• Journal of Biosystems Engineering
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• 제19권4호
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• pp.358-368
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• 1994

Major factors in reducing the stacking strength of corrugated fiberboard boxes in cold storage or transport conditions are high relative humidity, causing elevated moisture absorption by the boxes. The bottom boxes in a stack will deform to the critical deflection causing agricultural products damage there, and eventually additional deflection will cause box collapse and finally toppling of the stack. The study was conducted to determine the water absorption characteristics and the compressive strength of the corrugated fiberboard boxes being widely used in packaging agricultural products in Korea. The sample boxes for the study were selected from the regular slotted containers (RSC) types, and one was the box used in apple packaging (Box A), another one was the box used in pear packaging (Box B). The corrugated shipping containers were made from a large portion of recycled fibers in Korea, and comparing with Box B, Box A was fabricated from fiberboard which contained more percentage of old corrugated containers (OCC) imported from foreign countries than domestic waste paper. The results obtained from the study were summarized as follows ; 1. Equilibrium moisture content (EMC) of the sample boxes was established after about 20 hours, and the EMC by absorption was lower than that by desorption. The EMC increased with the increasing of relative humidity and with the decreasing of temperature, and the rate of increasing was much higher above the relative humidity of 50%. 2. The maximum compressive strength of Box A was about 100 kgf greater than that of Box B on the same enviromental conditions. The strength of the sample boxes decreased rapidly with the increasing of relative humidity. The effect of relative humidity on the strength was a little higher than that of temperature. 3. As the applied load was progressively increased and a level was reached, the vertical side panels ($L{\times}D$) deflected laterally inwards or outwards. The panels deflected laterally inwards at higher relative humidity. 4. The maximum compressive deflection ratio and the critical deflection ratio of the sample boxes were increased linearly with the increasing of relative hunidity, but trends for its ratios showed inconsistant response to temperature.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.2-5
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• 1996

Orissa is one of the major rice growing states of India. The state covers an area of 15.54 mha with 6.00mha cultivable holding is 1.46 ha. The power input is much below the national average of 0.87 hp/ha. Recently, the Government of Orissa has accorded equal status to Agriculture as given to the Industry with determination to increase the power input for agricultural production to2.54 hp/ha so as to obtain an average rice productivity of 3.0t/ha. Appropriate power units so as to be available with in the purchasing power of the small size farm owners in lieu of a pair of bullocks appear to be the right approach and is found to be in line with the highly successful Japanese and Korean model of small farm mechanization . The state needs 0.25m units of small tillers and tractors per year. The present population of tractors and power tillers in the state is about 11000nos. In India, two manufactures in collaboration with Japanese firms started manufacturing of power tiller sin 197 . The present production of power tillers in the country is about 1000 unit per year which is inadequate to meet the demands of all the stats. To meet the demands of the Orissa state, three Chinese model power tillers imported by local agencies are being supplied to the farmers during the past two years. Encouraged by the demand of power tillers in the state, three local manufacturing units located at Bhubanewar have come up with their own model of light weight power tillers(1.5 to 3.0 hp) during the past one year. These machine have been evaluated in the farms of the university and have been found to be promising . There is a target of supplying during 1996-97. The local manufacturers are in need of international collaboration for technical knowhow to manufacture these machine economically to meet the requirement of the farmers.

• 터널과지하공간
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• 제11권1호
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• pp.36-41
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• 2001

우리가 에너지원으로 사용하고 있는 연료는 40년이면 바닥이 난다는 게 일반적으로 알려진 사실이며 우리나라는 주거용에너지가 전체에너지 수요의 30∼40%를 차지하고 있는 실정이므로 주거용 에너지 절약의 한 방법으로서 지하공간의 사용을 검토해 봄직도 하다. 지하공간의 열 해석에는 그리드로 된 교점회로망을 구성하여 해석을 하게되는 데, 지금 시중에 나와있는 해석용 프로그램은 비싸고 큰 용량을 필요로 함으로 현장에서의 사용이 쉽지는 않다. 이 연구에서는 이러한 점에 착안하여, 교점회로망을 구성하여서 중심교점에 영향을 미치는 인접교점들의 열저항요소를 계산하여 행렬에 대입함으로써, 지중온도를 구하는 방법을 연구하여 실험현장의 실측치와 비교한 결과, 만족할 만한 결과를 얻었다. 따라서 이 방법을 적용하면, PC 에서도 값싼 계산용 프로그램 (C++, 포트란, 베이직 등)을 사용하여 지중온도를 쉽게 해석할 수 있을 것으로 생각된다.

