• 한국포장학회지
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• 제29권3호
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• pp.223-228
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• 2023

Sustainable energy supplies without the recharging and replacement of the charge storage device have become increasingly important. Among various energy harvesters, the triboelectric nanogenerator (TENG) has attracted considerable attention due to its high instantaneous output power, broad selection of available materials, eco-friendly and inexpensive fabrication process, and various working modes customized for target applications. In this study, the amount of voltage and current generated was measured by applying the PSD profile random vibration test of the electronic vibration tester and ISTA 3A according to the time of Anodized Aluminum Oxide (AAO) pore widening of the manufactured TENG device Teflon and AAO. The discharge and charging tests of the integrated module during the random simulated transport environment and the recognition distance of RFID were measured while agricultural products (onion) were loaded into the returnable folding plastic box. As a result, it was found that AAO alumina etching processing time to maximize TENG performance was optimal at 31 min in terms of voltage and current generation, and the integrated module applied with the TENG module showed a charging effect even during the continuous use of RFID, so the voltage was kept constant without discharge. In addition, the RFID recognition distance of the integrated module was measured as a maximum of 1.4 m. Therefore, it was found that the surface condition of AAO, a TENG element, has a great influence on the power generation of the integrated module, and due to the characteristics of TENG, the power generation increases as the surface dries, so it is judged that the power generation can be increased if the surface drying treatment (ozone treatment, etc.) of AAO is applied in the future.

• 한국토양비료학회지
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• 제28권4호
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• pp.301-305
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• 1995

논토양(土壤) 경운(耕耘) 및 관기방법(灌漑方法)에 따른 토양(土壤)의 물리적특성(物理的特性)과 수도생육(水稻生育)의 차이(差異)를 구명(究明)하고자 석천통(石泉統)에서 무경운(無耕耘) 건답(乾畓), 무경운(無耕耘) 담수(湛水), 경운(耕耘) 건답(乾畓), 경운(耕耘) 담수구(湛水區)와, 관행(慣行)(기계이앙경운(機械移秧耕耘)-로타리) 등(等)의 5개(個) 처리구(處理區)를 두고 수도(水稻)를 3년간(年間) 재배(栽培)하면서 토양(土壤)의 물리적특성(物理的特性)과 수도생육(水稻生育)을 조사(調査)한 시험결과(試驗結果)는 다음과 같다. 토양(土壤)의 가비중(假比重)과 경도(硬度)는 경운구(耕耘區)보다는 무경운구(無耕耘區), 담수구(湛水區)보다는 건답구(乾畓區)에서 높았다. 무경운(無耕耘), 건답구(乾畓區)의 투수원도(透水速度)는 경운비토구(耕耘碑土區)보다 56% 빨라 전관개기간중용수량(全灌漑期間中用水量)이 27% 증가(增加)되었으나, 무경운구(無耕耘區)에서는 관행구(慣行區)보다 낙수기이후(落水期以後) 수분감소(水分減少)가 빨라 농기계(農機械) 작업(作業)이 유리(有利)한 조건(條件)이었다. 층위별(層位別) 뿌리분포(分布)를 보면 무경운구(無耕耘區)는 주로 표토(表土)에 분포(分布)하였다. 출수기(出穗期)는 무경운구(無耕耘區)가 경운구(耕耘區)보다 2일(日)정도 빠르고 건답구(乾畓區)가 담수구(湛水區)보다는 3일(日) 빨랐다. 처리별(處理別) 수도생육(水稻生育)은 건답구(乾畓區)보다는 담수구(湛水區)에서 양호(良好)하였고 줄기매몰(埋沒) 깊이는 무경운담수구(無耕耘湛水區)에서 지상부(地上部)로 0.9cm 올라와서 도복(倒伏)의 위험(危險)이 있었다. 무경운시(無耕耘時) 3년(年) 평균(平均) 정조수량(正租收量)은 건답구(乾畓區) 및 담수구(湛水區)가 각각(各各) 5.55M/T/ha, 5.16M/T/ha로써 관행구(慣行區) 6.31M/T/ha 보다 각각(各各) 12.0%, 18.2% 감수(減收)되었으며 대체로 무경운시(無耕耘時)는 건답구(乾畓區), 경운시(耕耘時)에는 담수구(湛水區)에서 수량(收量)이 많은 경향(傾向)이었다.

