compact tension (C. T.) specimen. When the concentrated load is applied eccentrically at the standard C. T. specimen, the fracture mechanical behavior due to the existence or non-existence and the position of hole near crack is investigated. As the result of analysis study, model 3 (in case of the distance of 2mm on the horizontal direction between the end part and hole as the specimen model existed with one hole near the crack) has the maximum deformation, stress and deformation energy of the most values among three models. As the distance between the crack and hole inside the specimen becomes nearer, the maximum stress becomes higher in cases of three models. Apart from the number of holes, it is seen that the maximum stress becomes higher near the crack when the hole exists near the crack inside the specimen. If the hole inside the machine or the mechanical structure is punctured by using the result of this study, it is thought that the occurred breakage or breakdown can be prevented by reducing the fracture stress happened at the specimen.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.545-554
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• 2017

Birnessite is one of the dominant Mn (oxyhydr)oxide phases commonly found in soil and deep ocean environments. It typically occurs as nano-sized and poorly crystalline aggregates in the natural environment. It is well known that birnessite participates in a wide variety of bio/geochemical reactions as a reactive mineral phase with structural defects, cation vacancies, and mixed valences of structural Mn. These various bio/geochemical reactions control not only the fate and transport of inorganic and organic substances in the environment, but also the formation of diverse Mn (oxyhydr)oxides through birnessite transformation. This review assessed and discussed about the phase transformation of birnessite under a wide range of environmental conditions and about the potential geochemical factors controlling the corresponding reactions in the literature. Birnessite transformation to other types of Mn (oxyhydr)oxides were affected by dissolved Mn(II), dissolved oxygen, solution pH, and co-existing cation (i.e., $Mg^{2+}$). However, there still have been many issues to be unraveled on the complex bio/geochemical processes involved in the phase transformation of birnessite. Future work on the detail mechanisms of birnessite transformation should be further investigated.

• Journal of Hydrogen and New Energy
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• v.9 no.4
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• pp.151-160
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• 1998

The variation of the hydrogen-storage properties of Mg contained in the mechanically-allyed mixture with the weight percentage of nickel in the sample is investigated. The weight percentage of nickel transformed into the Mg2Ni phase, on the basis of the nickel weight, is highest in the Mg-10 wt.%Ni sample. For the first hydriding cycle, the effect of mechanical alloying on the hydriding rate of Mg is highest in the Mg-25 wt.%Ni sample. After activation, the effects of mechanical alloying and hydriding-dehydriding cycling on the hydriding rate of Mg are highest in the Mg-10 wt.%Ni sample. After sufficient hydriding-dehydriding cycling, the effects on the hydrogen-storage capacity of Mg are highest in the Mg-10 wt.%Ni sample. The effects on the hydriding and dehydriding rates of Mg are highest in the Mg-25wt.%Ni sample. Mg-25wt.%Ni, followed by Mg-10 wt.%Ni, is the optimum composition which has the best effects on the hydrogen-storage properties of Mg contained in the sample. The mechanical alloying and the hydriding-dehydriding cycling produce many defects, which can act as active nucleation sites, and increase the specific surface area, shortening the diffusion distance of hydrogen.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.57-64
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• 2018

Pre-eruptive intracoronal resorption (PEIR) is a developmental defect in the crown of a pre-eruptive tooth. The purpose of this study was to investigate the relationship between the size of the pre-eruptive buccal pit radiolucency, which is suspected as PEIR on a panoramic radiography, and the need for restoration after the eruption of a mandibular first molar. The experimental group included 35 mandibular first molars, in which lesions requiring definite restoration were observed during eruption. The control group consisted of 64 sound mandibular first molars after eruption. The sex, age, tooth position, tooth formation stage, size of the pre-eruptive buccal pit radiolucency, and restoration methods in the experimental group and control group were examined. Compared with the control group, the experimental group showed a statistically significant difference in the size of the buccal pit before eruption. The buccal pit size for predicting the need for restoration was further examined by receiver operating characteristic curve analyses, and the area under the curve was $0.813{\pm}0.047$. If radiolucency is observed at the buccal pit of the mandibular first molar before eruption, periodic observations and post-eruption examinations are required.