• 한국가구학회지
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• 제16권2호
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• pp.59-65
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• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.

• 대한공간정보학회지
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• 제8권1호
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• pp.111-120
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• 2000

토지정보체계에서 기본도로 사용하는 지적도는 크게 도해지적과 수치지적으로 나뉘며, 수치지적의 경우 수치지적부상에 기록되어 있는 지번의 필지경계를 나타내는 절점의 위치좌표로 표시된다. 수치지적부의 변환은 문자형태의 자료로 입력된 필지의 절점좌표를 체계에서 사용할 수 있는 형태의 자료로 변환하여 사용하고 있다. 본 연구에서는 수치지적부의 절점좌표를 변환하는 과정에서 발생가능한 도형자료의 오차원인을 파악하고 이에 따른 정확도를 위치와 면적에 대하여 분석하고자 하였다. 이를 위하여 먼저 지형공간정보용 소프트웨어의 검증을 실시하여 좌표변환시 배정밀도를 사용하였을 때 정확도를 높일 수 있었다. 또한 위치에 대한 정확도 평가에서 절점에서 발생한 오차는 위상구조가 형성되는 과정에서 오차가 소멸되며, 다른 절점에는 영향을 주지 않는 것을 알 수 있었다. 면적에 대한 정확도 평가에서 절점의 위치오차로 인해 발생하는 면적오차는 허용면적(공차범위)에 들어 체계내에서 사용에 문제가 없음을 알 수 있었다.

• The Journal of Advanced Prosthodontics
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• 제12권2호
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• pp.67-74
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• 2020

PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.132-135
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• 2002

무선 통신 기술 분야에서 미래 지향적인 기술로 부각되고 있는 SDR(Software Defined Radio) 기술은 모든 하드웨어 중심적인 기존의 무선 통신 기기를 바꾸어 놓을 것으로 예상된다. SDR은 소프트웨어로 무선 장비의 사용 주파수, 변조 방식, 부가 서비스, 출력, 수신 감도 등 같은 무선 파라메타가 제어되는 기기이다. 전 세계적으로 이 기술에 의한 장비들이 개발, 보급되고 있는 이 시점에서 국내 도입에 있어서 단순히 기기의 수입을 통한 사용뿐만 아니라 앞으로 국내 생산업체의 기기 제조, 소프트웨어 개발, 제공 서비스 향상 등이 이루어 질 것이 전망된다. 그러나 향후 SDR의 보급과 사용자의 서비스 선택에 있어서 기기 간의 서비스 제공 방식의 경쟁적이고 독자적인 개발로 인해 경제적이고 효율적인 사용을 저해하는 요소가 불가피하게 발생될 것이 예상된다. 이에 따라 국내에서의 SDR 제공 서비스의 기술 표준을 마련하여 생산업체와 사용자의 편의를 도모하여야 할 것이다. 이에 따라 기본적으로 표준화되어야 할 요소들에 관하여 고찰하였다.