• 한국직업건강간호학회지
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• 제14권2호
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• pp.93-107
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• 2005

Purpose: The purpose of this study is to identify the trends of studies on work-related musculoskeletal disorder and to suggest the direction of future research. Method: 144 research thesis for a degree on work-related musculoskeletal disorder were systematic reviewed and published from Jan. 1990 to Mar. 2005. The analyzed using descriptive statistics, an actual number, percentage. Result: As its result the work-related musculoskeletal disorder research which is announced from domestic the doctorate dissertation at the 2004 year 42 the most many 144 dissertation middle most to be 129 in master degree dissertation was 15 in Ph D degree. Dissertation contents character the contents against the result relation that it analyzes especially and a condition and an obstacle was many most at 84. Research plan in most description investigation research 121 the dissertation field to be the especially public health (hygiene, industry and environment) at this 57 most many research object person distribution manufacturing industry in the research object one dissertation was many most at the 40. The tools which are used in each measurement in the question tool which it uses most the question price of land which uses the condition investigation ticket which it made from the NIOSH and the ANSI most many 33, the hazard which analyzes a work attitude in the tool which it uses the RULA was many most at 14. In the stress test tool social psychological healthy measurement PWI (Psychological Wellbeing Index) the dissertation which uses the Job Strain of the Karasek Model to be many most at 19 PWI (Psychological Wellbeing Index) 7 easy use. Work-related musculoskeletal disorder measurement hazard in physiological index and the machinery and tools which it uses there were 9 researches to use an electromyogram most plentifully. With the effect goes to a work-related musculoskeletal disorder they are 33 where the age is many most from general quality. From healthy act with the relation of smoking the year to be many from 16 dissertations. Work of the corpse an attitude (the attitude which is inappropriate) with 5 and the work market the work burglar is many most at 9, the society-support of 36 where the stress is many psychologically most, the stress and service also the most many duty discretion (authority and autonomy) is 6 at the duty demand boat song 9. The service career to be many is 22 of extraordinarily with relation of service. Conclusion: It is recommended the research which it sees being limited in only domestic thesis for a degree the international comparative study to become accomplished. It comes to think with the fact that it will be necessary to make the protocol which it conforms in the civil official guide the test researches for the protocol or arbitration program which is standardized are necessary. Prevention and the civil official of work relation bones and sinews standing total disease hazard scientific base one program is necessary with base.

• 한국토양비료학회지
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• 제47권5호
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• pp.374-380
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• 2014

To estimate greenhouse gas (GHG) emission, the inventory of rice cultivation at the farming without agricultural chemicals was established from farmers in Gunsan, Jeonbuk province in 2011~2012. The objectives of this study were to calculate carbon footprint and analyse the major factor of GHGs. To do this, we carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we suggested agricultural methods to reduce GHGs that can be appled by farmers at this region. At the farming system without agricultural chemicals, carbon footprint of rice production unit of 1 kg was 2.15 kg $CO_2.-eq.kg^{-1}$. Although the amount of carbon dioxide ($CO_2$) emission was the largest among GHGs, methane ($CH_4$) emission had the highest contribution to carbon footprint on rice production system when it was converted to carbon dioxide equivalent ($CO_2-eq.$) multiplied by the global warming potential (GWP). Main source of $CO_2$ emission in the rice farming system without agricultural chemicals was combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ was emitted during rice cultivation practice and its major emission factor was flooded paddy field in anaerobic condition. Also, most of the $N_2O$ was emitted from rice cultivation process. Major sources of the $N_2O$ emission was application of fertilizer such as compound fertilizer. As a result of sensitivity analysis in energy consumption, diesel had the highest sensitivity among the energy inputs. With the reduction of diesel consumption by 10%, it was estimated that $CO_2$ potential reduction was about 2.0%. With reducing application rate of compound fertilizer by 10%, the potential reduction was calculated that $CO_2$ and $N_2O$ could be reduced by 0.5% and 0.9%, respectively. At the condition of 10% reduction of silicate and compost, $CO_2$ and $CH_4$ could be reduced by 1.5% and 1.6%, respectively. With 8 days more drainage than the ordinary practice, $CH_4$ emission could be reduced by about 4.5%. Drainage and diesel consumption were the main sources having the largest effect on the GHG reduction at the farming system without agricultural chemicals. Based on the above results, we suggest that no-tillage and midsummer drainage could be a method to decrease GHG emissions from rice production system.

