• Journal of Biosystems Engineering
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• v.29 no.3
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• pp.233-242
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• 2004

본 연구의 주요 목적은 자동 쌀 진공포장기의 3차원 기능적 가상시작기 모델을 개발하여 포장기의 구동시스템을 설계하고 개발하고자 하였다. 개발한 3차원 가상시작기는 주로 압축판부, 테이프부착부 및 진동판부로 구성되었다. 가상시작기의 민감도 분석을 수행하기 위해 제품포대의 두께변수를 이용하여 3차원 가상시작기를 파라미터화하였다 자동 진공포장기의 최대 처리능력 6포/분, 포대규격: 45cm${\times}$35cm을 충족하기 위해 각 주요부를 구동하는 모터 작동제어로직(motion control function)을 적절하게 설계하였다. 설계한 작동제어로직에 의하여 각 모터를 구동할 때 필요로 하는 적정 동력은 각각 100W, 25W 및 90W로 결정하였다. 연구결과를 요약하면 다음과 같다. 자동 진공포장기의 실제 시작기를 제조한 후 설계한 작동제어로직을 각 구동모터에 적용하여 시뮬레이션의 결과를 검증하였다. 개발한 3차원 가상시작기 모델을 시뮬레이션하여 선정한 모터들은 각 주요부를 원활하게 구동할 수 있었다. 제안한 작동제어로직은 주요부의 요구된 작동 시권스를 만족시켰으며 이때 자동진공포장기의 처리능력은 6.7 포/분이었다. 개발한 자동 쌀 진공포장기의 포장성공률은 92.6%이었다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.118-124
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• 2003

최근 농산물 시장의 개방에 따라 외국의 값싼 농산물이 지금 우리 유통시장에서 점차적으로 많이 판매되고 있다. 우리 농가의 생산소득을 높이기 위해서 경쟁력이 높은 고품질의 농산물이 생산되어야만 한다. 특히, 지금 우리나라 쌀 시장이 2004년에는 완전 개방되므로 이에 대비해서 쌀의 고품질화 및 특수미 개발로 우리 쌀의 국내소비량 및 국제 경쟁력을 높여야 한다 최근에 국내에서 여러 가지 특수미가 유통 및 판매되고 있는데 예를 들면, 배아미, 영양강화미, 발아현미, 무세미, 기능성 쌀 등을 들 수 있다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.259-266
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• 2003

2004년 쌀 시장개방을 대비하고 갈수록 높은 소비자의 구미요구에 맞은 고품질 쌀을 생산하기 위하여 특수미 및 영양미의 생산이 시급하다. 더 나아가 우리 농가의 생산소득을 높이기 위해서 경쟁력이 강한 고품질의 농산물이 반드시 개발되어야 한다. 최근에 국내에서 여러 가지 특수미가 유통 및 판매되고 있다. 예를 들자면, 배아미, 발아현미, 무세척미, 기능성 쌀 등을 들 수 있겠다. (중략)

• Journal of Biosystems Engineering
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• v.29 no.2
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• pp.131-140
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• 2004

본 연구에서는 배아미, 현미, 가능성쌀들 및 진공을 요하는 식품의 품질을 보존하기 위해서 연속식 자동진공포장기를 국내 최초로 개발하였다. 배아미의 진공포장 성공률은 92.6%이었고, 실패율 7.4%에서 진공포장기 자체에서 불완전 테이핑의 밀봉작업으로 진공이 서서히 풀리는 경우가 5.5%, 그리고 진공하기 전 자동비닐포장기에서 포장시 봉지 윗부분 밀봉이 불완전해 1.9%가 진공이 풀렸다. 이에 개발한 자동진공포장기의 진공포장성공률은 약 94.5%수준이었다. 진공포장기로 진공시간에 따른 진공압력을 측정하였고, 배아미 2, 3, 5 kg를 진공포장하는데 소요되는 시간은 각각 6, 8, 11초이었다. 진공포장으로 처리한 배아미와 진공포장 처리하지 않은 배아미를 각각 3재월간 저장실험하여 백도, 함수율, 과산화물가, 산가를 저장기간별로 분석하였다. 그 결과, 백도는 진공처리가 2 감소, 비처리가 4 감소하였고, 함수율은 진공처리가 0.8%감소, 비처리가 1.3%감소, 과산화물가는 진공처리가 최대 1.89 meq/kg까지 서서히 증가하였고, 비처리가 3.45 meq/kg까지 급속히 증가하였다가 서서히 감소하였다. 산가 역시 진공처리가 최대 0.71 mg/g까지 서서히 증가하였고, 비처리의 경우는 0.98 mg/g까지 급속히 증가하였다. 그리고 현미의 진공포장에서도 산가 및 과산화물가 변화가 배아미 경우와 비슷하였다. 또한 진공포장 제품에 인위적으로 쌀벌레들을 넣은 경우 15일 지나면 산소부족으로 모두 사멸하였다. 따라서 개발한 진공포장기로 진공포장한 경우 배아미 및 현미의 품질을 잘 보존할 수 있었다.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.399-408
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• 2002

The sweet persimmons are producted 227,394 tons per year in Korea. They are preserved at cold storage after wrapping them in packing vinyl to maintain quality. Using conventional handwork, a skillful worker could probably produce only 1,000 packings a day. Hiring many skilled-labors to wrap sweet persimmons in packing vinyl seems to be difficult because of the recent rural crisis. Therefore, it was necessary to be developed for the automated ordering and packing unit that is convenient and laborsaving. This study were summarized as follows : Success rates of 99%, 100%, and 88% were observed for ordering parts, sealing and cutting films, and sealing films in the inlet part, respectively. The time required per 1 cycle was 16 seconds and the developed unit performed 225 cycles an hour. The unit showed an ability of 1,125 pieces per hour. Therefore, the productivity was 10 times greater than that of skillful handwork.

• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.15-21
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• 2016

Nowadays, some studies have been performed for rockbolt method widely used in Korea. To make large slopes, tunnels or rock structures stable, supporting systems, such as anchor bolt, rock bolt which are developed recently, are commonly used. In this study, laboratory pullout tests were carried out to compare the characteristics of rock bolt that is most widely used with ones of rock bolt by newly developed circular model testers. Re-pullout test for the rock bolt in which loading and unloading cycles are repeated several times showed that the maximum pullout load is almost constant irrespective of the number of loading cycles, which may be due to no failure between rock bolt and filler that is filled with soils and concrete as a substitute. A development of rock bolt fillers as supporters using to protect people in tunnels and slopes is reviewed as a probable man-made hazard after excavation works. The functions of the grouted rock bolts associated with reinforcement effects also should be assessed in this study, which develop the sealing apparatus preventing from overflowing mortar out of a rock bolt hole for securing safety in the tunnel and slopes in order to secure stability named the sealing packer.

• Journal of Fashion Business
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• v.6 no.4
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• pp.46-61
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• 2002

The purpose of this study was to analyze critical needs and demands for the multifunctional traveler's jacket and to develop design prototypes based on the findings from the analysis. A self-report questionnaire with the stimuli was applied. Total 163 travelers were purposively sampled for the survey and the data were analyzed quantitatively as well as qualitatively. The results were as follows: 1. The respondents were divided into three groups - "digital-functionality-needs group", "non-digitalfunctionality-needs group", "no-need group", according to their preference and needs for the multifunctional traveler's jacket. 2. The three groups were analyzed (1) to have meaningful differences in experiencing inconvenience in their traveling, (2) to have statistically significant differences in their needs for the multifunctional traveler's jacket, (3) while some imperative consensus in their needs were found in part. 3. Based on the findings of the analysis mentioned above, three design prototypes were developed and visualized with conclusion.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.517-532
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• 2021

Safe geological disposal of spent nuclear fuel (SNF) requires knowledge of the deep hydrochemical characteristics of the repository site. Here, we conducted a set of deep hydrochemical investigations using a 750-m borehole drilled in a model granite system in Wonju, South Korea. A closed investigation system consisting of a double-packer, Waterra pump, flow cell, and water-quality measurement unit was used for in situ water quality measurements and subsequent groundwater sampling. We managed the drilling water labeled with a fluorescein dye using a recycling system that reuses the water discharged from the borehole. We selected the test depths based on the dye concentrations, outflow water quality parameters, borehole logging, and visual inspection of the rock cores. The groundwater pumped up to the surface flowed into the flow cell, where the in situ water quality parameters were measured, and it was then collected for further laboratory measurements. Atmospheric contact was minimized during the entire process. Before hydrochemical measurements and sample collection, pumping was performed to purge the remnant drilling water. This study on a model borehole can serve as a reference for the future development of deep hydrochemical investigation procedures and techniques for siting processes of SNF repositories.

• Journal of the Korean Geotechnical Society
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• v.33 no.7
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• pp.5-16
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• 2017

Soil nailing is the most general method to reinforce the slope by taking pullout and shear resistance force of the nail for stabilizing the slope. Domestic soil nailing design method considers only pullout resistance and does not consider the shear resistance sufficiently. In case of nail, the effect of tensile stress is dominant, but it is desirable to design by considering shear stress as well as tensile stress in case of slope where circle failures occur. Recently, studies on the shear resistance effect of nails have been carried out in the geotechnical field. However, many researches on the shear reinforcement effect of soil nailing have not been conducted until now. Most of the studies are about increasing pullout resistance by improving material, shape and construction method of nail. Therefore, it is necessary to the study on shear resistance of soil nailing and development of new methods to increase the shear force. In this study, large shear test and limit equilibrium analysis have been performed for a new soil nailing method to increase the shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar. The study results showed that shear resistance of protrusion type soil nailing increased compared to soil nailing and it is more effective when applied to the ground with large strength parameters.

• The Journal of Engineering Geology
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• v.9 no.3
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• pp.187-206
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• 1999

A computer program to numerically predict the permeability tensor of fractured rocks is developed using information on discontinuities which Borehole Televiewer and Borehole Image Processing System (BIPS) provide. It uses orientation and thickness of a large number of discontinuities as input data, and calculates relative values of the 9 elements consisting of the permeability tensor by the formulation based on the EPM model, which regards a fractured rock as a homogeneous, anisotropic porous medium. In order to assess feasibility of the program on field sites, the numerically calculated tensor was obtained using BIPS logs and compared to the results of pumping test conducted in the boreholes of the study area. The degree of horizontal anisotropy and the direction of maximum horizontal permeability are 2.8 and $N77^{\circ}CE$, respectively, determined from the pumping test data, while 3.0 and $N63^{\circ}CE$ from the numerical analysis by the developed program. Disagreement between two analyses, especially for the principal direction of anisotropy, seems to be caused by problems in analyzing the pumping test data, in applicability of the EPM model and the cubic law, and in simplified relationship between the crack size and aperture. Aside from these problems, consideration of hydraulic parameters characterizing roughness of cracks and infilling materials seems to be required to improve feasibility of the proposed program. Three-dimensional assessment of its feasibility on field sites can be accomplished by conducting a series of cross-hole packer tests consisting of an injecting well and a monitoring well at close distance.