• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.201-208
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• 2013

This paper is a study of an empirical design of an open-ended coaxial cavity resonator. It can be done by using the radius of the inner conductor, the inner radius and the length of the resonator. However, the basic coaxial transmission -line theory can be seen that the characteristics of the resonant frequency and the Q value are varied by the change of length, regardless of the value of radius of the inner conductor and inner radius of the resonator. We find out the impact of radius of the inner conductor, inner radius of the resonator and the length of the resonator parameter and propose the optimized empirical resonator design method by reducing the error between the theoretical value and the design value. Based on the simulation, several resonators are fabricated by the size of 14 mm for the radius of inner conductor, 2 mm, 5 mm, 10 mm respectively for the inner radius of resonator, and 8.5 mm for the length of the resonator. The resonant frequencies of the produced resonators were measured at 6.1, 5.7, 6.5 GHz respectively. According to the result of simulation and measurement, we know that we can design the relatively exact open-ended coaxial cavity resonator by applying the basic coaxial transmission-line theory directly when the length of the resonator is less than 10 mm, and adding the correction factor of 0.5 GHz to the calculated resonant frequency in case of more than 10 mm of the length of the resonator.

• Journal of Korea Water Resources Association
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• v.47 no.5
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• pp.483-490
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• 2014

The design procedures for a biological reactor and a secondary settling tank (SST) of an activated sludge system are based on the steady state design method (Ekama et al., 1986; WRC, 1984) and the 1-D flux theory design method (Ekama et al., 1997), respectively. This study combined both of the design procedures, to determine the optimum sludge concentration in the reactor and the best design with the lowest cost. The best design of the reactor volume and the SST diameter at the optimum sludge concentration were specified with varying wastewater and sludge characteristics, temperature, sludge retention time (SRT) and peak flow rate. The effects of the influent wastewater characteristics, such as substrate concentration and unbiodegradable particulate fraction, were found to be considerable, but the effect of unbiodegradable soluble fraction was to be negligible. The effects of sludge settling characteristics, were also significant. SRT, as an operating parameter, was found to be an important factor for determining the optimum sludge concentration. However, the effect of temperature was found to be small. Furthermore, for designing a large scale wastewater treatment plant, the number of reactors or SSTs could be estimated, by dividing the total reactor volume or SST area. The new combined design procedure, proposed in this research, will be able to allow engineers to provide the best design of an activated sludge system with the lowest cost.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.109-112
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• 2008

In this study, Assessment of bond property of HSC with the rate of Blust-furnace(0, 12, and 25 percent by weight cement) and Evaluation of the relationship of the compressive strength coefficient (${\beta}$) between compressive strength with 40${\sim}$120MPa were performed. Design and Test of Bond specimens were carried out based on the ASTM C-234. Test results are follows, most specimens showed that the splitting failure in all specimens, except for B-40 series which showed that the pull-out failure. For the B-40 Series, the relation of compressive strength versus bond stress has well converged that of the proposed equation with the variation(${\beta}$=2/3) in UCB/E.E.R.C-83. The crack strength of concrete in splitting was proportioned to the compressive strength of concrete, and was the highest on the contents of blast furnace slag to 12 percent by weight of cement in each series, except for B-60 series. In the relation of admixture replacement rate versus maximum bond stress, The maximum bond stress was the highest in 12 percent by weight of cement according to less than 40MPa, and was the highest in 25 percent by weight of cement according to 80MPa.

• Journal of the Korean Electrochemical Society
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• v.1 no.1
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• pp.33-39
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• 1998

To AC impedance study was performed in this study on the interfacial reaction between organic electrolyte and amorphous tungsten oxides thin film, cathodically coloring oxide, prepared by e-beam evaporation method in the 1 M $LiClO_4/PC$ organic solution. The electrochemical reactions at the interface were analyzed by the transient method and the complex impedance spectroscopy. The impedance spectrums showed that the electro-chemical intercalation of lithium cations was consisted of the following three steps; the first step, the charge transfer reaction of lithium cation at the interface between amorphous tungsten oxides thin film and the organic electrolyte, the second step, the adsorption of lithium atom on the surface of amorphous tungsten oxides thin film, and then the third step, the absorption and the diffusion of lithium atom into amorphous tungsten oxides thin layer. The bleaching and the coloring characteristics of amorphous tungsten oxides thin film were explained in terms of thermodynamic and kinetic variables, the simulated $R_{ct},\;C_{dl},\;D$ and $\sigma_{Li}$ by CNLS fitting method. Especially it was found that the limiting values of electrochromic reaction were the molar ratio of lithium, y=0.167 and the electrode potential, E=2.245 V (vs. Li).

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.837-840
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• 2008

This study was achieved experiment to evaluate effect on fluidity and strength development ratio by slag replacement ratio to $40{\sim}100MPa$ HSC(High Strength Concrete) containing blast furnace slag(GGBS) and fly-ash(FA). Also it was suggested that most suitable replacement ratio of GGBS is effect by strength. The mix plan of concrete used in an experiment was used to the GGBS replacement ratio of 0, 12, 25% as the cement materials, and fly ash was used equally by replacement ratio 15%. According to test results, for use GGBS with fly ash as binder, slump of GGBS replacement ratio 25% is the most superior in 40MPa series, and appeared by thing which slump flow of GGBS 12% is the most superior in 60, 80MPa's series. The other side, was expressed that fluidity is excellent by FA replacement ratio 15% in 100MPa series. In the case of compressive strength 40MPa, it was exposed that the strength revelation is effect in until the GGBS principal parts ratio increases by replacement ratio 25%. Also, it was exposed that GGBS mixing ratio more than replacement ratio 25% is not since fitness in high strength concrete more than 100MPa.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1129-1136
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• 2001

This study was to investigate the suitability of six domestic wheat cultivars for the Korean-style steamed bread made under optimal conditions. Six wheat flours milled from cultivars of Greu, Kumgang, Eunpa, Taptong Kobun, and Allgreu contained 13.8, 13.7, 13.7, 13.0, 11.7, 11.0% of protein. Control bread was made from blend (protein 10.5%) of 50% high strength and 50% low strength wheat flours milled from imported wheats. The volume of steamed bread made from Kumgang was highest followed by Eunpa, Tapdong, Kobun, Greu, control bread, Allgreu. Especially, the bread qualities of Kumgand and Kobun were superior to the control bread, showing better surface characteristics such as smoothness, glossiness, and whiteness, better shapes and desirable texture. Domestic wheat flours, having medium strength with high protein content above 13.0% were suitable for steamed bread except for Greu. Volumes of steamed bread made from domestic wheat flours were correlated with protein and ash content, flour color (L value), farinograph dough development time and stability, whereas spread ratio, total bread score and overall acceptability were correlated with farinograph dough stability It is concluded that flour quality is more important factor than protein content when domestic wheat flours are chosen for Korean-style steamed bread

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.1
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• pp.66-72
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• 2000

The behavior of nucleation and crystallization in the $Li_2O_3-SiO_2$ glass heat-treated at different condition under the conventional and microwave processing was studied by differential thermal analysis (DTA), X-ray diffractometry (XRD), optical microscopy (OM), and electrical conductivity measurement. Nucleation temperature and temperature of maximum nucleation rate in both conventionally and microwave heat-treated samples were 460~$500^{\circ}C$ and $580^{\circ}C$, respectively. It was expected that the probability for bulk crystallization increased in microwave heat-treated sample, compared to conventionally heat-treated one. Degree of crystallization increased with increasing crystallization temperature in both conventionally and microwave heat-treated samples. However, pattern of crystallization growth under microwave processing appeared to be quite different from that under the conventional one due to its internal or volumetric heating. Electrical conductivity of conventionally and microwave heat-treated samples were 1.337~2.299, 0.281~~$0.911{\times}10^{-7}\Omega {\textrm}{cm}^{-1}$, respectively.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.553-559
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• 2009

One of zeolitic imidazolate framework materials (ZIF), ZIF-8, has been synthesized with microwave irradiation and conventional electric heating at $140{\sim}180^{\circ}C}$. ZIFs are porous crystalline materials and are similar to metal organic framework (MOF) materials because both ZIFs and MOFs are composed of both organic and metallic components. ZIFs are very stable and similar to zeolites because ZIFs have tetrahedral networks. ZIF-8, with a decreased crystal size, can be synthesized rapidly with microwave irradiation. The microwave synthesis of ZIF-8 is completed in 4 h at $140{^{\circ}C}$ and the reaction time is decreased by about 5 times compared with the conventional electric heating. The ZIF-8 obtained by microwave heating has larger surface area and micropore volume compared with the ZIF-8 synthesized with conventional electric heating. It can be confirmed that ZIF-8s show type-I adsorption isotherms, explaining the microporosity of the ZIF-8s. Based on FTIR and TGA results, it can be understood that the ZIF-8s have similar bonding and thermal characteristics irrespective of heating methods such as microwave and conventional heating.