• 한국버섯학회지
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• 제3권4호
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• pp.159-171
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• 2005

The supply and demand of mushrooms has increased dramatically as the standard of living has increased and the nutritional and medical value of the mushrooms has been discovered. However, in meeting the demand, the profitability of the mushroom is being reduced. Even though there are many different types of and uses for mushrooms, the overall output production for the last ten years has consistently increased 5.9% per year, and for the last five years('00~'04) 5.2 % per year, and for the last 3 years('02~'04) 2.9% per year- the rate of increase has slowed. Looking at the standard gross income from mushroom production, it has increased 5.2% over the last nine years('95~'03), 1.6% over the last 4 years('00~'03), and 3.2% over the last 3 years('02~'04)-the annual gross income is decreasing. Even though the farmers are producing more mushrooms, the annual gross income is not increasing enough to keep up with the production, and therefore the profitability of mushrooms is decreasing. Since 2002, the constant increase of the output of edible mushrooms such as the Common Mushroom, Oyster Mushroom, King Oyster Mushroom and Winter Mushroom has resulted in a price declines. Before 2004, Korea mainly exported mushrooms, but after 2004 Korea mainly imported mushrooms. The mushroom industry of Korea is nearing the end of the stage of 'supplying domestic demand.' The stages are as follows: demand raised ${\rightarrow}$ supply domestic demand ${\rightarrow}$ export ${\rightarrow}$ country with developed mushroom industry. Therefore, we should have an efficient system to promote the exportation of mushrooms. Not only the exportation of mushroom itself but also the exportation of mushroom spawn, cultivation techniques and processing facilities should be our goal when we formulate the policy.

• 한국약용작물학회지
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• 제15권6호
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• pp.417-428
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• 2007

국내 유통 중인 한약재 대부분을 수입에 의존하고 있으나, 관리시설이 빈약하여 해충들에게 쉽게 노출될 수 있는 환경에 놓여 있다. 이 연구는 총 67과 134속 158종의 저장 한약재들을 대상으로 이들에서 발생하고 있는 저장물해충들을 조사하였다. 그 결과, Cassia 속의 육계, Juniperus 속의 자단향 그리고 Artemisia 속 애엽을 비롯한 44종의 한약재들에서는 곤충의 발생을 확인할 수 없었다. 한약재들에서 나타난 해충들의 발생빈도는 쌀머리대장 (A. advena) 12.3%, 권연벌레 (L. serricorne) 11.5%, 머리대장가는납작벌레 (O. surinamensis) 10.3%, 거짓쌀도둑거저리 (T. castaneum) 9.4%, 인삼벌레 (S. paniceum) 8.4% 그리고 화랑곡나방 (P. interpunctella) 7.9% 순이었다. 또한 이들 곤충들은 저장 중인 한약재들 중에서도 뿌리 또는 뿌리줄기 형태의 한약재들을 가장 선호한 것으로 보였다. 이 연구는 천연물 연구자들에게 곤충들이 발생하지 않았던 한약재들에 대한 기본 정보를 제공해줌으로써 향후 이들이 살충활성 또는 훈증활성물질을 탐색하는데 있어 이들 한약재들을 우선적으로 검토할 수 있는 유용한 자료로서 활용될 수 있을 것이다.

• 지역사회간호학회지
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• 제11권2호
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• pp.591-605
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• 2000

With the improvement of nutritive conditions and the influence of abundant information as well as various cultural aspects imported from foreign countries, puberty develops more rapidly in the body today. This study was conducted to suggest some ideas that are useful in planning sexual education programs in middle schools with ultimate aim being to promote sexual health. The subject of this survey consisted of 534 fifth graders from 4 schools in Hongchon. The major findings are summarized as follows: 1. The degree of sexual knowledge of adolescents showed a low average 31.00 and the degree of sexual attitude showed an average of 62.0. 2. With respect to demographic characteristics, there were statistically significant differences in sexual knowledge according to the following: living with parents (t=5.913. p=.015), father's education(F=3.213, p=.041), economic status (F=5.073 p= .007); and in sexual attitudes. there were statistically significant differences according to father's education (F=3.912. p = .002), and interest in the other sex (F=3.292, p=.038). 3. The level of sexual knowledge and sexual attitude of adolescents was correlated at significant levels(r= .354. p= .000). The findings of this study indicated that a variety of systematic sexual education programs suitable for each stage of adolescence should be developed along with family, society, and the country's higher concern and enlightenment.