• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.9
• /
• pp.53-59
• /
• 2006

Need for agile satellite increases for performing various mission due to increase of satellite image applications and users. In high resolution satellite TDI (time delay and integration) method is adopted in order to improve SNR. But image quality can be degraded by satellite maneuver. In this paper requirements for remote sensing in high resolution satellite with agility are extracted and an approach to operate the agile satellite to perform the missions are proposed. The proposed approach in this paper will be applicable to system level design and analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.330-337
• /
• 2002

The HANARO seismic monitoring system is classified as non-nuclear safety(NNS), seismic category I, and quality class T The seismic monitoring system installed at the instrument room consists of five field sensors and one monitoring cabinet. The field sensors are composed of three triaxial accelerometers which installed at base slab, free field and overhead crane support respectively, a seismic trigger and a seismic switch at base slab. The most parts of analog system except field sensors are not produced any more, the improvement of the system is to be needed. The analog system with magnetic tape recorder is not only out-of-date model but dependent upon foreign technology. So it is difficult to get the spare parts and the cost to buy them is increased. Therefore we have improved the analog seismic monitoring system into a new digital seismic monitoring analysis system(SMAS) except five field sensors. After the installation of the new SMAS, we have carried out the site acceptance test(SAT) to confirm the field functions. The results of SAT satisfy the requirements of the fabrication technical specification. This new SMAS is operating at HANARO instrument room to acquire and analyse the signal of earthquake.

• Journal of the Optical Society of Korea
• /
• v.10 no.1
• /
• pp.1-10
• /
• 2006

Optical transparency and high diffraction efficiency are two essential factors for high performance of the photopolymer. Optical transparency mainly depends on the miscibility between polymer binder and photopolymerized polymer, while diffraction efficiency depends on the refractive index modulation between polymer binder and photopolymerized polymer. For most of organic materials, the large refractive index difference between two polymers accompanies large structural difference that leads to the poor miscibility and thus poor optical quality via light scattering. Therefore, it is difficult to design a high-performance photopolymer satisfying both requirements. In this work, first, we prepared a new phase-stable photopolymer (PMMA) with large refractive index modulation and investigated the optical properties. Our photopolymer is based on modified poly (methyl methacrylate) as a polymer binder, acryl amide as a photopolymerizable monomer, triethanolamine as initiator, and yellow eosin as a photosensitizer at 532 nm. Diffraction efficiency over 85% and optical transmittance over 90% were obtained for the photopolymer. Second, Organic-inorganic nanocomposite films were prepared by dispersing an aromatic methacrylic monomer and a photo- initiator in organic-inorganic hybrid sol-gel matrices. The film properties could be controlled by optimizing the content of an organically modified silica precursor (TSPEG) in the sol-gel matrices. The photopolymer film modified with the organic chain (TSPEG) showed high diffraction efficiency (> 90%) under an optimized condition. High diffraction efficiency could be ascribed to the fast diffusion and efficient polymerization of monomers under interference light to generate refractive index modulation. The TSPEG modified photopolymer film could be successfully used for holographic memory.

• Journal of the Korean Professional Engineers Association
• /
• v.38 no.1
• /
• pp.44-51
• /
• 2005

A recent study conducted by KOTI reported that regional and urban read congestion costs in Korea are continually rising in the ranges between 3.1% thru 4.1% of GDP in the every respective year during the past 10 years. The report explicates that the congestion problem has motivated sharp raise of the logistics expenditure from 4.4% of GDP in the year of 1998 to 16% in the year of 2003. Even though, the government has allotted annual budget in the ranges between 2.7% and 3.7% of GDP to the SOC investment for the consecutive years of past decade, the amounts are however far less and insufficient to meet with social requirements and its demands. The cost of logistics has been excessively went up much higher rate than that of other industries and that of 9.6% in Japan and United States respectively It is obvious that the high logistics cost could be a detrimental factor to fierce emulation with others in the global trade market. Therefore it is an essential matter to eliminate or exclude all the probable sources that might cause or create extra costs on logistics. In consideration of such situation in Korea, the SOC investment with private capital could be a best cogitable scheme to acquire its prompt demand solutions and stimulate the emulation ability in the international trade market what's more betterment for all of our quality life in the near future.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.11
• /
• pp.219-229
• /
• 2020

The study investigates the factors affecting the profitability of listed commercial banks in Vietnam. Survey data for this research were collected from 10 Vietnamese listed commercial banks for the period from 2008 to 2018. In the study, we have built a model of econometric regression with the dependent variable being listed commercial banks' profitability results measured through ROA. The research methods used include descriptive statistics, IV regression and OLS regression analysis, and the authors carried out the model verification with Stata 14 software. The results showed that operating efficiency, loans size, retail loans ratio, state ownership, inflation rate, and GDP growth are factors that have a positive impact on profitability On the other hand, variables such as capital size, credit risk, liquidity risk, bank size, and revenue diversification are statistically insignificant; hence, these variables are not statistically adequate to indicate the influence of those independent variables to banks' profitability. The findings of this study suggest that the quality of assets should be considered in the context that bad debt risks come from lending heavily to the real estate sector. Meeting Basel II's capital compliance requirements is relatively difficult for small listed commercial banks compared to bigger listed commercial banks in Vietnam.

