• Journal of the Korean Statistical Society
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• v.5 no.2
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• pp.109-118
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• 1976

현행 일반적으로 쓰여지고 있는 물가지수 산식은 기준시점의 거래량(또는 거래금액)을 상품별 가중치(weight)로 삼는 가중총합방식(weighted aggregate formula, 또는 가중산술평균산식)으로서의 Laspeyres식이라 함은 주지하는 바와 같다. 그것이 상품별로 유통면의 중요성을 분명히 감안하여 있고, 비교시점의 가격변동만이 계산에 반영된다는 점에 있어서 물가지수로서의 실용성이 널리 인정되어 있는 산식이다. 그러나 Lasperyres식의 난점을 또한 많은 것이니 그 가운데 특히 가중치의 고정성과 관련하여 기준시점의 이동에 따른 전후 물가지수의 비연결성은 결정적 결함이라 할 수 있다. 여기에 이 식의 지수적 허구성이 흔히 논의되고, 이른바 Paasche check라 하여 수시로 조사한 거래량(또는 거래금액)에 의하여 물가지수의 가중치로 삼아서 전자를 검정하는 방법도 쓰여지는 형편이다. 필지는 일찌기(1973년) Laspeyres식의 상품별 가중치에 관한 객관적 평가법의 하나로서 산업(따라서 상품)의 연관분석적 수단에 의한 약간의 시안을 발표한 바 없지 않았다. 그것은 요약컨대 산업연관분석에 쓰이는 투입계수표를 중심삼아 한 상품가격이 다른 상품가격에 미치는 파급효과, 따라서 물가에 미치는 파급력을 계산하고, 나아가서 각 상품의 수요 및 공급함수를 도입하여 그들 계수를 추정함으로써 가중치의 객관화를 꾀해 본 것이 전고의 골자이다.

• Journal of Korean Society of Forest Science
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• v.37 no.1
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• pp.17-30
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• 1978

Press drying was used on italian poplar (Populus euamericana) to find the profitable means of drying. This study was designed to investigate the process of platen drying considering core temperature, drying time, current moisture content, drying rate, shrinkage and recovery, and green volume specific gravity, equilibrium moisture content and dimensional stability of press dried material and air dried material, The drying tests were conducted using 1.5 centimeter thick material at platen temperature of $175^{\circ}C$. The results were summarized as follows. 1. Core temperature was divided into three stages of drying characterized by period initial heating, plateau temperature and rising core temperature. Plateau temperature was 114 to $119^{\circ}C$. 2. The following predicting equations of drying time(y) in different core temperatures were developed for initial thickness($x_1$), initial moisture content ($x_2$) and final moisture content ($x_3$) 3. The predicting equaltion of current moisture content(u) was log u=4.658-0.060t as funtion of drying time(t) and that of drying rate(r) was log r=-2.797-0.049t. Current moisture content and drying rate of air drying were shown in figure 2. 4. The predicting equation of shrinkage in thickness direction(y) was log y=1.933+0.038t as function of drying time(t), and that of expansion in width direction was $y=-0.692+0.043t-0.001t^2$. 5. Thickness shrinkage was increased more than proportional at to pressure increase. Width shrinkage and thickness recovery was greatest at 35psi. 6. Green volume specific gravity of press dried material was 25% greater than that of air dried material. But equilibrium moisture content of press dried material was less 24% than that of air dried material. Antishrinkage efficiency of press dried material were obtained 27.7%.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.120-131
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• 2009

This study measured the centripetal force and effective scope of the population spread from urban center and subcenters in order to diagnose the urban spatial structure of the formation of a multicentric city structure in Busan. The study analyzed the variability of the determination coefficient value (R square) with a negative exponential function derived from the population density model by extending the circular region into 5-km units. The aim of this study was to measure changes in the effective scope of the population centripetal force of the urban center and subcenter in 5-year intervals from 1995 to 2005 using census data. The explanatory adequacy of the population density function was examined with the bias of the function to calculate the distance error between the real location of the urban center and the optimal location, according to the population density function. To summarize the results, the value for the area of Jungangdong showed a continuous reduction, whereas Seomyeon (Bujeondong) maintained explanatory adequacy without a large change. As a whole, Busan was in the process of continuous diversification, in spite of its reduced population. Therefore, it appears necessary to strengthen the function of the urban center and subcenter and to supply adequate dwelling zones close to downtown to form a more efficient urban spatial structure. The results of the present study will be utilized as basic data for the formulation of a political approach to the efficient reorganization of spatial structure by correlating concrete spatial information with the population variability of Busan's urban center and subcenter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.340-349
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• 1995