• 한국정보전자통신기술학회논문지
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• 제10권4호
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• pp.350-357
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• 2017

본 연구는 선행 연구로 진행되었던 수직상승형 고소작업차의 개발을 위한 구조해석 및 원격 제어를 포함한 중앙집중식 컨트롤러 및 유압식 상승리프트 개발에 관한 사후 연구로 진행되었다. 기존에 연구를 진행하면서 개발하였던 고소리프트의 구조 변경을 통하여 안전성 검토를 실시하였다. Solidworks로 3D 모델링을 진행하였으며, Hypermesh S/W를 통하여 유한요소의 모델을 생성하였다. 또한, 평가를 위한 작업차의 적재 환경은 작업 테이블에 위치별(전체, 상좌, 상우, 하좌, 하우)로 적재량이 250 kg인 조건, 작업 테이블에 위치별(전체, 상좌, 상우, 하좌, 하우)로 적재량이 600kg인 조건으로 하여 구조해석을 진행하여 다방면으로 안전성을 검토하였다. 그 결과 허용 적재량 250 kg과 초과 적재량 600 kg에 대해서 최대응력이 발생하는 부품을 제외한 결과를 살펴보면(Case-11 제외), 응력 수준은 항복강도 이하임을 알 수 있다. Case-11의 경우에는 최대응력이 발생하는 부품을 제외한 후에도 상단의 안전바 중앙 지지부에서 항복강도를 초과하는 영역이 존재하지만, 최대응력이 발생하는 부품과 같이 전체 구조물의 안전성 측면에는 영향을 미치지 않을 것으로 사료된다. 변위(처짐) 결과를 살펴보게 되면, 모든 경우에 있어서 동일하게 테이블에서 최대 처짐이 발생하는 것을 알 수 있으며, 250 kg과 600 kg 모두 처짐이 발생하는 경향은 동일한 것으로 나타났다.

• 자원리싸이클링
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• 제15권1호
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• pp.46-57
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• 2006

폐기물고형연료(RDF : Resused Derived Fuel)를 연료로 하는 연소기술의 개발을 위하여 기포유동층 연소로와 순환유동층 연소로, 연속연소식 연소로, 회분식 연소로 등 다양한 연소장치를 이용하여 연소 특성실험을 하였다. 여러 종류의 연소설비에서 RDF의 연소 및 배출가스 특성을 비교, 분석하였으며 RDF 전용 연소설비에 대하여 보다 깊은 연구의 기초 자료로 활용하자고 하였다. 기포 유동층 및 순환유동층연소로에서는 적정투입량과 가스공탑속도등 적정운전조건에 따라 안정적인 연소가 이루어지는 것을 확인할 수 있었다. 순환유동층 연소로에서 연소조건에 따라 연료 중의 질소성분과 연소공기 중의 산소와의 반응이 커져서 NOx의 농도가 높아지는 것을 알 수 있었으며 $SO_2$는 매우 낮은 농도로 측정되어 RDF의 유동층 연소시 거의 발생하지 않는 것으로 판단되었으며, HCl의 경우 평균 36.4ppm으로 배출허용기준치보다는 낮으나 저감대책이 필요한 것으로 판단되었다. 연속연소식 연소로와 회분식 연소로의 경우 성형 RDF와 fluff RDF를 비교 실험한 결과 높은 밀도를 가진 성형 RDF의 연소가 안정적인 열회수 측면에서 더 유리한 것을 알 수 있었으며 배가스 특성은 비슷한 값을 나타내었으며 배출가스 특성은 비슷하였다.

• 생물환경조절학회지
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• 제5권2호
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• pp.174-186
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• 1996