• Elastomers and Composites
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• v.48 no.3
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• pp.216-220
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• 2013

The phase separation in Wood Flour-Polymer Composite (WPC) was investigated and the reasons for change in mechanical properties with the content of wood flour were explored. The wood flour-polypropylene composite samples with different wood flour contents were prepared. From differential scanning calorimetry (DSC) thermograms of WPC samples, the trend of crystallinity and melting temperature ($T_m$) were analyzed. The crystallinity and melting temperature increased and then decreased as the content of wood flour increased. From these results, it was confirmed that at the low wood flour content the wood flours were dispersed into the polypropylene matrix but at the high wood flour content, the phase separation between polymer and wood flour phases appeared. The tensile strength of WPC samples was continuously decreased with the increase of wood flour content. At a low wood flour content, the low interfacial bonding and the decrease in crystallinity were the main reasons for the decrease in tensile strength with the increase of wood flour content. At a high wood flour content, the decrease in tensile strength resulted from the interfacial defects between the polymer and wood flour phases. The impact strength of the WPC sample showed the maximum behavior with the content of wood flour. At a low wood flour content, the impact strength was enhanced owing to the decrease in brittleness, which results from the decrease in crystallinity. At a high wood flour content, however, the impact strength decreased due to phase separation.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.145-181
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• 2013

General aviation is an integral part of civil aviation and involves the widest range of aviation segments except commercial aviation. Featured with different operational procedures and practices to satisfy the economic needs and safety requirements of a sovereign state, general aviation tends to be regulated by an individual state. The last three decades have seen exponential growth of commercial air transport in China, but its general aviation sector has remained disproportionally underdeveloped. With the deepening of the reform of low-altitude airspace, the sector is poised for a radical change and rapid growth. However, legislation governing general aviation activities in China is distorted causing inconsistency and confusions in their application and implementation. This paper aims to analyse China's prevailing legislation regulating general aviation activities. It first discusses the various definitions adopted by ICAO and its member states and reviews the development of general aviation in the US, EU, Australia and China. It then examines the sources of China's general aviation laws, e.g. Chicago Convention and its annexes, and Chinese domestic legislature which covers legislation, laws, directives, rules and procedures. The paper continues to analyse and establish the deficiencies of its prevailing legal framework by pointing out the following: variation of definitions in different regulations, inconsistency of principles in existing laws and regulations, legal vacuum concerning government subsidy, environment protection, safety and security, and other operational areas such as aerial club, sightseeing, and search and rescue. In this process, the paper argues that a coherent, consistent and systematic legal framework is required in order to ensure fair competition and safety for a healthy, progressive and sustainable general aviation growth. Suggestions for rectification and improvement are proposed.

• Journal of IKEEE
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• v.19 no.2
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• pp.186-192
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• 2015

This paper proposes an automatic generation technology of test case based on API in source code for software's quality improvement. The proposed technology is comprised of four processes which are analyzing source code by using the Doxygen open source tool, defining API specification by using analyzed results, creating test design, generating a test case by adapting Pairwise test technology. Analyzing source code by using the Doxygen open source tool is the phase in which API information in source code such as the API name, input parameter and return parameter are extracted. Defined API specification by using analyzed results is the phase where API informations, which is needed to generate test case, are defined as a form of database by SQLite database on the basis of extracted API information. Creating test design is the phase in which the scenario is designed in order to be composed as database by defining threshold of input and return parameters and setting limitations based on the defined API. Generating a test case by adapting Pairwise test technique is the phase where real test cases are created and changed into database by adapting Pairwise technique on the base of test design information. To evaluate the efficiency of proposed technology, the research was conducted by begin compared to specification based test case creation. The result shows wider test coverage which means the more cases were created in the similar duration of time. The reduction of manpower and time for developing products is expected by changing the process of quality improving in software developing from man-powered handwork system into automatic test case generation based on API of source code.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.96-96
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• 1999