There are several problems in a fishing by the midwater pair trawl net which is used in Denmark; steeply decreasing of the net height with the towing speed increasing, the larger volume of the fishing gear in comparison with the size of the trawler, and catching of a float in a mesh, etc. To prevent steeply decreasing of the net height with the towing speed increasing and catching of a float in a mesh, it is sometimes more useful to use the kite instead of floats. This paper describes the hydrodynamic drag and the opening efficiency of the midwater pair trawl net and the midwater kite pair trawl net obtained by the model test in the circulation water channel. The results can be summarized as follows; 1. The hydrodynamic drag of the midwater kite pair trawl net is about 0.7 times smaller than that of the midwater pair trawl net. 2. The net height, mouth area and filtering volume of the midwater kite pair trawl net are smaller then those of the midwater pair trawl net when the towing speed is below 2.5knots, almost the same at 2.7knots, and are larger over 3.0knots. The net width of the midwater kite pair trawl net is same as that of the midwater pair trawl net. 3. The shapes of net mouth of both net are an oval steeply flatted with the towing speed increasing. The filtering volume of the midwater kite pair trawl net is larger then that of the midwater pair trawl net by 3% at 3.0knots, 11% at 4.0knots, and 16% at 5.0knots respectively.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.1-9
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• 1986

Periodical samplings were made in the fields, located Hwasong-Gun, Banwal-Myon, Doondai-Ri, for two years to study the major factors responsible to the population of the overwintered pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye. The population densities of the overwintered larvae reduced greatly at the time of pupation and the changing patterns seemed to be influenced by environmental conditions. The estimated 50% pupation day was about two weeks earlier for the 1980 generation compared with the 1979 generation, and much higher average and the daily maximum temperatures in 1981 affected on the development of the larvae. The relative emergence rates were 14.1% for 1979 and 14.9% for 1980 generation. The relative emergence rates(Y) were affected by the moisture contents of soil ($X_1$) and its variance $(X_2),\;Y=-68.41+4.3206X_1-0.6887X_2$. The relative emergence rates seemed to be decreased with the increased variance of the moisture contents of soil. Percents of needle gall were 49.63% for 1980 and 86.87% for 1981 generation.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.35-48
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• 2019

Domestic hydraulic drifters till now have been developed by benchmarking products from overseas leading companies. However, they do not have excellent impact performance as they are not suitable for characteristics (large flow rate and low pressure) of Korean hydraulic drill power pack, and therefore, research on the optimum design has not made much headway. This study performs multi-objective function optimization for hydraulic drifters whose capacity has been redesigned to deal with the large flow rate, and also with the help of this function, it aims to improve impact power and reduce supply and surge pressure. A summary of the research study is as follows: First, we set goals for improving impact power, supply pressure, and surge pressure, and then perform multi-objective function optimization on them. After that, we secure the reliability of the optimized analytical model by comparing the test results of the prototype built by the optimized design with the analysis results of the analytical model. This study used SimulationX, that is the hydraulic system analysis software, and EasyDesign, which is a multi-objective function optimization program. Through this research, we have achieved the results that satisfy the goal of developing high power drifters suitable for Korean type hydraulic drills.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.113-122
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• 1986

In order to promote mechanization of corn harvesting in Korea, this study was conducted to find out the effect of moisture content on compressive properties such as force, deformation, energy and modulus of stiffness to the bioyield and the rupture point for Korean corn kernel. In this study, the loading positions of corn were flat, edge, longitude and the moisture contents were about 13, 17, 21, 25% in wet basis. The compression test was carreied out with flat plate by use of dynamic straingage for three varieties of Korean corn under quasi-static force when the loading rate was 1.125mm/min. The results of this study are summarized as follows; 1. When the moisture content of corn ranged from 12.5 to 24.5 percent, at flat position, the bioyied force was in the range of 13.63-26.73 kg and the maximum compressive strength was in the range of 21.55-47.65kg. Their values were reached minimum at about 17% and maximum at about 21% moisture content. The bioyield force was in the range of 13.58-6.70kg at edge position and the maximum compressive strength which was 16.42 to 7.82kg at edge position was lower than that which was 18.55-9.05kg at longitudinal position. 2. Deformation of corn varied from 0.43 to 1.37 mm at bioyield point and from 0.70 to 2.66mm at rupture point between 12.5 to 24.5% moisture content. As the moisture content increased, deformation was increased. 3. The moduli of resilience and toughness of corn ranged from 2.60 to 8.57kg. mm and from 6.41 to 34.36kg. mm when the moisture content ranged from 12.5 to 24.5 percent, respectively. As the moisture content increased, the modulus of toughness was increased at edge position and decreased at longitudinal position. And their values were equal each other at 22-23% moisture content. 4. The modulus of stiffness was decreased with increase in the moisture content. Its values ranged from 32.07 to 5.86 kg/mm at edge position and from 42.12 to 18.68kg/mm at flat position, respectively. Also, the values of Suweon 19 were higher than those of Buyeo. 5. It was considered that the compressive properties of corn at flat position were more important on the design data for corn harvesting and processing machinery than those of edge or longitudinal position. Also, grinding energy would be minimized when a corn was processed between about 12.5 to 17% moisture content and corn damage would be reduced when a corn was handled between about 19 to 24% moisture content in wet basis.