• Journal of KIISE:Information Networking
• /
• v.28 no.3
• /
• pp.417-425
• /
• 2001

Since First-Come-First-Served discipline makes it difficult to satisfy the diverse quality of scrvicc(QoS) requirements for each c-oonection, traffic isolation has been proposed for guaranteeing the desired QoS through explicit bandwidth allocation to each virtual connection(VC) in A TM networks. For this purpose, we propose a rate-controlled cell multiplexer using a simple "periodic token-based regulator" per- Vc. The proposed multiplexer realizes VC isolation, while still operating work'||'&'||'not;conservingly. We first discuss its major properties, and then examine its features with respect to the characteristics of the output traffic streams and the traffic isolation of individual VC's, by simulation.n.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.5
• /
• pp.614-620
• /
• 2014

This study was conducted to evaluate menu pattern and nutritional contents of snack menus provided by child care information centers in Seoul. Snack menus during March 2013 (morning snack : 125 cases, afternoon snack : 100 cases), including information on portion size, were collected from five child care information centers, after which the number of menu items, menu patterns, and nutritional contents were analyzed. About two-thirds of total snack menus included two menu items. There were significant differences in service time (morning & afternoon snacks). 'Beverage+Food' pattern (66.7%) was the most commonly used; 'Beverage' pattern was significantly higher in morning snacks (10.4%) than in afternoon snacks (1.0%). Morning and afternoon snacks provided 124.5 and 170.6 kcal of energy and 116.4 and 90.9 mg of calcium, respectively, which are 8.9% and 12.2% as well as 19.4%, and 15.2% of children's daily energy and calcium requirements. To improve the quality of food and nutrition offered to children through snacks at child carre centers, a more detailed snack menu plan as well as nutritional guidelines for institutions should be developed.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.92-96
• /
• 2000

In this paper, we propose a call admission control(CAC) scheme fer the mixed voice/data DS-CDMA systems and analyze the Er-lang capacity under the proposed CAC scheme. Voice and data traffics require different system resources based oil their Quality of Service(QoS) requirements. In the proposed CAC scheme, some system resources are reserved exclusively for handoff calls to have high priority Over new calls. Additionally the queueing of both new and handoff data traffics that are not sensitive to delay is allowed. Ar a performance measure for the suggested CAC scheme. Erlang capacity is utilized. For the performance analysis, a four-dimensional Markov chain model is developed. Erlang capacity of a practical IS-95B type system depicts, and optimum values of system parameters such as the number of reservation channels and queue lengths are found with respect to Erlang capacity. Finally, it is observed that Erlang capacity is improved more than two times by properly selecting the system parameters with the proposed CAC scheme.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.463-468
• /
• 2016

The overall performance of multiuser systems significantly depends on how effectively and fairly manage resources shared by them. The efficient resource management strategies are even more important for multimedia users since multimedia data is delay-sensitive and massive. In this paper, we focus on resource allocation based on a game-theoretic approach, referred to as Nash bargaining solution (NBS), to provide a quality of service (QoS) guarantee for each user. While the NBS has been known as a fair and optimal resource management strategy, it is challenging to find the NBS efficiently due to the computationally-intensive task. In order to reduce the computation requirements for NBS, we propose an approach that requires significantly low complexity even when networks consist of a large number of users and a large amount of resources. The proposed approach linearizes utility functions of each user and formulates the problem of finding NBS as a convex optimization, leading to nearly-optimal solution with significantly reduced computation complexity. Simulation results confirm the effectiveness of the proposed approach.

• Korean Institute of Interior Design Journal
• /
• v.26 no.6
• /
• pp.126-134
• /
• 2017

Since public rental housings (social housings) in Korea are extremely standardized and uniformed, a variety of needs of residents for their housing are hardly satisfied. Public rental housing conditions, its low quality and size limitations regardless of residents type and needs resulted into negative images of social housing and social discriminations. Therefore there is a growing demand for alternative housing options in terms of diversification of social housing design with consideration for changing households and housing requirements. The purpose of this study to investigate some housing design guidelines, to analyze layout of building complex, community designs, household units and characteristics, overall design characteristics (sustainable design features, facade design, window and balcony composition, color and materials) and to provide some design suggestions for social housing. Design guidelines are classified into site planning and building layouts, residential building and household units, and performance of housing. Community facilities and their design features provide uniqueness of the public residence. Overall housing size of foreign cases is bigger than the domestic cases. Narrow shape of household units are more dominant in Korean public rental housing. More various shape and forms are found in facade and window design in foreign cases. Some design suggestion are provided for more diverse housing units and design for public rental housing in Korea.