This study was carried out in order to understand the plan, design, constructing and actual condition of management of modernized horticultural facilities in Kyungpook Province which had been constructed from 1992 to 1995 funded by Government support. The aim of this study is to provide reference data for success of the forth project. It was performed by making up a question about driving of project and management condition of equipment after constructing. The results obtained from this study are as follows: 1. 73.5% of facilities horticulture farmhouse recognized that the prospect of greenhouse is bright, but 92.5% of the farmhouse also recognised that they need technical consultation on protected horticulture farming. Therefore, technical educations would must be enhanced about foundation of greenhouse and cultivation technique. 2. The holding times of explanatory meetings, cause of understanding to farmhouse, were one or two times in greenhouse construction, and 62.5% of the farmhouse expressed the insufficiency at the explanation and educational data. For this reason, it was judged that the construction contract had been delayed more than 5 months in 49.3% of the farmhouse after the decision of project budget. 3. In constructing after a contract, the rates of construction delay is 53.4% and defect occurrence is 41.1%. The biggest reasons of construction delay was insufficiency of worker and materials supply. Each percentage is 29.1%. And the reason of defect occurrence is badness of machinery equipment(62.9% ). 4. In management of greenhouse, a pipe-constructed plastic film greenhouse changes plastic film every one and three years because of sticking dust on plastic film. It was needed to about in cleaning technique of coverings. Because that used 3-5 years only half of the expected life span. 5. The order of broken rating in the subsidiary equipment is like this lollop ventilator (42.8%), a general control system(33.3%) especially, in the case of a general control system, the rate of all family can control is 52.7%. so, it is time to develop easy control equipment which every one could use as soon as possible. 6. When choose heat generator as decide capacity, the most priority is the mount of heat generator the percent is 45.5% heat generator and as decide model, the private purchase's percent is 77.3%. It is higher than a public bidding heat generator the percent is 22.7% heat generator when it compare with a public bidding. In the case of $CO_2$ generator, using rate is only 19.0%. The using rate is very low, so it needs education how to use depends on the way of the subsidiary equipment. 7. In the case of seedlings, it is asked to use factory-processed seedling effectively. because it's difficult to get security of labors(58.8%), hoped crops (55.9%) access same crops(29.4%) much more and changing of crops depends on market situation. that is the main reason the lack of knowhow.

• Journal of Biosystems Engineering
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• 제2권2호
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• pp.37-45
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• 1977

Solar energy is a potential source of power that offers much promise being used for low-temperature applications like drying farm crops, space heating, and water heating for domestic uses. Already much of it are being used for those purpose in foreign countries. However, very little research has been done to determine the possibility of using the solar energy in Korea. This study was conducted to develop the general prediction equation of the total radiation on a horizontal surface in Daejeon area based on 5 years 91972, Jun.1-1976. Dec.31) meteorological data (bright sunshine hours, average total horizontal radiation), and to obtain experimentally the thermal efficiency of solar air and water collectors, which will be used as a basic data of designing flat-plate solar collector system.In addition to the thermal efficiency of the collectorsthe relationship among those factors affecting it such as weather condition, orientation factor, and tilted angle of collector was analyzed. The results of this study were as follows. 1. The general predicted equation of the total radiation on a horizontal surface in Daejeon area based on bright sunshine hours was developed as $H_{av} =(1.546\frac{n}{N}-0.582)H_o$. Predicting the total radiation on a horizontal surface by the above equation was thought to be possible because to values of 0.882 was smaller than any t values at above 0.05 level on the basis of two tailed test of the difference between the calculated and the recorded values. 2.It was observed that optimum tilt angle of the collector in the summer and the autumn drying season was 13 degrees and 51 degrees respectively, these values could be obtained by adding or substracting approximately 25 degrees from the latitude of this area $(36.3^{\circ}N)$ .The relationship between orientation factor and declination of sun at suitable tilt angle of 33 degrees $(s=0.9\O)$ was shown at Fig.4. 3.The thermal efficiency of solar wdter collector was shown 13.4-51. 6% on Aug. 15 (the minimum radiation recorded) and 43.8 ~537% Aug.20 (the maximum radiation recorded), and 13.8~ 46.6 and 44.3~ 49.7 were shown on each corresponding day. 4.The thermal efficiency of the collectors according to the weather condition was shown a big difference of about 10% between the day of the maximum radiation recorded and the minimum, but the differen of efficiency between the air and the water collector was at most 2 ~ 3%. 5. Even if the efficiency of the solar water collector was a little higher than the solar air collector, for drying farm products, the solar air collector was thought to be more effective because the air heated by collector could be directly used for drying them.

• 폴리머
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• 제36권5호
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• pp.555-563
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• 2012

사출 성형품에서 발생되는 뒤틀림은 성형공정 중 제품의 불균일한 수축과 잔류응력의 이완으로 인하여 나타나는 현상이다. 휨이나 뒤틀림 현상을 방지하기 위해서 성형품이 강성이 있도록 설계하거나 수지에 유리섬유 등으로 보강하여 사용한다. 본 연구에서는 플라스틱의 성형품에서 성형품의 설계에 따른 뒤틀림 현상을 성형조건 별로 알아보았다. 성형품의 설계는 리브로 보강된 두 종류와 보강 리브가 없는 시편을 사용하였다. 수지는 유리섬유로 보강된 비결정성 수지인 PC와 ABS를 사용하였다. 실험결과 휨은 리브의 설계에 따라 큰 변화를 보였다. 게이트 주변, 게이트 반대쪽, 그리고 흐름방향쪽 등 측정위치에 따라서 휨은 다양하게 나타났다. 이러한 휨의 결과는 유리섬유의 배향과도 크게 관련이 있음을 컴퓨터 해석을 통해 확인할 수 있었다. 리브가 없는 단순 평판에서 휨이 가장 작게 나타났으며, 리브가 흐름방향으로 놓여있는 경우가 휨에 대한 큰 저항을 보였다. 시편에 나타난 휨은 성형조건보다는 제품의 설계에 따라 크게 변하였다. 리브의 설계와 그에 따른 게이트의 위치 설정은 유리섬유의 배향과 직접적인 관련이 있으므로 성형품의 휨 조절에 매우 중요함을 보여주었다.

