• 한국항공우주학회지
• /
• 제43권11호
• /
• pp.998-1007
• /
• 2015

방사형 인공위성 경우, 관성곱이 커서 단일 입 출력 가정이 불가능하기 때문에 고전적 제어기 설계방법을 사용하기 어렵다. 본 논문에서 현대 제어 이론인 $H_{\infty}$ 제어기 설계이론을 사용하여 방사형 인공위성의 자세 제어기 설계를 수행하였다. 설계 알고리즘으로 보다 안정적인 LMI 방법이 사용되었고, 설계 결과에 대한 안정성과 성능에 대한 강건성 해석을 위해 ${\mu}$-해석 방법이 적용되었다. 설계 결과, 일반적인 경우와 다르게 제어기가 포함되지 않은 개루프보다 제어기가 포함된 개루프의 cross-over frequency가 더 낮게 설계되는 것이 관측되었다. 즉 상대적으로 큰 관성곱 영향 때문에 단지 weighting 함수 조정으로 위성 기동성을 증가시키는데 한계가 있는 것으로 해석된다. ${\mu}$-해석을 위해 +/-5%의 관성모멘트 변화를 가정하였다. 안정성 및 성능에 대한 강건성 해석결과, +/-7% 관성모멘트 변화까지 시스템 안정성 및 성능이 보장됨이 확인되었고, 관성곱 변화보다 주관성모멘트 변화가 안정성 및 성능 저하에 더 영향을 주는 것으로 확인되었다.

• Nuclear Engineering and Technology
• /
• 제42권5호
• /
• pp.576-581
• /
• 2010

KAERI (Korea Atomic Energy Research Institute) fabricated MOX (Mixed Oxide) fuel pellets as a cooperation project with PSI (Paul Scherrer Institut) for an irradiation test in the Halden reactor. The MOX pellets were fitted into fuel rods that included instrumentation for measurement in IFE (Institutt for Energiteknikk). The fuel rods were assembled into the test rig and irradiated in the Halden reactor up to 50 MWd/kgHM. The irradiated fuel rods were transported to the IFE, where ceramography was carried out. The fuel rods were cut transversely at the relatively higher burn-up locations and then the radial cross sections were observed. Micrographs were analyzed using an image analysis program and grain sizes along the radial direction were measured by the linear intercept method. Radial cracks in the irradiated MOX were observed that were generally circumferentially closed at the pellet periphery and open in the hot central region. A circumferential crack was formed along the boundary between the dark central and the outer regions. The inner surface of the cladding was covered with an oxide layer. Pu-rich spots were observed in the outer region of the fuel pellets. The spots were surrounded by many small pores and contained some big pores inside. Metallic fission product precipitates were observed mainly in the central region and in the inside of the Pu spots. The average areal fractions of the metallic precipitates at the radial cross section were 0.41% for rod 6 and 0.32% for rod 3. In the periphery, pore density smaller than 2 ${\mu}m$ was higher than that of the other regions. The grain growth occurred from 10 ${\mu}m$ to 12 ${\mu}m$ in the central region of rod 6 during irradiation.

• 통합자연과학논문집
• /
• 제6권1호
• /
• pp.34-38
• /
• 2013

Tributyltin hydride ($n-Bu_3SnH$), an endocrine disruptor, was slowly polymerized by the group 4 ${Cp^{\prime}}_2TiCl_2/N$-selectride (Cp' = $C_5H_5$, Cp; $Me-C_5H_4$, Me-Cp; $Me_5C_5$, $Cp^*$) catalyst combination to give two phases of products: one is an insoluble cross-linked solid, polystannane in 3-25% yield as minor product via disproportionation/dehydrocoupling combination process, and the other is an oil, hexabutyldistannane in 65-90% yield as major product via simple dehydrocoupling process. Disproportionation/dehydrocoupling process first produced a low-molecular-weight oligostannane possessing partial backbone Sn-H bonds which then underwent an extensive cross-linking reaction of backbone Sn-H bonds, resulting in the formation of an insoluble polystannane. The disproportionation/dehydrocoupling of a tertiary hydrostannane mediated by early transition metallocene/inorganic hydride is quite unusual and applicable.

