• Journal of the korean Society of Automotive Engineers
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• v.11 no.5
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• pp.55-64
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• 1989

The effect of discharge have been investigated for condition of spark in a multiple spark ignition engine, as the spark duration, capacitive and inductive discharge energy were calculated for condition of spark by ignition wave and energy formula. The useful portion of spark discharge is divided into capacitance portion and inductance portion. It was found that capacitive discharge energy and spark duration were increased according to increasing number of spark, and inductive discharge energy was increased according to increasing spark interval. Therefore engine torque was increase and lean misfire limit was extended comparing with the standard ignition system. It found that spark energy was discharged within ignition delay period availability acted on the formation and growth of flame kernel, and total spark energy was increased according to increasing number of spark times, but discharged spark energy after ignition delay became unavailable energy. And the capacitive discharge energy has the dominant effect for stoichiomeric or not very rich air-fuel mixture but inductive discharge energy has the dominant effect for lean air-fuel mixture.

• Journal of the Korean Statistical Society
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• v.4 no.2
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• pp.127-138
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• 1975

There have been a number of studies and analysis designed to explain imports and exports disaggregated by commodities in many countries. These analyses, however, all concentrate on the trading patterns of industrial countries, and there has been very little of systematic analyses of the imports and exports by types of commodities for developing countries. There is, of course, an obvious reason for ignoring these countries, and that has to do with the availability, or rather paucity, of adequate data; it is widely known that the data on prices of disaggregated imports and exports are most difficult to obtain. The purpose of this paper is to study and analyze the behavior of the imports of Korea at disaggregated levels during the period 1965-1974. Data on imports at a disaggregated level have recently been made available in Korea for a seven-commodity breakdown. These seven categories cover some 90% of the total Korean imports.

• Journal of Plant Biology
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• v.22 no.3
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• pp.63-69
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• 1979

The plant growth and net production, the nitrogen uptake and recycling, the nitrogen mobility and allocation to each organ, and the nitrogen utility from the Italian rye grass field during the population development were analyzed in comparison with different clipping treatments. The maximum dry matter standing crop and nitrogen quantity of harvest increased significantly, however, the annual amounts of dry matter and nitrogen assimilation showed little variations with increasing clipping frequencies. Plants treated with frequent clippings allocated relatively more nitrogen to leaves and less to roots during the experimental period. The amount of recycling of nitrogen decreased considerably due to frequent clippings. The annual averages of nitrogen utility indices changed in inverse relation to the nitrogen availability; such as 63, 58, 44 and 35 for C, A, M and J plots, respectively.

• International Commerce and Information Review
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• v.2 no.1
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• pp.3-24
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• 2009

This study extends the previous research into the effects of knowledge spillovers on innovation and regional exports growth by more clearly distinguishing, both theoretically and empirically, two different types of knowledge spillovers, namely product and market knowledge spillovers. More importantly, this research provides insights on their role of knowledge spillovers in shaping regional innovative activities and, eventually, regional export growths. Furthermore, this research makes an important contribution to the understudied market knowledge spillovers by developing two variables that could be used to assess the flow of market knowledge spillovers at the regional level: localization economies and export consulting advice. Using secondary data on eight 2-digit manufacturing industries in ten New Zealand regions over a seven year period, this research found that regional competition, localization economies and the availability of export consulting advice have positively and significantly impact on the regional export growth in New Zealand.

• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.30-34
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• 1996

This study was performed to examine the availability of using medaka (Oryzias latipes) in teratological test. Medaka embryos were collected within 2 hours post-fertilization and cultured in petri dishes containing buffered saline until hatching. The embryos were treated with 0.56 mg/l chlorpyrifos-methyl and 10 mM methyl methanesulfonate at 20 stages (about 35 hours post-fertilization). Eleven developmental features were selected and observed from 33 stages (about 9 days post-fertilization). Scoring system was developed and applicated for the measurement of potential teratological effects by the test compound. Chlorpyrifos-methyl did not induce teratological effect in medaka embryos. However, we found teratological test using medaka embryo reduced the cost, labors, period and space of experiment significantly compared with teratological study using rodents. Above findings strongly suggest that medaka embryo can be used as a lab animal model for teratogenicity test instead of rodents.