• Electronics and Telecommunications Trends
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• v.20 no.1 s.91
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• pp.167-175
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• 2005

본 연구는 현재 도입예정에 있는 차세대 통신 및 방송서비스의 확산가능성에 대하여 잠재적 사용자1,000명을 대상으로 조사한 최근 조사자료를 중심으로 실증분석하였다. 잠재적 사용자의 선택 및 반응함수추정방법은 분석의 객관성과 효율성을 유지하기 위하여 모수적 추정과 반모수적 추정방법을 동시에 사용하여 분석하였다. 본 분석결과를 요약하면 다음과 같다. 먼저, 차세대 통신 및 방송서비스사용자들의 해당 서비스선택반응함수를 분석한 결과 서비스확산은 상당히 느리게 이루어 질 수 있다는 결과를 보여 주었다. 이러한 분석결과는 기존 초고속 및 이동통신서비스 확산에서와 같이 형태의 빠른 확산속도를 보일 것이라는 낙관적 전망견해에 상당한 문제점이 있음을 보여 준다. 둘째, 본 연구의 차세대통신 및 방송서비스확산의 부정적인 분석결과에도 불구하고, 차세대 통신서비스의 성공적 확산에 중요한 요인으로는 서비스제공요금을 낮추고, 젊은 사용자층에게 새로운 서비스의 유용성을 인식시킴으로써 최종서비스선택까지 유도케 할 수 있는 유인 메커니즘 도입전략 개발이 사업성공의 필요조건이 될 수있음을 보여 주었다. 마지막으로 우리나라 통신 및 방송산업환경은 상용화를 준비하는 사업자들이 차세대 통신 및 방송서비스의 성공적 도입을 위하여 시장구조분석 및 시장욕구의 질적 방향분석뿐만 아니라, 그 영향 정도를 수치화하고 계량화하는 시장분석자료를 바탕으로 시장도입 및 전개전략을 개발하는 과정이 절대적으로 필요한 단계가 되었음을 보여 준다. 본 연구결과의 시사점으로 차세대 통신 및 방송서비스의 산업고도화에 대한 면밀한 사전계량시장분석으로 시장전략형성 전환적사고가 해당 서비스제공사업자뿐만 아니라 서비스정책을 수행하는 정부당국자에게도 필요과정요소가 되고 있음을 보여 준다.

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.130-133
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• 2006

This study was conducted to select Codonopsis lanceolata seed's new pelleting particulate materials and adhesives. Different adhesives (Polyvinyl alcohol (PVA), Carboxymethyl cellulose (CMC), Polyvinyl pyrrolidone (PVP), Xanthan gum (XG), Arabic gum (AG)) and particulate materials (Illite, Diatomite, Pyrophyllite + Illite + Diatomite (PID), Pyrophyllite + Illite + Talc (PIT), Bentonite + Talc (BT)) were tested for seed pelleting. PID for Codonopsis lanceolata seed pelleting appeared to be the best particulate material. Among the pelleting adhesives, PVP was the best adhesive for seed pelleting, and the optimum concentration for germination of pelleting seed was 1 %. Germination rate of the pelleted seeds treated with PID particulate material and PVP adhesive was higher (86.8%) than those of raw seeds (85.5%). $T_{50}$ and MDG of pelleted Codonopsis lanceolata seed required five and eight days at soil moisture content of 50%, respectively.

• Water for future
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• v.18 no.2
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• pp.175-185
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• 1985

This paper discusses the posibility of synthesizing flood hudrographs by the stroage function model. Eight small watersheds from Han, Gum, Nakdong, Youngsan river system were selected for this purpose. The optimum constants are computed from the chi square criterion by the SDFP methods Based on these constants, equations for the storage constant and Lag time are derived from the kinematic wave theory and storage function theory. These relations are examined by using optimum constants of the storage function model and assumptive constant of the kinematic wave model. Main results are sumarized as follows. 1. Constants of the storage function model are closely related to those of the kinematic wave model. The formula obtained theoretically is difficult to use practically because of the unclaified definition of factors. 2. In order to estimate constants of the storage function model for the practical purpose, new equations are also proposed for mountaneous area. 3. The verification of proposed equation is made for several recorded floods for mountaeous areas.