• Journal of the Korean Geosynthetics Society
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• v.1 no.1
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• pp.13-21
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• 2002

Geotextile tubes hydraulically or mechanically filled with dredged materials have been applied in hydraulic and coastal engineering in recent years(detached breakwater, groins and jetty). The geotextile tubes are made of sewn geosynthetics sheets. If the sandy soil is use to fill material, these inlets should be spaced closely to assure uniform filling of the tubes because sandy soil and geosynthetic is very pervious. However, the clayey soil or contaminated slurry is used, the inlets can be located relatively long distance. The fine clayey particles tend to rapidly blind the fabric slowing down water escape through the geotextile. This paper presents a field test result of a geotextile tube in the land reclamation project for the Songdo New City construction site. The dredged silty clay was dredged by the dredging ship and hydraulically pumped into the geotextile tube. The height of geotextile tube was measured at every filling stage and also measured width and diameter of geotextile tube with the elapsed time. Based on the test results, if the clayey filling material is used, the pumping step must be divided 3~4 stages for drainage and sediment. After complete drainage, the height of the geotextile tube reduces by approximately 50%.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.05a
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• pp.140-148
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• 2002

컴퓨터를 통해 편리한 생활을 추구해온 인간들은 전자상거래 분야에서도 이러한 욕구를 충족시키기 위해 자동협상이라는 기능을 요구하게 되었다. 지능형 에이전트를 이용한 자동협상은 인간의 거래협상 업무의 부담을 많은 부분을 덜어주고 있어 자동협상 에이전트에 관한 연구들이 활성화되고 있다 소비자간 전자상거래에서는 다수의 자동협상 에이전트 연구들이 경매시장에서의 자동협상에 초점을 맞추고 있는데 반해, 가격 이외의 여러 거래속성을 갖는 상품에 대한 제안기반 협상시장에서의 자동협상 에이전트에 관한 연구들이 최근에 활발히 이루어지고 있다. 본 연구에서는 소비자간 전자상거래에서 거래속성의 변화에 따라 개인의 효용가치의 차이를 이용한 다속성 상품의 제안기반 협상시장이 가져야할 특성에 대해 연구하고, 이를 기반으로 자동 거래협상을 수행에 필요한 거래속성 변화에 따른 소비자 개인의 선호체계를 표현하기 위한 방법을 개발하였다. 그리고 이러한 자동 거래협상을 공정하게 수행하기 위해 협상시장이 가져야할 특징과 프로토콜을 제안하고 시장운영 에이전트 시스템의 구조를 설계하였다. 마지막으로 이러한 분산형 시장구조를 갖는 제안기반의 협상시장에 참여하는 사용자 에이전트 시스템이 최적의 거래상대와 최적의 거래안을 찾기 위한 탐색방법을 구체적으로 개발하였다. 본 연구의 결과를 통하여 소비자간 전자상거래에서 구매자 뿐만 아니라 판매자도 협상결과에 따른 거래로 얻어지는 자신의 효용을 극대화할 수 있는 공정한 협상시장을 운영할 수 있을 뿐만 아니라 사용자들도 손쉽게 자신의 협상 선호체계를 쉽게 표현하고, 표현된 선호체계를 반영한 자동 거래협상을 수행할 수 있을 것 이다. 기존의 UN/EDIFACT표준을 사용하고 있는 EDI환경과 기존 VAN 방식의 EDI 중계 시스템과 연동되며, 향후 관세청의 XML/EDI 표준 시행을 미리 대비하는 선도연구로서 자리매김이 된다. 본 연구에서는 개발된 XML/EDI 통관시스템은 향후, 서비스의 최대 걸림돌이 되어왔던 값비싼 EDI 사용료의 부담에서 벗어날 수 있게 할 것이며, 저렴한 EDI구축/운영 비용으로 전자문서교환의 활성화와 XML이 인터넷 기반의 문서유통 표준으로 자리매김할 수 있는 중요한 계기가 될 것이다.재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.ting LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is the number of recycled data buffer without