• 한국전산구조공학회논문집
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• 제17권4호
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• pp.451-458
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• 2004

본 연구는 동결토의 동결심도 및 매설된 파이프라인의 온도분포를 예측하기 위하여 유효열용량 개념 반영한 수치해석 모델의 개발에 초점이 맞추어져 있다. 이를 위하여 저자는 사용코드인 ANAQUS를 활용하여 파이프라인이 매설된 폐쇄형 시스템의 화강 동결토에 대하여 비정상 열전달 수치해석을 수행하였다. 제안된 수치해석 모델은 Frozen Fringe에서 간극수의 상변화 효과가 반영되었다. 제안된 수치해석 모델과 실내 실험으로부터 얻어진 결과들을 비교함으로써 유효열용량 모델의 적용성을 검증하였다.

• 한국임상수의학회지
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• 제9권2호
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• pp.373-390
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• 1992

To assay the fertilizing capacity of domestic animal spermatozoa by hamster test, semen were collected from 13 boars(Duroc. Landrace and Yorkshire) which had been proved to be fertile in the past. then, were preserved in BWW medium or in raw state at 18$^{\circ}C$ or at room temperature. The preserved semen were given each different treatment according to the experimental design and coincubated with zona-free hamster ova for 5 hours. The ova were stained by lacmoid and examined under phase contrast microscope to investigate the rates of ova bound with sperm(sperm binding). ova penetrated by sperm(penetration) and formation of a male pronucleus(pronucleus formation) and also numbers of both bound and penetrated sperm per ovum. Between BWW and TBM medium for boar sperm. no difference in the results of hamster test was obtained. The boar spermatozoa in BWW medium, BWW with caffeine, BWW with heparin, and BWW with both caffeine and heparin showed no difference in the results of hamster test. The boar spermatozoa in BWW medium containing both calcium and RSA showed considerably higher rates of sperm binding, penetration and pronucleus formation as well as higher numbers of both bound and penetrated sperm than those not containing calcium with or without BSA( p<0.01) and also the same results higher than that containing calcium without BSA( p< 0.05). The boar spermatozoa irradiated by X-ray(70 KVP, 20mA) for 3 seconds. then, maintained at 18$^{\circ}C$ for 18 hours showed considerably lower rate of sperm binding than all the other groups including the control and X-ray groups irradiated by smaller dose or maintained for shorter period(p<0.01), and also showed lower number of bound sperm than the other groups(p<0.01, p<0.05). All the control groups of both raw and diluted sperm in BWM medium showed higher rates of sperm binding, penetration and pronucleus formation as well as higher number of penetrated sperm than all the X-ray groups irradiated for 3 seconds(70KVP, 20mA) and maintained for either 3 or 18 hours (p<0.01, p<0.05). At the same time the control groups of diluted sperm showed considerably higher rates of sperm penetration and pronucleus formation than the control group of raw sperm( p<0.01). These results indicates that fertile boar sperm showed considerably lower rates In the results of hamster test, when incubated in the medium without calcium and irradiated by X-ray than when incubated in the medium with calcium and not irradiated by X-ray, respectively, to prove consequently that hamster test would be of great value in assaying the fertilizing capacity of boar spermatozoa.

• 한국토양비료학회지
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• 제45권1호
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• pp.1-8
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• 2012

The thermal properties including volumetric heat capacity, thermal conductivity, thermal diffusivity, and diurnal and annual damping depths of 10 representative soil series of Korea were calculated using some measurable soil parameters based on the Taxonomical Classification of Korean Soils. The heat capacity of soils demonstrated a linear function of water content and ranged from 0.2 to $0.8cal\;cm^{-3}^{\circ}C^{-1}$ for dry and saturated medium-textured soil, respectively. A small increase in water content of the dry soils caused a sharp increase in thermal conductivity. Upon further increases in water content, the conductivity increased ever more gradually and reached to a maximum value at saturation. The transition from low to high thermal conductivity occurred at low water content in the soils with coarse texture, and at high water content in the other textures. Thermal conductivity ranged between $0.37{\times}10^{-3}cal\;cm^{-1}s^{-1}^{\circ}C^{-1}$ for dry (medium-textured) soil and $4.01{\times}10^{-3}cal\;cm^{-1}s^{-1}^{\circ}C^{-1}$ for saturated (medium/coarse-textured) soil. The thermal diffusivity initially increased rapidly with small increases in water content of the soils, and then decreased upon further increases in the soil-water content. Even in an extreme soil with the highest diffusivity value ($1.1{\times}10^{-2}cm^2s^{-1}$), the daily temperature variation did not penetrate below 70 cm soil depth and the yearly variation not below 13.4 m as four times of damping depths.

• 융합정보논문지
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• 제9권7호
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• pp.67-77
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• 2019

많은 중소기업이 Smart Factory를 구축할 때 기업 내 외부의 환경변화나 구성원들의 역량 등 기업이 처해있는 상황에 대한 충분한 고려 없이 구축하고 있다. 그래서 구축 후 활용도와 효과도 낮다. 본 연구는 '중소기업의 환경요인과 흡수역량을 통한 Smart Factory 구축'을 실증연구를 통하여 검증해 보는 것이다. 설문은 Smart Factory를 구축한 중소기업에서 관련 업무를 하는 인원에게 받았다. 연구결과는, 첫째, 기업 내 외부의 환경요인은 기업 내부의 흡수역량에 긍정적인 영향을 미쳤다. 둘째, 기업 내부의 흡수역량은 Smart Factory 구축에 긍정적인 영향을 미쳤다. 위의 입증을 통해서 중소기업에서 Smart Factory를 구축할 때 기업의 내 외부 환경요인과 흡수역량을 바탕으로 Smart Factory 핵심영역을 구축하면 효과적이라는 것이 입증되었다. 향후는 Smart Factory 구축성과의 연구를 하고자 한다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.209-216
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• 1997

The seismic performance of R/C frame structure designed for gravity load investigated in this paper. The investigation shows a satisfactory seismic performance against moderate earthquakes but column sway failure mechanism against severe earthquakes. Capacity design method is employed to redesign the R/C frame to improve seismic performance. This study provides an insight an insight into seismic upgrading methodology for medium rise R/C frame structures designed gravity load.

