• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.411-414
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• 2002

A class of block designs for general combining ability comparisons within two groups of inbred lines in diallel crosses is given. Use is made of balanced block designs obtained by cyclically developing a single initial block.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.17-30
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• 2011

This study has analyzed the vegetation composition in the areas using different slope revetment techniques of riverbanks, in a way to improve the vegetation induction in the future considering the ecological aspects of the induction in Garaeyoul Village, Gangdong-gu, Seoul. The result of the vegetation distribution in each different slope revetment technique was analyzed, that the naturalized herb was dominant in the pole block accounting for 70.7%, while native herb was dominant in the lawn block occupying 48.5% and in the crib block occupying 55.7%. The vegetation coverage measured by different slope revetment techniques was highest in the crib block(average 97.5%), followed by the lawn block(average 95.3%) and pole block(average 27.9%). The vegetation base area was the most wide in the crib block and the most narrowest in the pole block. The result of community analysis in areas using different slope revetment techniques, dry herbs and vine herbs were dominated and the coverage was very poor in the pole block. In the lawn block, the barb was fragmented into narrow areas due to the blocks, which prevented the creation of large-scale plant communities. In the crib block, Miscanthus sacchariflorus, Fescue arundinacea and Aster pilosus, which also consisted of large-scale communities. Average dry weight was also measured by each slope revetment technique. The weight was heaviest in the crib block with $187.63g/m^2$, followed by the lawn block($137.65g/m^2$) and pole block($6.75g/m^2$). The soil moisture contents in the crib block and lawn block was 16.3% and 15.2%, respectively, while that of the pole block was 4.7%, which revealed the highly dry condition of the pole block soil. The analysis result of soil chemical property showed that there was little difference in soil texture, soile acidity(pH), and exchangeable ion content, however, the soil organic matter(OM) content and available $P_2O_5$ were highest in the pole block. In the future, in order to induce more vegetation into river banks and walls, a proper construction method should be applied so that the vegetation area can be expanded as much as possible, considering the safety of the banks.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.460-464
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• 2011

Poly(ether-block-amide)(PEBA, $PEBAX^{TM}$) resin is a thermoplastic elastomer combining linear chains of hard-rigid polyamide block interspaced soft-flexible polyether block. It was believed that the hard polyamide block provides the mechanical strength and permeation selectivity, whereas gas transport occurs primarily through the soft polyether block. The objective of this work was to investigate the gas permeation properties of carbon dioxide and methane for $PEBAX^{TM}$-1657 membrane and compare with those obtained for other grade of $PEBAX^{TM}$, $PEBAX^{TM}$-2533. And the organic/inorganic hybrid membranes were prepared using $PEBAX^{TM}$ and TEOS(tetraethoxysilane) by sol-gel process, and gas permeation properties were studied. $PEBAX^{TM}$-2533 membrane exhibited higher gas permeability coefficients than $PEBAX^{TM}$-1657 membrane. This was explained by the increase of chain mobility. The permeability coefficients for $PEBAX^{TM}$/TEOS hybrid membranes were higher than pure $PEBAX^{TM}$ membranes. This results were explained by the reduction of crystallinity of polyamide block by the introduction of TEOS. Ideal separation factor of hybrid membranes does not change much. This might be due to the increase of solubility selectivity.

• IE interfaces
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• v.22 no.1
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• pp.63-72
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• 2009

This paper considers a transporter scheduling problem under dynamic block transportation environment in shipbuilding. In dynamic situations, there exist the addition, cancellation or change of block transportation requirements, sudden breakdowns and maintenance of transporters. The transportation of the blocks in the shipyard has some distinct characteristics. Some blocks are available to be picked up at a specific time during the planning horizon while some other blocks need to be delivered before a specific time. These requirements cause two penalty times: 1) delay times incurred when a block is picked up after a required start time, and 2) tardy times incurred when a block shipment is completed after the required delivery time. The blocks are located at different areas in the shipyard and transported by transporters. The objective of this paper is to propose a heuristic algorithm based on a network flow model which minimize the weighted sum of empty transporter travel times, delay times, and tardy times. Also, a rolling-horizon scheduling method is proposed for dynamic block transportation environment. The performance of the proposed heuristic algorithms are evaluated through a simulation experiment.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.19-28
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• 2005