• Earthquakes and Structures
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• v.7 no.6
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• pp.1241-1258
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• 2014

This is paper presents the results of an analytical study aimed at evaluating the effect of narrow-banded mainshock/aftershock seismic sequences on the response of structures built on very soft soil sites. Due to the scarce availability of recorded seismic sequences in accelerographic stations located in the lake-bed of Mexico City, artificial narrow-banded sequences were employed. In the first part of this study, a parametric investigation was carried out to identify the mainshock/aftershock ground motion features that have detrimental effects in the seismic performance of equivalent single-degree-of-freedom systems representative of framed-buildings that house standard and essential facilities. In the second part of this work, the seismic response of two (8- and 18-story) steel-moment resisting frames that house essential facilities is examined. It is concluded that buildings with fundamental periods of vibration longer than the dominant period of the mainshock can experience a significant increment in their inter-story drift demands due to the occurrence of an aftershock.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.293-299
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• 1995

A methodology is applied to identify tile learning trend related to the safety and availability of U.S. commercial nuclear power plants. The application is intended to aid in reducing likelihood of human errors. To assure that tile methodology ran be easily adapted to various types of classification schemes of operation data, a data bank classified by the Transient Analysis Classification and Evaluation(TRACE) scheme is selected for the methodology. The significance criteria for human-initiated events affecting tile systems and for events caused by human deficiencies were used. Clustering analysis was used to identify the learning trend in multi-dimensional histograms. A computer rode is developed based on tile K-Means algorithm and applied to find the learning period in which error rates are monotonously decreasing with plant age.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.331-343
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• 2015

We propose a distributed medium access control protocol for cognitive radio networks to opportunistically utilize multiple channels. Under the proposed protocol, cognitive radio nodes forecast and rank channel availability observing primary users' activities on the channels for a period of time by time series analyzing using smoothing models for seasonal data by Winters' method. The proposed approach protects primary users, mitigates channel access delay, and increases network performance. We analyze the optimal time to sense channels to avoid conflict with the primary users. We simulate and compare the proposed protocol with the existing protocol. The results show that the proposed approach utilizes channels more efficiently.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.386-389
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• 2002

It may be necessary to apply a daily fever to operate the municipal solid waste landfill. The daily cover helps to control nuisance factors such as the escape of odors, dusts and airborne emissions, and can control the population of disease vectors. Also it may be reduce the infiltration of rain, decreasing the generation of leachate and the potential for surface water and groundwater contamination. Because of its usual availability and traditional usage as the municipal solid waste landfill, soil remains as the most common daily cover material. However, soil tends to reduce the volume of dumping waste c;3pacity in the landfill, it also reduces a period of using in the landfill. Therefore, it is necessary to research about Alternative Daily Cover Materials (ADCMs) because of the limitation of landfill sites. Recently, The types of ADCMs are classified into geosynthetics, forms, spray-ons, indigenous materials. In this study, the authors have tested the spray type of Alternative Daily Cover(ADC) using by flyash, alum with cement. The development. of ADCMs will be highly effective in terms of prolongation using landfill.

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.88-95
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• 2009

Most of subway stations are located underground and the number of passengers is far more than that of designed value, therefore the risk of accident is growing bigger and serious damage is expected in case of disaster. In Korea the period of evacuation study is short and numerical and experimental data of evacuation phenomena in subway station is rare. Many egress evaluation depend on foreign commercial S/Ws which are not yet proven its availability in special case such as subway station. In this paper outflow coefficients which are essential in egress evaluation are calculated at train door, stairway and turnstile at 3 most crowed subway stations. This numerical data can be used in prediction of egress evaluation and the result of other prediction methods can be verified with these experimental data.