• 한국자원식물학회지
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• 제19권2호
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• pp.265-272
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• 2006

본 연구는 포자체 배양을 통하여 참쇠고비의 효율적인 번식방법을 구하고자 수행되었다. 배양절편의 기원(근경, 엽병, 엽신)과 절편의 균질화가 신초 계생에 미치는 영향을 조사한 결과, 오직 근경 조직에서만 기관발생능력이 관찰되었고, 식물체 재생은 배양재료를 균질화함으로써 더욱 촉진되었다. MS배지의 무기물 농도를 2배로 첨가한 배지에서 신초의 증식과 생장이 활발히 이루어졌다. 신초 재생에 적합한 배지의 질소함량은 MS배지의 1/2배 수준 이었고, 적정 sucrose농도는 1%였다. 또한 배지에 $NaH_2PO_4$를 첨가함으로써 재생된 식물체의 생육이 전반적으로 촉진되었다. 근경절편의 기관형성능력은 kinetin과 IBA를 혼용 처리함으로써 촉진되었으며, $0.1\sim0.2%$의 활성탄과 생장조절물질을 혼용 처리한 결과, 다수의 싹이 뭉친 듯이 보이는 primordia 형태의 발달이 억제되었고, 포자체의 정상적인 형태형성이 향상되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.225-229
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• 2009

International construction market has been open to other countries, and it derives the development of our overseas construction industry quantitatively as well as qualitatively. Until now, the major companies have an absolute majority in the overseas construction market, and the small and medium enterprises have had difficulty to get a leadership in the international construction market because of the lack of the technical expertise and the capital strength. Especially in the Middle East Asia, our construction companies has touched off a boom, so our market share also has grown, which derived from the up toward ratchet oil prices and a worldwide boom in real estate development. The small and medium enterprise minority have recognition that the overseas construction market is the major company's native territory. But Data from the existing researches and many statistics indicate the most companies tend to underestimate the capacity and international competitiveness of the small and medium enterprises. As a matter of fact, hundreds of small and medium enterprise cut a conspicuous figure in overseas market. Consequently, it is indispensable to overcome the international financial crisis by revitalizing our overseas construction industry which obtains excellent results in international market. this study suggested the ways to expand overseas bonding capacity of Korean financial institution. This study proposed the Korean government to allow Construction Guarantee (former Korea Construction Financial Cooperative) to deal with foreign exchange so that Construction Guarantee will underwrite the overseas construction bond.

• Advances in Traditional Medicine
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• 제7권2호
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• pp.162-170
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• 2007

Woodfordia fruticosa Kurz. (Lythraceae), commonly known as Dhayero, is used in the treatment of various ailments in Nepal. In this study, the antioxidant capacity of crude extract and different polarity fractions of Woodfordia fruticosa flowers were assayed for their scavenging abilities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide radicals, competitive ${\beta}$-carotene bleaching, reducing power, metal chelating ability and total phenolic content. Crude extract and polar fractions showed stronger antioxidant capacity and contained very high level of total phenolics. They exhibited strong DPPH radical scavenging, nitric oxide scavenging and reducing power, medium ${\beta}$-carotene bleaching and poor metal chelating capacity. Positive correlation obtained between total phenolic content and antioxidant capacity assays, indicated the contribution of phenolics toards antioxidant capacity.

• 한국경영과학회지
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• 제21권2호
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• pp.171-186
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• 1996

This paper comes from an observation that overemphasis on capacity utilization meausre, which is usual under capacity shortage, can seriously hurt the firm's profit and potential process improvement. We suggest a model that can be used in designing a coordination scheme for decentralized marketing and manufacturing activities. Using a price and time-sensitive demand and capacitated lotsizing model, we derive an effective communication medium betwen marketing and manufacturing. This Balance Indicator of process capacity and flexibility also implies that the increase in capacity availability and setup time reduction should be balanced by its market requirements. This is particularly important when a firm tries to improve its process capability by kaizen. Further, the model can be used to show the comparative performances of scheduling policies under capacity imbalnce. We show the shortening the scheduling cycle can improve the firm profit without changing the simple scheduling rule.

• 전자공학회논문지A
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• 제33A권7호
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• pp.76-91
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• 1996

In this paper, we proposed the new medium access control protocol for the virtual token bus netowrk. The network is applied to inter-processor communication network of large capacity digital switching system and digital mobile system with distributed control architecture. in the virtual token bus netowrk, the existing medium access control protocols hav ea switchove rtime overhead when traffic load is light or asymmetric according ot arbitration address of node that has message to send. The proposed protocol optimized average message delay using cyclic bus access chain to exclude switchover time of node that do not have message to send. Therefore it enhanced bus tuilization and average message delay that degrades the performance of real time communication netowrks. It showed that the proposed protocol is more enhacned than virtual token medium access control protocol and virtual token medium access control protocol iwth reservation through performance analysis.