CdTe는 일반적으로 광전 소자나 Xtjs 및 λ선 감지 소자로서 많은 연구가 되어지고 있는 물질이다. 특히 적외선 감지 소자로 쓰이고 있는 HgCdTe 물질의 기판으로서도 많은 연구가 진행되고 있다. 이러한 여러 가지 목적으로 사용함에 있어서 CdTe 내에 가지고 있는 여러 가지 불순물에 의한 영향으로 각종 결함밴드들이 형성됨으로서 소자로서의 응용에 많은 지장을 주고 있다. 이러한 이유로 여러 가지 방법으로 불순물 및 결합에 의한 준위에 관한 연구들이 진행되고 있다. 본 실험에서는 MBE 법으로 성장된 In 도핑된 CdTe 박막의 광학적 성질을 관찰하기 위하여 수소화 및 열처리를 하여 PL 법을 이용하여 관찰하여 보앗다. 열처리는 Cd 분위기의 50$0^{\circ}C$에서 5시간 동안 수행하였으며 수소화는 rf plasma 장치를 이용하여 8$0^{\circ}C$에서 50mW/c2의 출력으로 1시간동안 수행하여 주었다. 열처리한 시료의 경우 PL 신호는 갓 성장한 시료와 비교하여 깊은 준위에 관련된 신호들만 변화가 있었을뿐 그리 큰 변화가 있지는 않았다. 그러나 수소화시킨 시료의 경우 전체적으로 피크의 크기가 5배정도 감소하는 것을 볼 수 있었는데 이것은 수소에 의하여 passivation된 효과로 볼 수 있다. 정량적인 passivation 효과를 보기 위하여 온도의존성 PL 측정을 하여 보았다. 측정에서 관측된 (D,h) emission lines의 FWHM을 비교하여 본 결과 FWHM 온도가 증가함에 따라 선형적으로 증가하는 것이 아니라 급격한 증가를 q이는 구간을 관착할 수 있었다. 이것은 CdTe내에 존재하는 전하를 띠고 있는 주게와 받게의 결합의 결과로 나타나는 현상으로 보여진다. 이러한 결과를 통하여 얕은 준위에 있는 주게 불순물의 농도를 계산해 보았고 Hall 측정을 얻은 결과와 비교하여 보았다.판단된다. 따라서 이 기술은 기존의 광소자 제작을 위한 IFVD 방법의 문제점을 해결할 뿐만 아니라 결정 재성장 없이 도일한 기판상에 국부적으로 상이한 bandgap 영역을 만들 수 있기 때문에 광소자 제작에 적극 이용될 수 있다.나지 않았으며 BST 박막에서는 약 1.2V의 C-V이력현상이 보였다.를 이용하였으며, 이온주입후 열처리 온도에 따른 활성화 정도의 관찰을 위하여 4-point probe와 Hall measurement를 이용하였다. 증착된 다결정 SiGe의 두게를 nanospec과 SEM으로 분석한 결과 Gem이 함량이 적을 때는 높은 온도에서의 증착이 더 빠른 증착속도를 나타내었지만, Ge의 함량이 30% 되었을 때는 온도에 관계없이 일정한 것으로 나타났다. XRD 분석을 한 결과 Peak의 위치가 순수한 Si과 순수한 Ge 사이에 존재하는 것으로 나타났으며, ge 함량이 많아짐에 따라 순수한 Ge쪽으로 옮겨가는 경향을 보였다. SEM, ASFM으로 증착한 다결정 SiGe의 morphology 관찰결과 Ge 함량이 높은 박막의 입계가 다결정 Si의 입계에 비해 훨씬 큰 것으로 나타났으며 근 값도 증가하는 것으로 나타났다. 포유동물 세포에 유전자 발현벡터로써 사용할 수 있음으로 post-genomics시대에 다양한 종류의 단백질 기능연구에 맡은 도움이 되리라 기대한다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품 개발에 따른 새로운 수요 창출과 수익률 향상, 기존의 기능성 안료를 나노(nano)화하여 나노 입자를 제조, 기존의 기능성 안료에 대한 비용 절감 효과등을 유도 할 수 있다. 역시 기술적인 측면에서도 특수소재 개발에 있어 최적의 나노 입자 제어기술 개발 및 나노입자를 기능성 소재로 사용하여 새로운 제품의 제조와 고압 기상 분사기술의 최적화에 의한 기능성 나노 입자 제조 기술을 확립하고 2차 오염 발생원인 유

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.238-240
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• 2006

네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc