• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.373-384
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• 2011

The objective of this was to determine how the seasonal intensive rainfall influenced the water quality, and to analyze the long-term temporal trend of water chemistry and spatial heterogeneity in the upstream watershed of Southern Han River using water quality dataset from 1997 to 2007. The largest seasonal variability in most parameters occurred during the two month July and August and there were closely associated with a large spate of summer monsoon rain. Total phosphorus (TP), chemical oxygen demand (COD), and suspended solids (SS) were greater during summer than any other seasons, and had a direct correlation with precipitation (r>0.4, p<0.01, n-120). In addition, dissolved oxygen (DO) had and inverse function with precipitation (r=-0.542, p<0.01). Overall, the data of total phosphorus (TP) and suspended solids (SS) showed that water quality was worst in Site I1, compared to the others. This was due to continuous effluents from the highlands' fields and cattle farms within the upstream area of Doam lake (Song stream). Based on the overall dataset, an efficient water quality management is required in the highlands and farms areas for better water quality with precipitation (r.0.4, p<0.01, n=120).

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.95-105
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• 2003

Because the basic assumptions of deterministic user equilibrium assignment that all network users have perfect information of network condition and determine their routes without errors are known to be unrealistic, several stochastic assignment models have been proposed to relax this assumption. However. it is not easy to solve such stochastic assignment models due to the probability distribution they assume. Also. in order to avoid all path enumeration they restrict the number of feasible path set, thereby they can not preciously explain the travel behavior when the travel cost is varied in a network loading step. Another problem of the stochastic assignment models is stemmed from that they use heuristic approach in attaining optimal moving size, due to the difficulty for evaluation of their objective function. This paper presents a logit-based stochastic assignment model and its solution algorithm to cope with the problems above. We also provide a stochastic user equilibrium condition of the model. The model is based on path where all feasible paths are enumerated in advance. This kind of method needs a more computing demand for running the model compared to the link-based one. However, there are same advantages. It could describe the travel behavior more exactly, and too much computing time does not require than we expect, because we calculate the path set only one time in initial step Two numerical examples are also given in order to assess the model and to compare it with other methods.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.72-72
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• 2012

Lithium rechargeable batteries have been widely used as key power sources for portable devices for the last couple of decades. Their high energy density and power have allowed the proliferation of ever more complex portable devices such as cellular phones, laptops and PDA's. For larger scale applications, such as batteries in plug-in hybrid electric vehicles (PHEV) or power tools, higher standards of the battery, especially in term of the rate (power) capability and energy density, are required. In PHEV, the materials in the rechargeable battery must be able to charge and discharge (power capability) with sufficient speed to take advantage of regenerative braking and give the desirable power to accelerate the car. The driving mileage of the electric car is simply a function of the energy density of the batteries. Since the successful launch of recent Ni-MH (Nickel Metal Hydride)-based HEVs (Hybrid Electric Vehicles) in the market, there has been intense demand for the high power-capable Li battery with higher energy density and reduced cost to make HEV vehicles more efficient and reduce emissions. However, current Li rechargeable battery technology has to improve significantly to meet the requirements for HEV applications not to mention PHEV. In an effort to design and develop an advanced electrode material with high power and energy for Li rechargeable batteries, we approached to this in two different length scales - Atomic and Nano engineering of materials. In the atomic design of electrode materials, we have combined theoretical investigation using ab initio calculations with experimental realization. Based on fundamental understanding on Li diffusion, polaronic conduction, operating potential, electronic structure and atomic bonding nature of electrode materials by theoretical calculations, we could identify and define the problems of existing electrode materials, suggest possible strategy and experimentally improve the electrochemical property. This approach often leads to a design of completely new compounds with new crystal structures. In this seminar, I will talk about two examples of electrode material study under this approach; $LiNi_{0.5}Mn_{0.5}O_2$ based layered materials and olivine based multi-component systems. In the other scale of approach; nano engineering; the morphology of electrode materials are controlled in nano scales to explore new electrochemical properties arising from the limited length scales and nano scale electrode architecture. Power, energy and cycle stability are demonstrated to be sensitively affected by electrode architecture in nano scales. This part of story will be only given summarized in the talk.

• Journal of KIISE:Information Networking
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• v.33 no.4
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• pp.333-342
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• 2006

The cdma2000 lxEV - DO mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand from multimedia data services. The servicing of video streams over a BCMCS network must, however, face a challenge from the unreliable and error-prone nature of the radio channel. The BCMCS network uses Reed-Solomon coding integrated with the MAC protocol for error recovery. We analyze this coding technique and show that it is not effective in the case of slowly moving mobiles. To improve the playback quality of an MPEG-4 FGS video stream, we propose the Hybrid error recovery scheme, which combines Reed-Solomon with ARQ, using slots which are saved by reducing the Reed-Solomon coding overhead. The target packets to be retransmitted are prioritized by a utility function to reduce the packet error rate in the application layer within a fixed retransmission budget. This is achieved by considering of the map of the error control block at each mobile node. The proposed Hybrid error recovery scheme also uses the characteristics of MPEG-4 FGS (fine granularity scalability) to improve the video quality even when conditions are adverse: slow-moving nodes and a high error rate in the physical channel.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.150-155
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• 2015

Recently, LNG receiving terminals have been widely constructed and expanded for an increase in LNG demand. Selection of the storage tank for send-out and estimation of send-out flow rate have significant influence to process operation and economics. In this study, a send-out flow rate of each storage tank is optimized in order to minimize the total BOG generation rate. Considering a size and characteristic of each storage tanks, BOG flow rates are estimated using a dynamic simulation with varying liquid levels in the tanks. The regression model is developed fitting BOG flow rates and tank liquid levels, which are boil off rate model to predict BOG flow rates with particular level data. The objective function and constraints including required total send-out flow rate and level limit in the tanks are formulated to optimize a send-out flow rate of each tank. This method for optimization of send-out operation is applied to the Incheon LNG receiving terminal considering two scenarios for various liquid levels and maximum and minimum required send-out flow rates. For maximum required send-out flow rate, this method achieves BOG reduction of 9% comparing with assumed conventional operation.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.501-519
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• 1996

There are two kinds of commercially available ginseng root, red ginseng and white ginseng processed from fresh ginseng root Those ginsengs are primary product from fresh ginseng root and have the characteristic of keeping their original root shape Processed ginseng products are made from either red ginseng or white ginseng by way of complicated process of pulverization. Extraction. Condensation, fettering, sterilization, etc. Among them there are extracts. extract powder, powder, capsules tablets, Candy, drinks, nectar, jelly, gums. chicken soup. tonic. etc. to meet the demand for consumer's pretheronce . The 200 kinds of processed secondary products are approximately produced in the form of 20 kinds of ginseng products by about 60 domestic companies. In spite of about 213.000 million won of domestic market in 1993. it seems like that the ginseng market of the future has not a good prospects The total market sale of white ginseng in Korea has been continuously decreased since 1991 And 963 tons of white ginseng was consumed in domestic market in 1993 The domestic market sales of white ginseng in origina1 root shave. was 90, 000 million won in 1993 and market price of the fine root used as a source of processed products has not been changed in these ten years. The total market sale of red ginseng and its processed products was 58, 000 million won in 1993 9.800 mi11ion won of red ginseng in original root shape and 48.000mi11ion of processed red ginseng product. Ginseng products such as extracts, drinks, teas and tonics etc atre mostly exported to south-east Asia. And the total exports of ginseng pi.oducts (extracts, drinks teas) decreased to 54 million dollars in 1994, compared with 85 million dollars in 1992. Despite of extensive knowledge about ginseng little is still known about the development of new processed ginseng pl.oducts because of "Know-How". Some papars have presented the effects of extracting method(amounts of solvent. time. temperature, equipment. etc.) on the quality and yields of ginseng extr acts. Also. some researchers have carried out a few studies on the poriflcation of the extracts and the amounts of precipitation in the drink at variotas pH during the storage for preventinly drink from precipitation. A fell studies on the preservation of Korean ginseng powder. tea. Extract powder by irradiation and ozone treatment have been reported by some researcher for the improvement hygienic quality of ginseng products There are also some reports about the effects of ginseng components on the acid production by lactic acid bacteria or acetic acid bacteria. and alcohol production by yeast for the development of new ginseng products processed by fermentation. To make ginseng more able to contribute to the health of mankind in the future. consistent and considerable efforts should be focussed on improving the taste of ginseng and developing various new product as a health food or a function food.tion food.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.6
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• pp.54-63
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• 1999

Considering that rural village had evolved through a long-sustained effort of harmnization with nature, there should be the wisdom not only to reflect the level of rural resident's housing demand, but also to conserve the traditional characteristics of high-valuation in the modern rural housing. In Korea , standard design proposals of rural houses had been made public three times ; in 1972 , 1984 and 1995. so , firstly, this study analysed the inner-space layouts of design proposals mentioned above, from which changes and problems in the past housing design were derived. And also, through, the positive acceptance of residents' opinion living inthe houses built by standard design proposals in 1970 ~1980's, improved design principles and an alternative model were proposed , finally. The inner-space structed of standard design proposals in 1970s was originated from small-scaled and low-priced one, basically under the " open system". In 1980s, the basic design principle changed to the 'closed system' in which the living room being the focus of indoor family life, and , in 1990s, progressively, therural housing developed to the high qualified type by the spatial enlargement and with increased equipements. However, this structural change of rural house brought about the problem of functional separatioon between farming and daily living activities. In details, limited spaces of multipurpose spaces and sanitary facility would be mentioned as problems for improvement. conclusively in this study, newoly arranged "open system" was recommended , as a basic design principle for theinner space structure formation of rural house, which easily links the constituent inner-house spaces to outer one. Based on this principle, the detailed design criterial was proposed as follows ; 1. The living room be directly linked to the front-yard and centrally placed, the addtional space of which could be secured for the special family events by the flexibleuse of its adjacent room or by the housing of male quarters(separated from main building quarter). 2. The kitchen also be directly linked to side-yard and to livng room , for the convenience of farming activities and the shortening of path flow housewife. 3. The expanded toilet-and-bathroom be placed in the directly connected left-hand side to the living room and also be allowed access through multipurpose spaces to out door. 4. The multipurpose spaces be directly connected to the kitchen and the toilet and-bathroom , of which function would be for undressing of working clothes, quickwashing and ordinary working.nd ordinary working.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.76-91
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• 2017

The Area of a domestic railway station is designed based on the 4-step traffic demand forecasting model with the average daily passenger count as one of its parameter. However, nowadays, due to increasing rate of railway station's function, the non-passengers are increasing. In order to consider those non-passengers who aren't using trains, assumed volume are added to the average daily passenger count of station to estimate the area, but the criteria being applied has no concrete basis. Therefore, this study aimed to recalculate the increasing non-passenger rate based on actual survey data of station users in any type of railway station to obtain the optimum area. Subsequently, the the design area was performed through pedestrian simulation. According to the result of the simulation, it was found that the total space of the exciting railway stations can be reduced up to 45% and will still satisfy the level of service(LOS) requirement.

• Journal of Arbitration Studies
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• v.18 no.1
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• pp.121-145
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• 2008

Northeast Asia is increasingly making a transition to distinctive and crucial region in the 21st Century and growing into one of world's top three economic spheres along with the EU and NAFTA. In 2003, Korean government announced the Northeast Asian economic hub country plan as an important agenda. As a means of coping with the changing global environment, Korean government designated Incheon in 2003 as the country's first Free Economic Zone ahead of Busan and Gwangyang Bay in the south of the country because Incheon has a geographical advantage linking North America and Europe with Incheon International Airport and Incheon Seaport. The purpose of this paper is to make research on establishment and operation of an arbitral body entitled ${\ulcorner}International Arbitration Center{\lrcorner}$ (IAC) within Incheon Free Economic Zone(IFEZ). For the purpose of this, the writer in this paper, reviewed the necessity of the IAC's establishment and its legal basis as well as the role and function of the Center. Also, the writer presented plans for how to operate the IAC and how to cooperate with the key arbitral organizations of foreign countries for the settlement promotion of commercial disputes including trade and investment. With development of the IFEZ, world-renowned enterprises will invest in the Incheon economic bloc and conduct economic activities, business operation, marketing, logistics, financing, etc. In this connection, diverse types of commercial disputes are expected to occur between foreign companies entering the IFEZ and Korean firms. In this connection, the Korean Commercial Arbitration Board(KCAB) has been operating its liaison office in the IFEZ since 2004. However, in view of the increasing arbitration demand, the IAC should be set up in the IFEZ in the near future by the positive support of the government in the respect of both administration and finance because the free economic zone-related law provides for the installation of arbitration organization. For the success of the IAC, the Center will have to provide not only good quality of arbitral services that can satisfy arbitration parties but also need to conduct researches and make efforts so that arbitration can be utilized well in the IFEZ. If the IFEZ can provide advantageous business environments to those multinational enterprises intending to the Incheon economic bloc, the IAC will also contribute to the settlement of commercial disputes arising from the Gaeseong Industrial Complex in North Korea in view of the geographical advantage and logistic benefit of the IFEZ. Finally, this paper also suggests a new model for a joint dispute resolution system by the initiative of Korean government and Korean arbitral organizations for the settlement of commercial disputes within Northeast Asia, for which the CAMCA(Commercial Arbitration and Mediation Center for the Americas) of NAFTA can be a good example.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.67-76
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• 2004

This study presents the evaluation of CSM(Capacity Spectrum Method, ATC-40) in developing fragility curves for a sample concrete bridge. The CSM is originally developed as one of the simplified procedures for building structures, while this study adopts the CSM to develop fragility curves of bridge structures. Four(4) different approaches are demonstrated and the fragility curves developed are compared those by the nonlinear time history analysis. Fragility curves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. The sixty(60) ground acceleration time histories for the Los Angeles area developed for the Federal Emergency Management Agency (FEMA) SAC(SEAOC-ATC-CUREe) steel project are used for the bridge analysis. The comparison of fragility curves by the CSM with those by the time history analysis indicates that the agreement is excellent for one of the methods investigated in this study. In this respect. it is recommended that the demand spectrum might be improved according to the guidelines suggested in this study. However, this observation might not always apply, depending on the details of specific bridge characteristic