• Journal of Biosystems Engineering
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• 제6권2호
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• pp.9-19
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• 1982

소형(小型) 디젤엔진의 예연소실(豫燃燒室) 형상(形狀)이 저온시(低溫時)의 시동성(始動性)에 미치는 영향(影響)을 구명(究明)하기 위해 8종(種)의 예연소실(豫燃燒室)과 2종(種)의 실린더헤드를 제작(製作)하여 $2^7$ 요인실험법(要因實驗法)에 의해 1회(回) 조작시(操作時) 최저(最低) 시동가능(始動可能) 온도(溫度), 최대출력(最大出力), 전부하(全負荷)(4/4) 및 과부하(過負荷)(11/10)시(時)의 연료소비율(燃料消費率)을 측정(測定)하여 분석(分析)한 결과(結果)를 요약(要約)하연 다음과 같다. 가. 피스톤 상면(上面)에 대한 주분사구(主噴射口)의 상대각도(相對角度)가 $20^{\circ}$에서 $18^{\circ}$로 감소(減少)하면 최저(最低) 시동가능(始動可能) 온도(溫度)가 약(約) $2.4^{\circ}C$ 낮아졌으며 최대출력(最大出力)은 약(約) 0.3ps 증가(增加)되었다. 나. 실린더헤드 홈 각도(角度)가 $20^{\circ}$에서 $18^{\circ}$로 작아짐에 따라 최저(最低) 시동가능(始動可能) 온도(溫度)가 약(約) $3.3^{\circ}C$ 낮아졌으며, 최대출력(最大出力)은 약(約) 0.3ps 감소(減少)되었다. 다. 예연소실(豫燃燒室) 길이가 17.5mm에서 15.5mm로 짧아지면 최저(最低) 시동가능(始動可能) 온도(溫度)가 $2^{\circ}C$ 낮아졌으며 최대출력(最大出力)은 0.2ps정도(程度) 감소(減少)되었다. 라. 주분사구(主噴射口) 직경(直俓)이 4.8mm에서 4.5mm로 작아지면 최대출력(最大出力)은 0.2ps정도(程度) 증가(增加)했으나, 주분사구(主噴射口) 직경(直俓)만이 변화(變化)에 따른 시동성(始動性)의 차이(差異)는 인정(認定)되지 않았다. 마. 주분사구(主噴射口) 각도(角度)가 $47^{\circ}$이고 실린더헤드 홈 각도(角度)가 $18^{\circ}$일 경우(境遇) 시동가능(始動可能) 온도(溫度)가 가장 낮았으며, 주분사구(主噴射口) 직경(直俓)이 4.5mm이고 예연소실(豫燃燒室) 길이가 17.5mm일 경우(境遇) 최대출력(最大出力)도 가장 높았고, 전부하(全負荷) 및 과부하시(過負荷時)의 연료소비율(燃料消費率)도 가장 낮았다. 바. 실린더 헤드홈 각도(角度)와 주분사구(主噴射口)의 각도(角度)가 각각(各各) 시동성(始動性) 향상(向上)에 가장 큰 영향(影響)을 미쳤으며, 또한 주분사구(主噴射口) 직경(直俓)과 예연소실(豫燃燒室) 길이와의 교호작용(交互作用)이 최대출력(最大出力)에 가장 큰 영향(影響)을 미쳤으므로 이들 요인(要因)에 대한 처리수(處理數)를 늘려 시험(試驗)해 볼 필요성(必要性)이 있는 것으로 사료(思料)된다. 사. 본(本) 실험(實驗)에서 최적조건(最適條件)으로 나타난 시작(試作) 예연소실(豫燃燒室)은 기존(旣存) 예연소실(豫燃燒室)보다 약(約) $-6^{\circ}C$의 시동성(始動性) 향상(向上)을 나타냈다.