• 한국유기농업학회지
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• 제17권1호
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• pp.35-53
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• 2009

The theme-type self-harvest concept proposed in this research will be applied as a relevant reference in planning and realizing urban-rural exchange facilities at the village level. The aim of this paper is to describe the concept, to characterize the self-harvesters and organic farmers involved, to illustrate the ecological, economic and social interaction and the possible constraints of the concept. What is more important, however, is to develop programs for consultants, organic farmers and green-minded consumers, to vitalize direct transaction. The proponents of self-harvest are convinced that this concept leads to ecological, economic and social benefits, which will help to design a sustainable food supply system for small, medium and large cities.

• Fisheries and Aquatic Sciences
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• 제23권9호
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• pp.25.1-25.9
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• 2020

Fish is an extremely perishable food product which requires proper handling soon after harvest. The present study was aimed at assessing post-harvest fish losses and preservation practices in Siavonga district, Southern Zambia. Structured and semi-structured questionnaires were used to collect data on post-harvest fish losses and preservation practices from aquaculture producers, artisanal, and commercial fishers. All the fishers who landed on the lakeshore were interviewed, while aquaculture producers were randomly selected based on the information provided by the local department of fisheries. The results of the study revealed that all the fishers experienced post-harvest fish losses at varying degrees with those losing up to 10% of the total catch being in the majority. In contrast, aquaculture producers did not report any post-harvest fish losses. Most aquaculture producers commonly used chilling as preservation practice contrary to artisanal and commercial fishers who commonly used smoking and sun sun-drying respectively. Furthermore, fish product safety and quality control were poorly practiced in the district. Lack of cold storage facilities and fluctuating weather conditions were the major challenges impacting fish post-harvest activities. Therefore, to curb the loss of revenue due to post-harvest fish losses, we propose the introduction of new technology, self-development skills for fishing communities, and enhanced access to refrigeration facilities.

• 한국작물학회지
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• 제54권4호
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• pp.346-350
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• 2009

The cultivated radish (Raphanus sativus L.) is a major vegetable crop in the world wide and fast-growing species that grows inhabitats of six continents. It is very important to determine hybrid seed purity in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The use of random amplified polymorphic DNA (RAPD) markers for evaluating seed purity in $F_2$-hybrid radish cultivars demonstrated. One hundred eighty seeds from the F1 male and female harvest were subsequently screened for seed purity using 13 primers. The 13 primers result in 17 cultivar-specific bands and 23 variable RAPD bands scored for cultivar. RAPD analysis of hybrid seeds from the harvest revealed 128 seeds tested except underdevelopment and decayed seeds were sibs. Especially, $F_2$ hybrids of radish, OPC13, OPD20 were presented clear hybrid bands. It maintains higher than average level of genetic diversity compared with their correspondent parents. RAPD amplification of DNA extracted from germinated individuals from the female harvest reveal that 10 of 208 seeds tested were self-inbred (4.8%). RAPD analysis of hybrid seeds from the male harvest revealed 7 of the 208 seeds tested were sibs (3.4%). The RAPD may lead to a better insight in to the hybrid seed purity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.544-547
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• 2002

According to the rising of national economic level. domestic consumption of vegetables having high additive values is increased continuously due to increased consumption of meat in last decade. These vegetables are produced almost in this country and are limited to import from neighbor countries in due of high transportation expenses for storing in refrigerated container. It is very important to mechanize the harvest work, forming more than 30% for their production cost, in order to cultivate variable vegetables at the same time according to their harvesting seasons. In this state its former harvest methods, with using of human power or semi-automatic harvest, caused to increase their production cost due to high labor cost and low working efficiency. The former onion harvest being operated almost by semi-automatic plant distributer mechanism have many limit and troublesome for cultivation spaces, vinyle mulched ridge, gravel mixture in soil. Therefore, it is necessary to develope a fully automatic and self-running situation and overcome above handicaps, even in the farm covered with vinyle house or mulch sheets. This newly developed onion harvest can be applied to plant various young trees and will be able to export together with onion haying their competition in the worldwide market in which the culinary vegetable method or farm conditions is similar to our country.

• 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.

• Journal of Biosystems Engineering
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• 제41권1호
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• pp.12-20
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• 2016

