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A Study for Farmers to Reduce Work Load on the Different Working Conditions (part I) - Cultivating Lettuce in the Winter Greenhouse - (농민의 작업환경별 노동부담 경감방안에 관한 연구(I) -겨울철 비닐하우스에서 상추재배 작업을 중심으로-)

  • 김명주;최정화
    • Korean Journal of Rural Living Science
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    • v.8 no.2
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    • pp.111-117
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    • 1997
  • In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads. and to grope for efficiency of agricultural works. For this we examined the actual conditions of working environment, farmer's clothes, working posture, working methods, working time, resting state, fatigue recovery methods during cultivating lettuce in the winter greenhouse. And Ive improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured, compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual conditions of cultivating lettuce in the winter greenhouse, farmers have experienced physical and mental chronic fatigue on the basis of the hot and humid crops-centered working environment, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy-weared habits. and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the positive effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by improving the hot and humid working environment, eliminating the hillock and obstacles of working path. deliver way, arranging the working stand and sorter consistantly, decreasing the clothing weight, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

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A Study for Farmers to Reduce Work Load on the Different Working Conditions (part II) - Cultivating Welsh Onion in the Summer Ground - (농민의 작업환경별 노동부담경감방안에 관한 연구(II) - 여름철 노지에서 대파재배 작업을 중심으로 -)

  • 김명주;최정화
    • Korean Journal of Rural Living Science
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    • v.8 no.2
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    • pp.119-124
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    • 1997
  • In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads, and to grope for efficiency of agricultural works. For this we examined the actual working conditions of cultivating welsh onion in the summer ground. And we improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured. compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual working conditions of cultivating welsh onion in the summer ground, farmers have experienced physical and mental chronic fatigue on the basis of farmer's appel to eye - fatigue and sun - burned skin on hot working environment including excessive ultraviolet rays, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy - weared habits, and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by eliminating the hillock and obstacles of ground, decreasing the clothing weight, using proper clothing appliances such as hat and sunglasses, controlling height of working stand and sorter suitably, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

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A Perceptual Study on the Temporal Cues of English Intervocalic Plosives for Various Groups Depending on Background Language, English Listening Ability, and Age (언어별, 연령별, 수준별 집단에 의한 모음간 영어 파열음 유/무성 인지 연구)

  • Kang, Seok-Han
    • Speech Sciences
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    • v.13 no.2
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    • pp.133-145
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    • 2006
  • In order to understand the various groups' perceptual pattern in both VCV trochee and iambus, this study examined the identification correctness and cue robustness for the unit intervals in light of background language, age, and English listening ability. The 4 groups of Native Speakers of English, Korean College Students of High Listening Achievement, Korean College Students of Low Listening Achievement, and Korean Elementary Students took part in the experiments. Tokens of $/d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per$ in trochee and of $/{\eth}{\partial}\;p{\ae}d,\;{\eth}{\partial}\;b{\ae}d,\;{\eth}{\partial}\;t{\ae}d,\;{\eth}{\partial}\;d{\ae}d,\;{\eth}{\partial}\;k{\ae}d,\;{\eth}{\partial}\;g{\ae}d/$ in iambus were extracted and modified into experimental signals composed of two digits(voiced-1, voiceless-0) by following the temporal intervals, in which the signals consisted of preceding vowel, closure, VOT, and post-vowel. In the first experiment of identification correctness in VCV iambus environment, all groups showed almost 100% correctness rate, while in trochee environment all groups were different(native speaker 87%, college high 74%, college low 70%, elementary 65%). In the second experiment of cue robustness, all groups showed the similar perceptual pattern in both environments. There was the order of robustness cues in VCV trochee: pre-vowel ${\gg}$ closure ${\gg}$ VOT ${\gg}$ post-vowel, while the order in VCV iambus: VOT ${\gg}$ post-vowel ${\gg}$ closure ${\gg}$ pre-vowel. In some condition, however, we found moderately different perceptual pattern depending on language, age and listening level.