• 한국의상디자인학회지
• /
• 제21권3호
• /
• pp.37-53
• /
• 2019

The purposes of this study were to investigate Chinese female consumers' shopping orientation and clothing shopping behaviors on the internet and to find the differences in internet shopping behaviors of consumer groups segmented by clothing shopping orientation. The subjects were 417 women in their 20s and 30s from the Gillim Province, China. The research method was a survey, and the questionnaire consisted of a clothing shopping orientation subscale, clothing, their shopping behaviors via the internet, and the subjects' demographic characteristics. For data analysis, a frequency analysis, a cross-tab analysis, a factor analysis, a cluster analysis, ANOVA, and Duncan's multiple range test were performed. The results of this study were as follows. The clothing shopping orientation was derived using five factors (trend pursuit, pleasure pursuit, brand pursuit, economic pursuit, and convenience pursuit). Chinese female consumers were classified into three groups (hedonic group, ambivalent group, and practical group) by clothing shopping orientation. These three groups showed many significant differences in their clothing shopping behaviors on the internet. The hedonic group preferred the specialty and cross-border shopping malls, and considered product quality and trend as their main purchase motives. The ambivalent group considered the convenience of the purchase and trend as important motives as compared to the other groups, and they use more various product selection criteria. The practical group considered low price and convenience and the search simplicity of various products as major purchase motives. In addition, the hedonic and ambivalent groups had a higher purchase satisfaction and purchase intention from internet shopping than the practical group. This study suggested that clothing shopping orientation is one of the useful segmentation variables and fashion marketers needed to establish differentiated marketing strategies for each consumer group that is segmented by clothing shopping orientation.

• 한국의상디자인학회지
• /
• 제25권3호
• /
• pp.127-141
• /
• 2023

The purpose of this study is to develop a textile pattern design using the columnar joints motif and a Tyvek fashion clutch bags using it. As a research method, first, through a literature review, columnar joint and Tyvek are understood, and design cases were considered. Second, through a survey, the purchase perception and design preference of columnar joints cultural products were analyzed. Third, based on the results of the survey on color and print, the pattern design for each type of columnar joint were developed, and the uv-printed Tyvek clutch bag was developed. The results of this study are as follows. First, the reason why the public was not attracted to the purchase of cultural products was dissatisfaction with practicality, price adequacy, and aesthetics. Therefore, it was analyzed that quality, practicality, price, carry-on storage, collection value, and casualness, as well as aesthetic design were important factors for purchasing factors pursued by consumers. Second, consumers preferred small goods the most for cultural products, and they pursued the use of colorful and contrasting colors, modern and geometric patterns, and eco-friendly materials, such as Tyvek. Third, columnar joint can be classified into three cross sections and four arrangements. The design unit of the columnar joint could be expressed as a hexagonal column, and 12 different pattern designs could be developed according to the cross sections and arrangements type. In addition, it was found that it was easy to produce fashion products suitable for the sensibility of modern people by utilizing Tyvek materials.

• Journal of Pharmaceutical Investigation
• /
• 제27권4호
• /
• pp.323-329
• /
• 1997