Purpose: Pepper prices have risen continuously because of a decrease in cultivation area; therefore, mechanical harvesting systems for peppers should be developed to reduce cost, time, and labor during harvest. In this study, a screw type picking head for a self-propelled pepper harvester was developed, and the optimal working conditions were evaluated considering helix types, winding directions of helix, and rotational speeds of the helix. Methods: The screw type was selected for the picking head after analyzing previous studies, and the device consisted of helices and a feed chain mechanism for conveying pepper branches. A double helix and a triple helix were manufactured, and rotational speeds of 200, 300, and 400 rpm were tested. The device was controlled by a variable speed (VS) motor and an inverter. Both the forward and reverse directions were tested for the winding and rotating directions of the helix. An experiment crop (cultivar: Longgreenmat) was cultivated in a plastic greenhouse. The test results were analyzed using the SAS program with ANOVA to examine the relationship between each factor and the performance of the picking head. Results: The results of the double and triple helix tests in the reverse direction showed gross harvest efficiency levels of 60-95%, mechanical damage rates of 8-20%, and net marketable portion rates of 50-80%. The dividing ratio was highest at a rotational speed of 400 rpm. Gross harvest efficiency was influenced by the types of helix and rotational speed. Net marketable portion was influenced by rotational speed but not influenced by the type of helix. Mechanical damage was not influenced by the type of helix or rotational speed. Conclusions: Best gross harvest efficiency was obtained at a rotational speed of 400 rpm; however, operating the device at that speed resulted in vibration, which should be reduced.

• 한국약용작물학회지
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• 제23권4호
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• pp.311-318
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• 2015

This study had been conducted to investigate the effect of some plant growth regulators inducing fruit enlargement and optimal harvest time in Sageretia thea. Two hundred fifty $mg/{\ell}$ mepiquat chloride treatment, $1mg/{\ell}$ thidiazuron treatment on full bloom, and $200mg/{\ell}$ gibberellic acid treatment on 7 days before full bloom resulted in the increase of 21.7% in weight, and $200mg/{\ell}$ gibberellic acid treatment 7 days before full bloom, 10$mg/{\ell}$ forchlorfenuron treatment 14 days after full bloom, and $1mg/{\ell}$ thidiazuron treatment on full bloom also brought about positive effects on the enlargement of the fruit, increasing 6.3%, 6.3% and 8.1% in its transverse diameter, respectively. Furthermore, the effects of the plant growth regulator treatments on the harvest time of Sageretia thea were determined as follows: the increase in the optimal harvest time of 57.2 - 75.4%, shorter maturation period, by the treatments with $500mg/{\ell}$ mepiquat chloride 7 days after full bloom, $100mg/{\ell}$ gibberellic acid treatment on full bloom, $2.5mg/{\ell}$ forchlorofenuron 7 days after full bloom and $2mg/{\ell}$ thidiazuron treatment 7 days before full bloom; and the greater effects of plant growth regulator treatments on the fruit maturation in the following order, gibberellic acid > thidiazuron > forchlorofenuron > mepiquat chloride. The results of this study are expected to be used as a reference data to develop Sageretia thea as a new local specific crop for Jeju island.

• 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.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.10-10
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• 2022

The concern about food security is rising as the unstable situation of food supply and demand due to the Covid-19 pandemic, climate change, and turbulent political situation. Korea's global food security index (GFSI), analyzed by the Economist Group, is considered good, but the level continuously decreases in comparing food security levels by country. In particular, Korea is highly dependent on food imports, and food and grain self-sufficiency rates continuously decrease. Therefore, increasing those rates to strengthen food security is urgent. Among the major grains, the self-sufficiency of wheat, com, and soybeans, except rice, is relatively low. Unlike the decrease in the annual rice consumption, the annual wheat consumption has been continuously maintained or increased, which is required public-private efforts to increase the self-sufficiency rate of wheat. Applying the government's policies implemented to increase the self-sufficiency rate of rice in the past will help increase the self-sufficiency rate of wheat. In other words, expanding wheat production and infrastructure, stabilizing supply and demand, and establishing a distribution system can be applied. However, the processing capability of wheat and rice is different, which is necessary to improve wheat quality and processing technology to produce consumer-preferred wheat-based products. The wheat and flour quality can be improved through breeding, cultivation, post-harvest management, and milling. In addition, research on formulation, processes, packaging, and storage to improve the quality of wheat-based products should be done continuously. Overall, food security could be strengthened by expanding wheat production and consumption, improving wheat quality, and increasing wheat self-sufficiency.

• Smart Structures and Systems
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• 제20권3호
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• pp.285-301
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• 2017

This paper presents the design and the application of a new self-powered hybrid electromagnetic damper that can harvest energy while mitigating the vibration of a structure. The damper is able to switch between an energy harvesting passive mode and a semi-active mode depending on the amount of energy harvested and stored in the battery. The energy harvested in the passive mode resulting from the suppression of vibration is employed to power up the monitoring and electronic components necessary for the semi-active control. This provides a hybrid control capability that is autonomous in terms of its power requirement. The proposed hybrid circuit design provides two possible options for the semi-active control: without energy harvesting and with energy harvesting. The device mechanism and the circuitry that can drive this self-powered electromagnetic damper are described in this paper. The parameters that determine the device feasible force-velocity region are identified and discussed. The effectiveness of this hybrid damper is evaluated through a numerical simulation study on vibration mitigation of a bridge stay cable under wind excitation. It is demonstrated that the proposed hybrid design outperforms the passive case without external power supply. It is also shown that a broader force range, facilitated by decoupled passive and semi-active modes, can improve the vibration performance of the cable.