The purpose of this study was to improve the ankle joint to mechanical energy in Crouching start according to the backward block inclined angle(F, F(+1), F(+2)) increase. For purpose of this study the ankle joint was considered as a single hinge joint rotation about a transverse axis. A two-dimensional(sagittal plane) analysis was performed on data collected from 3 spriters(university student). During Crouching start, the ankle joint moment showed a similar patterns according to the backward block inclined angle increase. The peak values of ankle joint moment was plantar flexion approximately 80% throughout the contact phase for Crouching start. The absorbed and generated energy represented different values from the backward block inclined angle increase at ankle joint. On the backward block inclined angle F, subject A($55^{\circ}$) and C($50^{\circ}$) Produced energy generation more than other block inclined angles. On the backward block inclined angle F(+2), subject B($50^{\circ}$) showed largest energy generation.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.131-133
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• 1997

Number of elderly patients requiring nerve blocks have been increasing in recent years. We had two elderly patients who suffered stroke one day and three days after lumbar facet joint block and lumbar single epidural block respectively. Both patients due to their advanced age had potential risk factor to suffer one or more of the following; stroke, hypertension, and diabetes mellitus. Due to our experience with these patients, we suggested the following: (1) Nerve blocks should be reconsidered for elderly patient who posesses a potential risk factor to suffer a stroke. (2) Prior to invasive block administration of mild sedatives or analgesics may provide beneficial effects for patients with hypertension. (3) Adequately informed consent must be fully discussed time of consultation with patient scheduled for nerve block especially for elderly and risky patient.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.404-408
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• 2006

In this paper, connection strength between facing block and tie-bar was investigated through experimental study with varying in-fill material such as concrete, soil and crushed stone. Also, connection strength between anchor block and tie-bar was investigated with varying in-fill material. According to the experimental results, in case of using in-fill concrete, connection strength between facing block and tie-bar was larger than allowable tension load of tie-bar. Whereas in case of using in-fill soil or crushed stone, connection strength between facing block and tie-bar was less or similiar to allowable tension load of tie-bar. Connection strength between anchor block and tie-bar for which crushed stone was used as in-fill material, was larger than allowable tension load of tie-bar.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.77-85
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• 2013

The aim of this study is to investigate strength and water purification characteristics of effective microorganism-applied volcanic ash block using flexural strength test and water quality analysis. The specimens were prepared with volcanic ash from Mt. Baekdusan and Mt. Hallasan, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. Flexural strength degraded with increasing of the amount of volcanic ash, and increased with addition of metakaolin as a binder. Based on these results, the optimal ratio for fabricating volcanic ash-cement mixture block is determined as 3.5:1 with metakaolin. Furthermore, from water quality analysis on contaminated water, removal ability of effective microorganism-applied volcanic ash-cement mixture block and caged volcanic ash block against T-N, T-P and SS was highly evaluated because of adsorption due to the large specific surface area of volcanic ash. Hence, volcanic ash-cement mixture block and caged volcanic ash block possibly contribute to water purification.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.99-106
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• 2017

With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

• The Journal of Korean Society for Radiation Therapy
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• v.14 no.1
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• pp.95-99
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• 2002

I. 목적 : 결막 림프종 환자의 전자선 치료를 위해 Lens shielding block의 제작시 외부 의뢰 제작과 SMC 자체 제작의 장${\cdot}$단점을 비교해보고 제작 과정에 있어 업무의 효율성을 평가하고자 한다. II. 대상 및 방법: Lens shielding block의 제작시 외부의뢰제작과정과 자체 제작 과정을 비교하여 업무의 효율성, 인력의 변화 및 두방법의 장?단점을 분석하였다. 모의치료후 두 방법의 제작 시간을 비교하였으며, 재료의 차이점과 이용방법을 비교하여 개선된 사항을 알아보았다. III. 결과 : Lens shielding block의 자체 제작시 치료 시작시기는 모의치료 실시 후 7일에서 3일로 단축되어 업무의 효율성과 그에 따른 환자의 불편함이 줄어들게 되었다. 또한, 외부의뢰 제작 과정에서 실시되었던 치과와 치과 기공실에 의뢰하던 과정이 없어지고 과내 모의치료실과 공작실에서 작업하게 되어 모든 작업을 과내에서 일률적으로 실시할 수 있게 되었다. 또한, 모의치료를 실시하면서 실시간으로 shielding block을 수정 할 수 있어 정확성이 재고되었고, 반복되는 제작 작업으로 인해 제작 공정이 보편화되고, 손쉬어졌으며, 재료 활용의 효율성이 증대되었다. IV. 결론 : Lens shieiding block의 자체 제작으로 시간이 단축되어 업무의 효율성이 증대되었고 그에 따른 인력소모와 환자의 불편함이 줄어들게 되었으며, 제작자가 모의치료를 통해 바로 block의 오차를 수정할 수 있어 치료의 안정성 및 정확성이 높아졌으므로 결론적으로 의료의 질 개선과 서비스 향상이 이루어졌다.