Ipriflavone is non-hormonal antiosteoporotic drug which inhibits bone resorption by reducing recruitment and/or differentiation of osteoclasts, and stimulates proliferation and differentiation of osteoblast, and also enhances calcitonin secretion in the presence of estrogen. Although some kinds of immediately-released preparation of ipriflavone are available in commercial market, in present study, we tried to formulate sustained-release tablet using coating method with hydrophobic and hydrophilic coating materials. In vitro dissolution test was applied to evaluate sustained-release patterns of several test preparations (Test tablet A, B and C) designed using different preparation method or different compositions. From the results of dissolution test, test tablet A which showed suitable dissolution profile was selected as the candidate of new product. Pharmacokinetic evaluation of test drug, ipriflavone sustained-release tablets, was conducted in 6 beagle dogs weighing $11.5{\pm}0.5\;Kg$ compared with $Theobon^{\circledR}$ tablet, immediately-released tablet (Kukjae Pharm. Co.) as reference drug. Two products were randomly administered to 6 beagle dogs, and after 1 week, cross-over study was conducted. From the present study, AUC and $T_{max}$ of test product were significantly different from those of reference product (p<0.05), respectively$(AUC\;:\;3646.28{\pm}472.56\;vs\;3646.28{\pm}472.56\;ng{\cdot}hr/ml,\;T_{max}\;:\;4.33{\pm}1.03\;vs\;1.42{\pm}0.38\;hr)$. But $C_{max}$ was not significantly different between two products (p>0.05) $(\;512.52{\pm}48.18\;vs\;443.97{\pm}140.53\;ng/ml)$. From the results of pharmacokinetic evaluations, it was noted that absorption amount of test product was increased, but absorption rate was delayed and $C_{max}$ of two products were not changed. And it was concluded that redesign of the sustained-release preparation which has a lower content of iprifavone rather than test tablet A must be considered.

• 한국산학기술학회논문지
• /
• 제10권9호
• /
• pp.2440-2450
• /
• 2009

본 연구의 목적은 첫째, 프로세스 기획 역량이 신제품 개발 성과에 미치는 영향을 검증하고자 한다. 특히, 프로세스 기획 역량이 개별적인 프로젝트의 성과가 아닌 제품군 전체의 성과에 미치는 영향력을 검증하였다. 둘째, 개발 역량 간 상호작용이 신제품 개발 성과에 미치는 영향을 살펴보았다. 본 연구는 국내 103개 제조기업으로부터 수집한 설문응답 분석에 기초하였다. 제품군 개발은 크게 두 가지 유형의 프로젝트 (플랫폼 및 파생제품 개발)으로 구분된다. 본 연구에서는 두 가지 프로젝트 유형 중, 제품군 성공의 중심적인 역할을 수행하는 플랫폼 제품을 중심으로 분석하였다. 본 연구결과 제품군의 기술적 성과 및 상업적 성과 향상을 위해 우수한 프로세스 기획 역량이 필요함을 보여준다. 또한 기술개발 역량은 기술적 성과에 직접적으로 유효한 영향을 미치지는 않지만, 프로세스 기획 역량과 상호작용을 통해 기술적 성과 향상에 영향을 미치는 것을 확인하였다.

• 수면정신생리
• /
• 제27권2호
• /
• pp.51-55
• /
• 2020

본 논문에서는 국내 수면산업의 발전을 위해 수면제품 실증의 국내외사례와 평가 방법들에 대해 리뷰해 보았다. 국외에는 실증을 위한 회사나 단체가 비교적 체계적으로 제품을 검증하려고 하고 있지만 기관에 따라 다소 다른 방법을 활용하고 있었고, 표준화된 실증가이드가 확립되지는 않고 있었다. 국내의 경우는 객관적인 실증을 포함하는 평가는 사실상 전무하였다. 수면제품 실증을 위한 수면-각성 평가의 평가는 제품 자체에 관한 전문가 평가 및 사용자의 효과성 평가가 필요할 것이며 사용자 대상 평가는 주관적, 객관적 수면-각성 평가 및 일주기 리듬 평가 방법이 활용될 수 있겠다. 보다 정확한 검증을 위해 무작위 배정법, 대조 용품 활용법, 교차실험설계 등의 디자인도 활용될 수 있다.