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A Study on the Design of Door Module PNL Using CAE and Inverse Compensation for Warpage (휨방지를 위한 CAE와 역보정을 이용한 Door Module PNL설계에 관한 연구)

  • Kim, Doo-Tae;Han, Seong-Ryeol
    • Design & Manufacturing
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    • v.12 no.2
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    • pp.27-33
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    • 2018
  • Korea's automobile industry, which has grown rapidly to become the world's fifth-largest automobile producer, To cope with environmental pollution and energy problems in order to prevail competitive edge in global market We are investing a lot of research personnel and costs. Among them, for realizing alternative light weight It is a part of the automobile module system that has achieved the technological development before the breakthrough in the injection molding process in the press process. Door module PNL was the subject of research. The door module PNL is expected to cause warpage before the mold production due to the thin and flat product characteristics and fiber orientation characteristic of the material. In this paper, CAE analysis and reverse correction tool Design. CAE analysis to obtain the results of weld line position, bending position and deformation value Through the correction tool, think3, the original product was modified before the mold production to improve the completeness of the parts. In fiber orientation, the position and size of the cooling channel in the mold, the position and size of the gate, Temperature, pressure, time, and work environment. Compared with the result of CAE analysis, the product that was reverse-corrected by Think3 was manufactured, and injection molding was performed. Injection molding products were tested 24 hours later. 3.5 mm to 7.0 mm, and under the fixed condition, the deviation was from 1.1 mm to 1.5 mm. Unlike the CAE analysis, the deviation of the actual injection pressure and the cooling temperature, the fiber orientation of the material, In order to solve this problem, it is necessary to compare the injection conditions with the database, I knew I had to catch the standard.

The Function of Leaf Sheath on Growth and Development of Gladilous (글라디올러스의 생육에 미치는 엽초의 역할)

  • Jung, Woo-Yoon;Chang, Young-Deug;Ahn, Hyung-Geun;Choi, Sang-Tai;Park, In-Hwan
    • Current Research on Agriculture and Life Sciences
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    • v.21
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    • pp.17-21
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    • 2003
  • This study aimed to identify leaf sheath function through the investigation of effect of removal times and removed number of leaf sheath on growth and flowering in gladiolus. The leaf sheath influenced on the growth and flowering regardless of light condition at early growth stages. When total leaf sheath were removed in early growth stages, flower stalk length and spike length remarkably decreased. Whereas days of flowering were little different by leaf sheath removal. Also when removed numbers of leaf sheath were 1, 2 and 3, the growth and flowering were little different compared to control. But when removed numbers of leaf sheath were 4, flower stalk length decreased above 25cm compared to others treatment, spike length and number of flower decreased and stem diameter became thick abnormally.

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Performance Comparison of Flooded Seawater Cooling System with respect to Heat Sink Temperature (열원수 온도에 따른 만액식 해수냉각시스템의 성능 비교)

  • Yoon, Jung-In;Choi, Kwang-Hwan;Son, Chang-Hyo;Kang, In-Ho;Kim, Chung-Lae;Seol, Sung-Hoon
    • Journal of Power System Engineering
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    • v.20 no.2
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    • pp.91-96
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    • 2016
  • A fleet consists of a main vessel, light vessels and carrying vessels for purse seine fishery. Carrying vessels contains fish storages to maintain freshness of catches. Currently most carrying vessels applies the cooling system using plain ice though accompanied various shortcomings. Seawater cooling system directly chilling seawater are now in use on carrying vessels in some developed countries to make up for these shortcomings and maximize advantages. This research deals with necessity of seawater cooling systems and establishes system criteria using Aspentech HYSYS program, prior to an experiment of compact-scale seawater cooling system which now in progress of manufacture. Performance comparison on condensation capacity, mass flow rate of working fluid, compressor power input, pump power input and others of the seawater cooling system applying a flooded evaporator is conducted with respect to the temperature of surface seawater varying according to seasons. The result presents that mass flow rate circulating the system is increased about 16.7% as the temperature of surface seawater increases. At the same condition, condensation capacity and compressor input work also increase about 9.8% and 91.2%, respectively.

Torque Measurement of Rotating Shaft Using Fiber Bragg Grating Sensors and Rotary Optical Coupler (광섬유격자센서와 회전광학커플러를 사용한 새로운 회전축의 토크 측정방법)

  • Lee, Jong-Min;Hwang, Yo-Ha
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.12
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    • pp.1195-1200
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    • 2007
  • Torque of a rotating shaft has been mostly measured by strain gages combined with either a slip ring or telemetry. However, these methods have severe inherent problems like low S/N ratio, high cost, limited number of channels and difficult installation. In this paper, a new method using FBG(fiber bragg grating) sensors and a rotary optical coupler for online non-contact torque monitoring is suggested. FBG sensor can measure both strain and temperature, and has much batter characteristics than those of a strain gage. A rotary optical coupler is a optical connecting device between a rotating shaft and stationary side without any physical contact. It has been devised for transmitting light between a rotating optical fiber and a stationary optical fiber. The proposed method uses this rotary optical coupler to connect FBG sensors on the rotating shaft to instruments at stationary side. And a reference FBG sensor is also applied to compensate the insertion loss change of the rotary optical coupler due to rotation. Three FBG sensors have been fabricated in a single optical fiber. Two FBG sensors are attached on the shaft surface to measure torque and one sensor is installed at the shaft center to compensate the insertion loss change. The torque of a rotating shaft has been successfully measured by the suggested method proving its superior performance potential.

Strengthening the Occupational Exposure Limit for 1-Bromopropane according to the Results of Epidemiological Studies and Exposure Status (1-브로모프로판의 노출 실태와 역학조사에 따른 노출기준 강화에 관한 연구)

  • Ha, Kwonchul;Kim, Seung Won;Phee, Young Gyu;Lee, Naroo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.3
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    • pp.270-279
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    • 2020
  • Objective: The aim of this study was to propose revision of the occupational exposure limit(OEL) for 1-Bromopropane(1-BP) following a review of the appropriateness of the standard in light of increasing epidemiological data and handling risk. Materials and Methods: The results of toxicity and epidemiologic investigations for 1-BP and agencies' OELs were compared and reviewed through a literature review. In order to investigate the status of 1-BP handling in South Korea, data from work environment actual condition survey results and work environment measurement results were used. Results: The toxicity of 1-BP, such as central nervous system(CNS) damage, peripheral neuropathy, hematological adverse effects, and developmental and reproductive toxicity(male and female) has been reported. ACGIH recommends 0.1 ppm as a TLV-TWA value, but the OEL of South Korea stands at 25 ppm, which is 250 times higher than the TLV-TWA. Although 1-BP is a specially managed substance under the Industrial Safety and Health Law, the currently applied OEL cannot be said to be a safe level based on the results of epidemiological studies to date. In a work environment measurement in 2017, the total number of samples was 626, which were derived from 78 industries, and the average concentration was 1.173 ppm(standard deviation 2.88). Conclusions: To protect the health of workers handling 1-BP, estimated to be 780 in South Korea, it is necessary to strengthen the OEL(TWA) to a level of 0.3 ppm(lower than the 0.34 ppm with known toxic effects), which is believed to be safe as a result of epidemiological investigation. "Skin" notation should be recommended.

Optimum Condition for Mass Culture of Hairy Roots from Artemisia sylvatica MAX (국내 자생 그늘쑥 (Artemisia sylvatica MAX) 모상근의 대량배양을 위한 최적조건)

  • Shin, Sun-Hee;Yang, Deok-Cho
    • Journal of Plant Biotechnology
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    • v.30 no.1
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    • pp.65-71
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    • 2003
  • This research aims the production of anti-tumor substances through in vitro culture of hairy roots transformed by Agrobacterium rhizogenes in Artemisia sylvatica MAX and the effect of culture conditions on optimum growth of hairy roots. We investigated the optimum medium, pH, carbon source, sucrose, light, Fe and polyamine conditions of various lines of hairy roots (NK3, NK4, YX. NK3-10) induced from Artemisia sylvatica to increase the optimum growth of hairy roots. MS medium was the best for optimum growth of hairy root clone, NK3-S10. The optimum culture period was 4 weeks for NK3-S10. The optimum sucrose concentration was 3.5%. The optimum concentration of FeSO$_4$, spermine and spermidine was 0.1 mM, 10 mM and 100 mM, respectively.

Effects of Temperature, Relative Humidity, pH and Triazole Fungicides on Sporulation anc Conidial Germination of Uncinula necator (포도 흰가루병균(Uncinula necator)의 분생포자 형성과 발아에 미치는 온도, 습도, pH 및 Trizole 살균제의 영향)

  • Oh, Jeung-Haing
    • Korean Journal Plant Pathology
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    • v.13 no.4
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    • pp.210-214
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    • 1997
  • The experiment was conducted to obtain basic informations on the effects of key environments and fungicides on the sporulation, conidial germination and hitial growth of the hyphae of grape powdery mildew fungus Uncinula necator. Maximum sporulation occurred at RH 75~96% in vitro adiusted with sulfuric acid solution. Conidial germination and initial growth of the hyphae were better at 5% water agar than distilled water, and best at $26^{\circ}C$ and pH 5.0 of the substrates. Germination occurred equally well at light intensity of below 100 lux or dark condition, which was better at water agar supplemented with leaf extract 30% than pure water agar. The water agar supplemented with triazole fungicides reduced conidial germinations and initial growth of the hyphae signifcantly, in proportion to the increase in concentration of the fungicides, but the maguitude of reduction depended on the fungicides. Particularly in myclobutanil, reduction rate was very low as increased in concentration.

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