• Molecules and Cells
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• 제23권1호
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• pp.72-79
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• 2007

Demand for low-input sustainable crop cultivation is increasing to meet the need for environment-friendly agriculture. Consequently, developing genotypes with high nutrient use efficiency is one of the major objectives of crop breeding programs. This study was conducted to identify QTLs for traits associated with physiological nitrogen use efficiency (PNUE). A recombinant inbred population (DT-RILs) between Dasanbyeo (a tongil type rice, derived from an indica ${\times}$ japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) consisting of 166 $F_8$ lines was developed and used for mapping. A frame map of 1,409 cM containing 113 SSR and 103 STS markers with an average interval of 6.5 cM between adjacent marker loci was constructed using the DT-RILs. The RILs were cultivated in ordinary-N ($N-P_2O_5-K_2O=100-80-80kg/ha$) and low-N ($N-P_2O_5-K_2O=50-80-80kg/ha$) (100 kg/ha) conditions. PNUE was positively correlated with the harvest index and grain yield in both conditions. Twenty single QTLs (S-QTLs) and 58 pairs of epistatic loci (E-QTLs) were identified for the nitrogen concentration of grain, nitrogen concentration of straw, nitrogen content of shoot, harvest index, grain yield, straw yield and PNUE in both conditions. The phenotypic variance explained by these S-QTLs and E-QTLs ranged from 11.1 to 44.3% and from 16.0% to 63.6%, respectively. The total phenotypic variance explained by all the QTLs for each trait ranged from 35.8% to 71.3%, showing that the expression of PNUE and related characters depends signify- cantly upon genetic factors. Both S-QTLs and E-QTLs may be useful for marker-assisted selection (MAS) to develop higher PNUE genotypes.

• Current Research on Agriculture and Life Sciences
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• 제27권
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• pp.1-6
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• 2009

우리나라에서 감은 재배면적으로 볼 때 사과 다음으로 넓은 면적을 차지하고 있다. 그러나 감 재배 포장의 70%가 경사지에 있어서 수확작업의 효율성이 떨어진다. 기존의 감 수확기구는 구조상의 문제로 인해 탈과가 용이하지 않고 또한 수확기구의 중량이 무거워 농민들이 사용하기에 적절하지 않아 작업능률이 저하되고 있다. 본 연구는 이와 같은 문제점의 해결을 위해 감과실의 과실-과경계의 물리적 특성을 분석하고, 새로운 감 수확기구를 개발하여 기존의 감 수확기구와 탈과력을 비교하였다. 그 결과를 요약하면 다음과 같다. 1. 과실의 무게와 과실-결과지계의 크기를 측정한 결과 과실의 무게는 평균 157 g이었고, 과경부는 장경이 평균 4.6 mm, 단경이 평균 3.7 mm로 나타났다. 또한 과경부 단면적은 평균 $13.9mm^2$이었고, 과경부 길이는 평균 13.6 mm로 나타났다. 2. 기존의 탈과장치의 탈과력은 최대 114.7 N, 최소 63.7 N, 평균86.3 N으로 나타났다. 3. 개발한 탈과장치의 탈과력은 최대 113.8 N, 최소 51.0 N, 평균 72.6 N으로 나타났다. 4. 평균 탈과력은 칼날형이 72.6 N이고 기존의 것이 86.3 N으로서 기존의 것이 칼날형보다 1.2배 큰것으로 나타났다. 5. 탈과력은 과경부의 단면적 증가에 따라 증가하였다.

• 한국초지조사료학회지
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• 제36권3호
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• pp.215-222
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• 2016

Nitrogen (N) fertilizer management is one of the important aspects of economic production of sorghums in sustainable agriculture. The aim of the study was to evaluate the effects of different N application rates and its split N application methods on productivity, growth characteristics, N accumulation, N use efficiency (NUE), and feed value of Sorghum ${\times}$ Sudangrass hybrids. Treatments consisted of five N application rates (0, 150, 200, 250, and $300kg\;ha^{-1}$) and two split N application methods (40% in basal N, 30% at the growing stage, and 30% after the first harvest vs. 50% in basal N and 50% after the first harvest). Plant height, leaf width, and stem diameter were increased ($p{\leq}0.05$) with increasing N fertility rates at each harvest. Chlorophyll content (expressed as SPAD values) was the highest at a rate of $300\;kg\;N\;ha^{-1)$ (first harvest, 46.32; second harvest, 33.09). It was the lowest at zero N (first harvest, 21.56; second harvest, 18.5). Total N, N uptake, and NUE were increased with higher N rates. Split N application had little effect on total N, amount of N uptake, or NUE. Total dry matter yields were the highest ($21,715\;kg\;ha^{-1}$) at a rate of $300\;kg\;N\;ha^{-1}$. It was the lowest ($10,054\;kg\;ha^{-1}$) at zero N. Our results suggest that more than $300\;kg\;N\;ha^{-1}$ can improve dry matter yield to be above 116% compared to zero N, thus enhancing the agronomic characters of sorghums. However, no significant effect had been found for split N application. Further work is needed to determine the optimal N levels and the effect of split N application rates.

• 한국약용작물학회지
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• 제5권4호
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• pp.284-288
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• 1997

농가(農家)에 보급(普及)된 수도용(水稻用) 콤바인의 이용효율(利用效率)을 높이고 농가소득 증대(農家所得 增大)에 기여(寄與)하기 위해 율무의 콤바인 수확적기(收穫適期)를 구명(究明)하고자 수확시기(收穫時期)를 개화기후(開花期後) 40일, 50일, 00일, 70일에 실시(實施)하시여 얻은 결과(結果)를 요약(要約)하면 다음과 같다. 1. 작업효율(作業效率)은 개화기후(開花期後) 50일 이후(以後)에는 2조 수확(收穫)) 가능(可能)하였고, 작업속도(作業速度)는 개화기후(開花期後) 50일 이후(以後)에는 0.26m/s였고 이론상의 작업능력(作業能力)은 개화기후(開花期後) 60日 이후(以後)는 11.23a/hr였다. 2. 수분함량(水分含量)은 수확시기(收穫時期)가 늦어질수록 낮아져 경엽(莖葉)의 수분함량(水分含量)은 $69.7{\sim}55.3%$ 였고, 종실(種實)의 수분함량은 개화기후(開花期後) 60일 이후(以後)에는 34.2%정도로 안정 되었다. 3. 수확시기(收穫時期)가 늦어질수록 등숙립(登熟粒)은 증가(增加)하였고, 미숙립(未熟粒)과 검불은 감소(減少)하였는데, 개화기후(開花期後) 60일 이후(以後)에는 검불의 혼입율이 1.8%미만이었다. 4. 개화기후 40일부터 70일까지 10일 간격으로 조사한 결과, l 중은 수확시기(收穫時期) 가 늦어질수록 무거워졌으나, 10a당(當) 종실수량(種實收量)은 개화기후(開花期後) 60일에서 가장 무거웠다. 5. 율무의 수도용(水稻用) 콤바인을 이용한 수확적기(收穫適期)는 회귀분석(回歸分析) 결과(結果) 개화기후(開花期後) 68 일경(日頃)이었다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.407-410
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• 2009

A piezoelectric device which converts mechanical vibration energy into electrical energy is able to harvest energy and the usable energy is mW ${\sim}$ W, hence a converter is necessary to acquire the energy efficiently. Various limited conditions should be considered for the design of AC/DC converter for energy harvesting of a piezoelectric device supplying small amount of energy. In addition to simple structure, compact size, light weight and high efficiency, the energy harvesting AC!DC converter should adopt the technique of self operating, in which only the harvested energy from the piezoelectric device is available. This paper proposes new AC/DC resonant boost converter to harvest efficiently electrical energy from mechanical vibration energy, analyzes the operating characteristics of the converter and proves its feasibility for energy harvester with PSPICE simulation and experiment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권4호
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• pp.1889-1910
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• 2017

This paper investigates a protocol so-called Adaptive Harvest Then Transmit (AHTT) for wireless powered communication networks (WPCNs) in multiple-input single-output (MISO) downlink systems, which assists in transmitting signals from a multi-antenna transmitter to a single-antenna receiver. Particularly, the power constrained relay is supplied with power by utilizing radio frequency (RF) signals from the source. In order to take advantage of multiple antennas, two different linear processing schemes, including Maximum Ratio Combining (MRC) and Selection Combination (SC) are studied. The system outage capacity and ergodic capacity are evaluated for performance analysis. Furthermore, the optimal power allocation is also considered. Our numerical and simulation results prove that the implementation of multiple antennas helps boost the energy harvesting capability. Therefore, this paper puts forward a new way to the energy efficiency (EE) enhancement, which contributes to better system performance.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.18-24
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• 2013

Purpose: This study was conducted to develop an optimal combine scheduling program using Max-Coverage algorithm which derives the maximum efficiency for a specific location in harvest seasons. Methods: The combine scheduling program was operated with information about combine specification and farmland. Four operating types (Max-Coverage algorithm type, Boustrophedon path type, max quality value type, and max area type) were selected to compare quality and working capacity. Result: The working time of Max-Coverage algorithm type was shorter than others, and the total quality value of Max-Coverage algorithm and max quality value type were higher than others. Conclusion: The developed combine scheduling program using Max-Coverage algorithm will provide optimal operation and maximum quality in a limited area and time.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1993년도 학술대회지
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• pp.155-163
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• 1993

An American ginseng(Panax quillquefolium L) industry has emerged in British Columbia, Canada over the past ten years. Interest has grown very rapidly and with this development, attention is now moving away from field production issues and emphasis is being directed to enhancements in ginseng storage, drying and processing. There is a dearth of knowledge on these aspects even though they are crucial to international competitiveness. Enhancement dicatates the application of a systems approach to optimizing the harvest and post - harvest production system(crop digging, pre - washing cold storage. washing, drying and post - drying storage). Research in British Columbia to date has focussed on drying and storage issues and has resulted in the design of an enhanced commercial drying system. The role of dryer management, loading rates, airflow rates and pre - drying cold storage on American ginseng root drying rates and root quality were examined. From the dryer management experiments, there are distinct advantages to size sorting root to yield optimum drying rates. If unsorted root is used, efficiency is increased if the trays are systematically rotated. Loading rate experiments illustrate that increasing rates above those currently used in commercial dryers are possible without any sacrifice in quality. This has significant implications for commercial drying. Pre - drying cold storage is a most significant tool for managing drying operations. Over a period of six weeks, no discernable decrease in quality was found as a consequence of cold storage. Further, the moisture loss and the associated root surface changes(loss of surface soil in storage for example) provide new challenges for root quality management. Continued research and technological innovation will be crucial in addressing the demanding challenges of the future.

• 한국식품과학회지
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• 제4권1호
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• pp.6-12
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• 1972

Fay Elberta freestone peaches were harvested at four maturity levels as judged by skin color and firmness. They were ripened at $68^{\circ}F$ under 80 percent relative humidity for 4, 6, 8 and 10 days respectively prior to canning. Results indicate that both harvest maturity and ripening conditions are important factors influencing quality, flavor and composition of canned freestone peaches. Peaches harvested at $18{\sim}24$ pounds on a Magness-Taylor pressure tester with a 7/16' plunger(M1) failed to ripen satisfactorily. Fruits harvested at $13{\sim}17$ pounds (M2) pressure test ripened successfully at $68^{\circ}F$ within 6 to 8 days; and those harvested at 6 to 12 pounds (M3) needed 4 days for ripening at $68^{\circ}F$. Tree-ripened fruits (M4) were undesirable for canning because of the high percentage of bruised fruits. The optimum firmness for canning appears to be in the range of 1.5 to 3.0 pounds. The titratable acidity of peaches decreased during maturation and ripening. The tannin content of peaches at M1 maturity decreased with ripening at $68^{\circ}F$. But no appreciable change was observed in the M2 and M3 series which were ripened at $68^{\circ}F$ for 4 to 10 days. The volatile reducing substances (V.R.S.) increased as the peaches developed on the tree and also during post-harvest ripening. The effect of harvest maturity and post-harvest ripening on color grade of the canned peaches is presented. Little difference was found in the flavor and composition of peaches peeled by the cup-down lye peeling and the steam-peeling methods. The cup-down lye-peeling method might be most advantageous because of its higher peeling efficiency.

• 한국작물학회지
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• 제49권3호
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• pp.179-183
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• 2004

호남지역 보리 2모작 재배농가의 생력화를 위하여 벼 수확 동시 보리파종에 따른 보리의 생육특성 및 생력효과를 조사ㆍ분석한 결과를 요약하면 다음과 같다. 1 벼 수확동시 보리파종은 벼 수확과 동시에 이루어지므로 관행 파종방법보다 5일 이상 빠르게 파종되었다. 2. 벼 수확동시 보리파종재배는 한발시 볏짚피복에 따른 재해 경감효과가 있었으며, 보리수확기 볏짚 C/N율은 31.6％로 낮아졌다. 3. 벼 수확동시 보리파종시 생육특성은 관행재배보다 수수는 감소하였으나 간장, 1수립수 및 천립중 등이 증가하였으며, 수량은 관행 재배보다 평균 6.5％ 증수하는 경향이었다. 4. 벼 수확동시 보리파종 작업시간은 파종작업 단계축소로 관행파종방법보다 작업시간이 58％절감되었으며, 경영비는 8％ 절감되었고, 소득은 16％ 증가하였다.