• Asia Marketing Journal
• /
• 제15권3호
• /
• pp.79-95
• /
• 2013

New product innovation is a process of embodying new knowledge in a product and technology licensing is getting popular as a means to innovations and introduction of new product to the market in today's competitive global market environment. Incumbents often rely on technology licensing to access new product opportunities created by other firms. Prior research has examined various aspects of technology licensing agreements such as specific contract terms of licensing agreements, e.g., distribution of control rights, exclusivity of licensing agreements, cross-licensing, and the scope of licensing agreements. This study aims to provide answers to an important, but under-researched question: why do some incumbents initiate more licensing agreement for exploratory learning while others do it for exploitative learning along the innovation process? We attempt to extend our knowledge of licensing agreements from an organizational learning perspective. Technology licensing as a specific form of interfirm linkages can be initiated with different learning objectives along the process of new product innovation. The exploratory stages of the innovation process such as discovery or research stages involve extensive searches to create new knowledge or capabilities, whereas the exploitative stages of the innovation process such as application or test stages near the commercialization are more focused on developing specific applications or improving their efficiency or reliability. Thus, different stages of the innovation process generate different types of learning and the resulting technological resources. We examine when incumbents as licensees initiate more licensing agreements for exploratory learning objectives and when more for exploitative learning objectives, focusing on two factors that may influence a firm's formation of exploratory and exploitative licensing agreements: 1) its past radical and incremental innovation experience and 2) its internal investments in R&D and marketing. We develop and test our hypotheses regarding the relationship between a firm's radical and incremental new product experience, R&D investment intensity and marketing investment intensity, and the likelihood of engaging in exploratory and exploitive licensing agreements. Using data collected from various secondary sources (Recap database, Compustat database, and FDA website), we analyzed technology licensing agreements initiated in the biotechnology and pharmaceutical industries from 1988 to 2011. The results of this study show that incumbents initiate exploratory rather than exploitative licensing agreements when they have more radical innovation experience and when they invest in R&D activities more intensively; in contrast, they initiate exploitative rather than exploratory licensing agreements when they have more incremental innovation experience and when they invest in marketing activities more intensively. The findings of this study contribute to the licensing and interfirm cooperation studies. First, this study lays a foundation to understand the organizational learning aspect of technology licensing agreements. Second, this study sheds lights on how a firm's internal investments in R&D and marketing are linked to its tendency to initiate licensing agreements along the innovation process. Finally, the findings of this study provide important insight to managers regarding which technologies to gain via licensing agreements. This study suggests that firms need to consider their internal investments in R&D and marketing as well as their past innovation experiences when they initiate licensing agreements along the process of new product innovation.

• Parasites, Hosts and Diseases
• /
• 제58권3호
• /
• pp.267-278
• /
• 2020

The heterogeneity and complexity of malaria involves political and natural environments, socioeconomic development, cross-border movement, and vector biology; factors that cannot be changed in a short time. This study aimed to assess the impact of economic growth and cross-border movement, toward elimination of malaria in Yunnan Province during its pre-elimination phase. Malaria data during 2011-2016 were extracted from 18 counties of Yunnan and from 7 villages, 11 displaced person camps of the Kachin Special Region II of Myanmar. Data of per-capita gross domestic product (GDP) were obtained from Yunnan Bureau of Statistics. Data were analyzed and mapped to determine spatiotemporal heterogeneity at county and village levels. There were a total 2,117 malaria cases with 85.2% imported cases; most imported cases came from Myanmar (78.5%). Along the demarcation line, malaria incidence rates in villages/camps in Myanmar were significantly higher than those of the neighboring villages in China. The spatial and temporal trends suggested that increasing per-capita GDP may have an indirect effect on the reduction of malaria cases when observed at macro level; however, malaria persists owing to complex, multi-faceted factors including poverty at individual level and cross-border movement of the workforce. In moving toward malaria elimination, despite economic growth, cooperative efforts with neighboring countries are critical to interrupt local transmission and prevent reintroduction of malaria via imported cases. Cross-border workers should be educated in preventive measures through effective behavior change communication, and investment is needed in active surveillance systems and novel diagnostic and treatment services during the elimination phase.