• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.481-486
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• 2001

To increase the production efficiency in dairy industry, proper artificial insemination is the most important operation. For the successful artificial insemination, accurate estrus detection is required. The Korean dairy farmers usually depended on visual observation for estrus detection of cows. Mounting behaviour is one of major inidications observed when cows are at an estrus. A mounting activity detection system for cows using radiotelemetry was developed. This system included a transmitter with a pressure switch, a receiver, a serial communication interface, a personal computer and a computer software. All components and a whole system were tested both in a laboratory and in a farm. The results of this study are as follows: 1. All components including transmitter, receiver and serial interface were operated according to the design specification. 2. A whole system tested with simulated mounting activity of 400 times showed 100% of success rate. 3. In the farm test for 4 days with three cows expecting estrus, one cows experiencing mounting activities showed correct response with this system. However two cows did not show mounting activities because of weak estrus and cold weather during the testing period.

• Journal of Biosystems Engineering
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• v.20 no.1
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• pp.13-21
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• 1995

This study was conducted to investigate the cutting mechanism of reciprocating knife of combine harvester. The cutting operation of reciprocating knife with the arrangement of the low-cutting and the double-cutting was demonstrated through cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of reciprocating knives were analyzed using the developed program. The results are summarized as follows (1) The low-cutting type reciprocating knife was represented similar cutting characteristics to the standard type, but the maximum stalk-deflection was decreased as 1/2 level of the standard type. And the first ledger plate should be designed shorter than the second ledger plate. (2) The bunching area and the maximum stalk-deflection for the double cutting knife almost were not changed since cutting velocity ratio of 0.6, but the secondary cut were occurred at ratio of 0.8 and increased rapidly over these ratio. (3) The double cutting knife was recommended for the high speed combine, because its bunching area and the maximum stalk-deflection were decreased as 1/2 level of the standard type. (4) In order to maintain the proper cutting mechanism characterized by the bunching area, the maximum stalk-deflection and the secondary cutting length etc., the adequate cutting velocity at forward speed of 0.5㎧ to 1.2㎧ was from 0.3㎧ to 0.96㎧ for the double cutting knives.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.8-18
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• 1984

To investigate the most important factors affecting the mobility of power tiller and to find the method which can be used for predicting the mobility of power tiller in soft paddy field, a series of field experiment was performed with two models of power tiller (8ps and 6ps diesel). From the results obtained throughout field experiment, the following conclusions were derived. 1. The wheel sinkage of power tiller during both traveling and field operations, which mainly influence the mobility, could be predicted from both plate ($50{\times}100mm$) sinkage and soil cone index (30-degree cone with 2 and $6cm^2$ base area). 2. Prediction of wheel sinkage from the rectangular plate sinkage was found to be more suitable compared with the cone index. 3. The upper limit of rectangular plate sinkage was found as 15 centimeter for operation of power tiller in muddy field which is equivalent of $1kg/cm^2$ of $2cm^2$ cone index value.

• Journal of Biosystems Engineering
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• v.25 no.4
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• pp.301-310
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• 2000

An autonomous tractor system was developed and its performance was evaluated. The system consisted of a tractor system of and a remote control station. The tractor and the remote control station communicated each other via wireless modems. The tractor had a DGPS(differential global positioning system), sensors, a controller and a modem. The DGPS collected position data and the tractor status was estimated. The information of tractor status and sensors was transferred to the remote control station. Then, the control station determined the control data such as steering angles using a fuzzy controller. The fuzzy controller used the information from the DGPS, sensors, and GIS(geographic information system) data. The control data were obtained by remote signal processing at the control station The control data for autonomous operation were transferred to the tractor controller. The performances of an autonomous tractor were evaluated for various speeds, different initial positions and different initial headings. About 1.3 seconds of time lag was occurred in transferring the tractor status data and the control data. Compensation the time lag, about 27cm deviation was observed at the speed of 0.5m/s and 37cm at the speed of 1m/s. Error caused mainly by the time lag and it would be reduced by developing a full-duplex radio module for controlling the remote tractor.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.1
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• pp.35-40
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• 2008

The environment of agriculture in Korea is changed very rapidly. Since the labours in fruit cultivation field are getting older, the resources and the aid materials for farming need to be multi functional and easy to use. Therefore, They have to use various kind of aid materials in field of fruit cultivation like as fruiting bag. The development of practical utilization way of embossing process for manufacturing of fruiting bag and wrapping paper of agricultural products was main purpose of this study. Embossing roll was designed in Ginyong Embo(Co.) for the embossing process of fruiting bag. The embossing treated fruiting bag was manufactured in Agro(Co.) at mill scale. The mechanical properties of embossing paper was investigated and operation efficiency of bagging was tested at field. The properties of embossed paper was satisfied for fruiting bags for cultivation of apple and pear.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.447-447
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• 2012

농업용저수지 둑높이기 사업은 기존 농업용저수지의 둑을 높여 저수량을 추가확보하여 갈수기에 본류 및 지류에 환경용수 공급을 하기 위하여 시행 중이다. 기존의 농업용저수지는 농업용수라고 하는 단일 목적 용수 공급을 위한 저수지로서 용수공급은 대상작물의 재배시기에 맞추어 이루어지고 있다. 둑높이기 대상 농업용저수지는 농업용수 및 환경용수 공급이라는 다중목적을 수행하여 한다. 따라서 기존의 농업용저수지 운영기준과는 차별되는 운영기준 설정이 필요하다. 이에 본 연구에서는 농업용 저수지의 농업용수 공급 능력을 유지하며, 하류하천에 유지유량을 공급할 수 있는 운영기준을 설정하였는데, 농업용 저수지의 규모에 따라서 운영기준을 제안하였다. 먼저 중소규모 저수지의 운영기준은 운영기준곡선의 개념을 활용하여 현저수량을 운영기준곡선에 대입하여 적정 방류가능량을 설정하였다. 구체적으로 저수지 유입량을 고려하여 연중 방류 가능한 기준방류량을 선정하고, 기준방류량의 연중 방류에 따른 최대, 최소 방류기준곡선과, 사업 전 저수량을 고려하여 방류제한 곡선을 설정하였다. 한편 대규모 저수지의 경우 기준방류량을 설정하기 위하여 과거 30년 이상의 저수량 모의를 통하여 비관개시 시점의 각 초기저수량에 따라 관개기 시점의 목표 저수량을 만족할 수 있는 초기저수량별 기준방류를 설정하고 이를 바탕으로 운영 기준을 설정하였다. 설정된 운영기준을 적용하여 일별 저수량을 모의하고, 운영기준 적용에 따른 환경용수 공급 능력 및 이수안전도의 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4724-4747
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• 2016

To efficiently reduce on-grid energy consumption, the admission control algorithm in the hybrid energy powered cellular network (HybE-Net) with base stations (BSs) powered by on-grid energy and solar energy is studied. In HybE-Net, the fluctuation of solar energy harvesting and energy consumption may result in the imbalance of solar energy utilization among BSs, i.e., some BSs may be surplus in solar energy, while others may maintain operation with on-grid energy supply. Obviously, it makes solar energy not completely useable, and on-grid energy cannot be reduced at capacity. Thus, how to control user admission to improve solar energy utilization and to reduce on-grid energy consumption is a great challenge. Motivated by this, we first model the energy flow behavior by using stochastic queue model, and dynamic energy characteristics are analyzed mathematically. Then, fuzzy logic based admission control algorithm is proposed, which comprehensively considers admission judgment parameters, e.g., transmission rate, bandwidth, energy state of BSs. Moreover, the index of solar energy utilization balancing is proposed to improve the balance of energy utilization among different BSs in the proposed algorithm. Finally, simulation results demonstrate that the proposed algorithm performs excellently in improving solar energy utilization and reducing on-grid energy consumption of the HybE-Net.

• Journal of Information Management
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• v.23 no.2
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• pp.14-39
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• 1992

The effectiveness of the library operation with the least volume is to bring the same amount of utility as the library operating with the largest volume. The major objectives of this study are to evaluate the library collection of Library and Information Division, Korea Rural Economic Institute, the sample library, by the fields and areas of research, and to prepare an alternative for future library collection of KREI. In order to accomplish these objectives, use studies, relative use method, list-checking, and questionaries were used for the analysis.

• Korean Journal of Community Nutrition
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• v.23 no.6
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• pp.506-515
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• 2018

Objectives: We investigated the operation needs of school meal support centers (SMSC) in Chungnam-do based on analysis of nutrition teachers' perception of them. Methods: The Chungnam government established the first SMSC in 2012. Thirteen SMSCs are currently being operated in Chungnam-do. To analyze the results quantitatively, we investigated nutrition teachers opinions regarding the necessity for SMSCs as a dependent variable and derived the independent variables based on the causal relationships with dependent variables using the ordered logit model. Those independent variables included region, school type, number of students, attitude regarding free meal policy, satisfaction with school meal policy, and preference for local food. Results: Briefly, teachers in the region in which the SMSC was located more strongly supported the SMSC. In addition, teachers in public schools with a smaller number of students believed that having a SMSC is more beneficial, and that other variables also affected the necessity for SMSCs. Moreover, nutrition teachers preferred local foods rather than organic foods because of the unstable supply of organic foods. Conclusions: Based on the results of this study, it was recommended that the local government implement the policy consistently. Moreover, it was recommended that the government operate the SMSC more efficiently, enhance the roles of the SMSC as the local organization responsible for student nutritional planing and expand the coverage of agricultural products.

• Korean Journal of Remote Sensing
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• v.35 no.1
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• pp.151-162
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• 2019

Surface temperature has been derived from the MODIS/ASTER airborne simulator (MASTER) mid-wave infrared single channel data using the MODerate resolution atmospheric TRANsmission (MODTRAN) radiative transfer model with input data including the University of Wisconsin (UW) emissivity, the National Centers for Environmental Prediction (NCEP) atmospheric profiles, and solar and line-of-sight geometry. We have selected the study area that covers some surface types such as water, sand, agricultural (vegetated) land, and clouds. Results of the current study show the reasonable geographical distribution of surface temperature over land and water similar to the pattern of the MASTER L2 surface temperature. The thorough quantitative validation of surface temperature retrieved from this study is somehow limited due to the lack of in-situ measurements. One point comparison at the Salton Sea buoy shows that the present estimate is 1.8 K higher than the field data. Further comparison with the MASTER L2 surface temperature over the study area reveals statistically good agreement with mean differences of 4.6 K between two estimates. We further analyze the surface temperature differences between two estimates and find primary factors to be emissivity and atmospheric correction.