• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.227-232
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• 2009

Land application of animal manure, such as pig slurry(PS), has been considered as valuable organic source to supply necessary nutrients for crop growth. On the other hand, little information is available on the effect of consecutive application of PS on agricultural soils. This study was conducted to evaluate the influence on change in soil chemical properties and yield of Chinese cabbage in soils amended with slurry composting and bio-filtration pig slurry (SCB) for four consecutive crop cultivations (2007-2008). Among total application rates required, a basal fertilizer (35%) was applied with SCB or chemical fertilizer (CF). The CF was applied as a side dressing was applied in all treatments. There was no significant effect of SCB and CF on Chinese cabbage yield during four cropping seasons. In addition, soluble sugar, vitamin C contents and yields of Chinese cabbage between SCB and CF did not show statistically significant difference. During the experiment, soil chemical properties between SCB and CF treatment showed similar pattern, however, the contents of exchangeable sodium (Na) in soil has been increased (P<0.05) since the second cropping season because of higher Na contents in SCB. Therefore, the use of SCB as a substitute of CF is available for growth and yield of chinese cabbage while its long-term application might leads to an accumulation of Na in soil.

• Korean Journal of Organic Agriculture
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• v.11 no.2
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• pp.103-113
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• 2003

The chemical properties of oak tree wood vinegar and the effect of wood vinegar on the tomato seedling were investigated to apply wood vinegar efficiently to the organic - and natural farming system. On the basis of the results from chemical properties of the oak tree wood vinegar, mineral nutrient contents of wood vinegar was low. Therefore, wood vinegar could not be a suitable nutrient source for the plant growth at 500∼1000 times dilution level. which commonly used in the farming, if only wood vinegar is supplied for the nutrient source for the plant growth. The application of wood vinegar increased root growth up the 500 times dilution level while decreased shoot growth. Furthermore. the anion concentrations such as nitrate and phosphate of the plant were decreased by the application of wood vinegar while cation concentrations such as K. Ca. and Mg were increased. Phenolic compounds of wood vinegar such as chlorogenic acid and ferulic acid enhanced the root growth. Interestingly the application of ferulic acid increased both root and shoot growth at the level of 10$^{-4}$ M concentration. It indicated that the effect of wood vinegar on the production of healthy plant seedling may be due to the beneficial root growth by phenolic compounds such as chlorogenic acid and/or ferulic acid of the wood vinegar. However. the effect of the wood vinegar on the plant growth could be influenced by synergism or antagonism of different phenolic compounds in wood vinegar used. In addition. drench in the soil of wood vinegar may be more beneficial compared to foliar application for the improvement of root activity and plant growth.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.813-832
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• 2009

As accessibility to health-care service in less populated rural areas is geographically limited and demand for public health-care by the aging is increasing, a new approach for health-care service such as a home care service is becoming more popular. For a home care service, health-care personnels directly visit to location of health-care clients. Such changes in provision of health services require developing innovative and scientific approaches for efficient allocation of health resources and managing services by public health-care organizations. The purpose of this study is to formulate a location model for visiting health-care districting for the rural elderly and to develop an Automated Zoning Procedure (AZP) to solve this model. Mobility, workload balance and contiguity criteria are considered in the model. Three different objective functions are evaluated; 1) minimizing the sum of network distance between the unit areas in a district, 2) maximizing spatial interaction between the unit areas in a district, and 3) minimizing tour distance that visits each unit area exactly once in a district. The AZP for solving the model is developed and applied to a rural area. The application results demonstrate that the AZP can generate different districting systems for each objective functions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.51-58
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• 2018

This study was a basic research for actual production of recycled aggregate concrete, and experiments were carried out on the change of water cement ratio and physical properties of recycled aggregate concrete with fixed slump. Results were as follows. Concrete using recycled aggregate were required increased water to maintain the target slump, and the recycled fine aggregate are necessary more increased water more than the recycled coarse aggregate. The replacement ratio of recycled fine aggregate be less than 60%, would be possible to obtain the air content volume that did not deviate from the concrete quality specification. The compressive strength of concrete using recycled aggregate decreased with increasing the replacement of recycled aggregate, and compressive strength decreased by 25% when 100% recycled fine aggregate were replaced. As a result of analyzing the correlation of compressive strength according to the mixing factors of concrete, it was found that replacement of recycled fine aggregate> water cement ratio> air content volume were influenced in order.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.61-61
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• 2003

자바리, Epinephelus bruneus는 제주에서 다금바리로 불리우고, 제주도 남부 연안에서 주로 어획되며, 식용어로서 기호도가 높은 어종이다. 자바리의 자원량 격감과 가격상승으로 양식 산업화를 위한 종묘생산에 기술개발이 요구되는 실정이다. 이 실험에 이용된 자바리 어미는 전장 81.5$\pm$3.5 cm, 체중 7,38$\pm$1.06 kg에서 인공 채란된 난과 정자를 인공 수정방법을 이용하여 얻었다. 알의 직경은 900.11$\pm$2.52 $\mu$m이었고, 유구경은 233.98$\pm$2.48 $\mu$m이었다. 수정란은 수온 $25^{\circ}C$에서 32시간 30분에 부화(50%)되었고, 부화율을 96.76$\pm$0,49%였다. 부화자어는 90일 동안 로티퍼, Artemia nauplii, 인공사료를 공급하였다. 부화 직후의 자어는 전장이 2.02$\pm$0.02 mm이였다. 부화 후 3일째(2,76$\pm$0.08 mm) 난황이 대부분 흡수되고, 입이 열렸다. 개구시 입의 크기는 219$\pm$10 $\mu$m 이었다. 부화 후 3일째 막지느러미 후부에 색소포 침적이 일어났다. 부화 후 11일째(4.12$\pm$0.09 mm) 등지느러미 제2극조와 배지느러미 극이 돌출하였다. 부화 후 17일째(6.10$\pm$0.14 mm) 자어에 있어서 꼬리지느러미, 등지느러미의 기조 부위가 발생하기 시작하였다. 부화 후 54일째(41.12$\pm$l.20 mm) 모든 지느러미의 기조는 대부분 분화되어 성어와 비슷한 체색과 체형을 갖는 치어로 발달하였다. 부화 후 78일째 치어는 전장 55.86$\pm$1.26 mm, 체중 3,64$\pm$0.25 g으로 성장하였다.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.75-84
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• 2014

In this paper, we constructed a sensor network environment where various sensors are used. Then, we evaluated the performance when this environment adopted existing clustering algorithms that are designed for only single type sensors network. In our experiments, we considered two different types of the networks. In the first, all nodes are equipped with identical sensors. In the second, all nodes are equipped with three different types of sensors. We measured performance variations of several clustering schemes in accordance with sensor data accuracy, sensor node resource depletion timing, amount of available energy, node isolation ratio, and network lifetime. According to our performance analysis, we proved that existing clustering algorithms are partially inefficient to maintain the various-sensor network. Consequently we suggest that a new algorithm is required to take aim at the various sensor network.

• Journal of Korea Game Society
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• v.6 no.2
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• pp.51-60
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• 2006

Smoothing is a transmission plan where variable rate video data is converted to a constant bit rate stream. Among them are CBA, MCBA, MVBA, PCRTT and others. But, in these algorithm, a transmission plan is made in according to stored frame sequence in these algorithms. In case that the number of bytes in frames in GOP differs greatly each other, this may cause unnecessary transmission rate changes and may require high transmission rates abruptly when frame's byte is large. In result, it is difficult to use efficient network resource. In this paper, we proposed a smoothing algorithm that find the optimal frame sequence in short time by using backtracking method and smoothing's structure for the proposed smoothing algorithm. This algorithm decides the sequence of frames which requires the lowest variance of frame's bytes in GOP and make a transmission plan. In order to show the performance, we compared with MVBA algorithm by various evaluation factors such as the number of rate changes, peak rate, rate variability.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.525-535
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• 1999

An optimal unit commitment model for efficient management of water and energy resources in a basin using combined mixed integer programming is developed. The combined mixed integer programming model is able to solve the inconsistency problem that may occur from mixed integer programming models. The technique which enables the use of conditional constraints and either-or constraints in the linear programming is also suggested. As a result of applying the combined mixed integer programming model to Lower Colorado River Basin in United States. the basin efficiency is decreased by 1.53% from the results of the mixed integer programming, while it is increased by 0.67% from the results of the historical operation. It is found that the decreased allowable error between power supplies and demands in the combined mixed integer programming causes the decreased basin efficiency.

• Journal of the Korea Computer Graphics Society
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• v.17 no.2
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• pp.17-26
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• 2011

This paper presents an interactive progressive image transmission method, which enables a remote user to interactively select and transmit preferred regions from an index image. Our enhanced quadtree decomposition using PSNR-based rules and new implicit quadtree coding provide better rate-distortion performance than previous quadtree coders as well as leading bit plane methods. An adaptive traversal of child nodes is introduced for better visual display of restored images. Depth-first traversal combined with breadth-first traversal of the quadtree to accomplish interactive transmission as presented, results in a method that provides competitive performance at a low level of computational complexity. Moreover, our decoding requires only simple arithmetic which is enabling our method to be used for real-time mobile applications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.713-720
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• 2012

Recently, holography has received much attention as the next generation visual technology. Hologram is obtained by the optical capturing, but in recent years it is mainly produced by the method using computer. This method is named by computer generated hologram (CGH). Since CGH requires huge computational amount, if it is implemented by S/W it can't work in real time. Therefore it should use FPGA or GPU for real time operation. If it is implemented in the type of H/W, it can't obtain the same quality as S/W due to the bit limitation of the internal system. In this paper, we analyze the bit width for minimizing the degradation of the hologram and reducing more hardware resources and propose guidelines for H/W implementation of CGH. To do this, we performs fixed-points simulations according to main internal variables and arithmetics, analyze the numerical and visual results, and present the optimal bit width according to application fields.