• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권2호
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• pp.103-113
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• 2002

Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. Distraction osteogenesis is clinically applied as a new treatment modality of mandibular hypoplasia or bony defect area in maxillofacial area by many studies of distraction devices and method. But, disadvantages of distraction osteogenesis shows unfavorably long consolidation period and relapse tendency. Therefore, this experiment was designed to investigate the effectiveness of combined application of distraction and compression force for improving of bone quality and shortening of treatment period during distraction osteogenesis. Twenty-five Sprague-Dawley rats with $300{\sim}350gm$ were used. These were divided into two group as distraction group and combination group. The distraction group was added with conventional method during distraction osteogenesis, but the combination group was applied with compression force in the consolidation period. The rats were sacrificed for gross finding, radiographic and histologic findings at 3, 6 weeks after distraction. The results were as follow: 1. On radiographic finding, all combination of distraction and compression force group appeared more radiopacity than distraction group both at 3 weeks and 6 weeks after distraction group. 2. On histologic finding, the formation of mature lamellar bone were showed increasingly in combined group at 6weeks after distraction group. From this study, we may suggest that compression force application in consolidation period during distraction osteogenesis can be useful method to improve bone quality and to shorten the treatment period. But more experimental and clinical studies is necessitated on ideal application timing and method of compression force application during distraction osteogenesis.

• 한국세라믹학회지
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• 제32권7호
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• pp.817-824
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• 1995

TiB2 was simultaneously synthesized and densified with concurrent self-propagating high-temperature synthesis and direct contact-heating by electrcial power input and pressure. Density of TiB2 synthesized by self-propagating high-temperature synthesis and consolidated simultaneously by direct contact-heating and pressure was maximum 80% of the theoretical density (4.52g/㎤). Temperature profile was analyzed by solving heat balance equation with numerical method (FTCS method). The temperature of the sample was sufficiently raised to that temperature sufficient to be densified. It was ascertained that the density of the SHS synthesized TiB2 is exponentially proportinal to the input thermal energy per mass.

• 농촌계획
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• 제2권2호
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• pp.103-108
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• 1996

In rural planning, the cost estimation of project is a key factor for planning. Therefore, development of reliable cost estimation method is essential. Recently, new techniques are suggested for determination of project cost using historical cost data. In this study, a multiple-regression analysis was used to determine the cost of the farm land consolidation. The results demonstrated that multiple regression analysis using historical cost data can be applicable to project cost estimation.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2004년도 학술발표논문집
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• pp.74-74
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• 2004

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 가을 학술발표회 논문집
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• pp.111-120
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• 1998

• Smart Structures and Systems
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• 제7권4호
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• pp.275-287
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• 2011

The behaviors of saturated soils such as compressibility and permeability are distinguished by preconsolidation stress. Preconsolidation stress becomes an important design parameter in geotechnical structures. The goal of this study is to introduce a new method for the evaluation of preconsolidation stress based on the shear wave velocity at small strain, using Busan, Incheon, and Gwangyang clays in Korea. Standard consolidation tests are conducted by using an oedometer cell equipped with bender elements. The preconsolidation stresses estimated by shear wave velocity are compared with those evaluated by the Casagrande, constrained modulus, work, and logarithmic methods. The preconsolidation stresses estimated by the shear wave velocity produce very similar values to those evaluated by the Onitsuka method (one of the logarithmic methods), which yields an almost real preconsolidation stress. This study shows that the shear wave velocity method provides a reliable method for evaluating preconsolidation stress and can be used as a complementary method.

• Geomechanics and Engineering
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• 제28권2호
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• pp.157-169
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• 2022

Preloading of soft clays is a common ground stabilization method for improvement of compressibility and the undrained shear strength. The waiting period under preload is a primary design criterion controlling the degree of improvement obtained. Upon unloading the overconsolidation attained with respect to actual loads defines the long term performance. This paper presents a laboratory study for investigation of creep behavior of Famagusta Bay alluvial soft soil preloaded under various effective stresses for analysis of long term performance based on the degree of overconsolidation. Traditional one-dimensional consolidation tests as well as modified creep tests are performed on reconstituted soft specimens. Compressibility parameters are precisely backcalculated using one dimensional consolidation theory and the coefficient of creep is determined using the traditional Cassagrande method as well as two modified methods based on log cycles of time and the inflection of the creep curve. The test results indicated that the long term creep can be successfully predicted considering the proposed method. The creep coefficients derived as part of this method can also be related to the recompression index (recompression index, swelling index) considering the results of the testing method adopted in this study.

• 한국지반환경공학회 논문집
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• 제1권1호
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• pp.27-33
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• 2000

쇄석말뚝 공법은 다져진 자갈, 폐석, 쇄석 등을 이용하여 느슨한 사질지반이나 연약점성토 지반을 개량하는 공법으로 일반적으로 말뚝은 70%이상의 치환율로 실트질 점토에 시공되어 지지력을 증진시키는 공법이나 말뚝을 배수층으로 압밀에 의한 점성토의 지반의 강도 증가를 전제로 치환율을 30% 이하로 억제하는 저치환 공법의 효율에 관한 연구가 진행되고 있다. 본 연구에서는 쇄석말뚝의 치환율에 따른 단일 등가원주 모형 실험을 실시하여 쇄석말뚝이 연약지반의 압밀거동에 미치는 영향을 분석하였다. 실험결과 치환율의 증가에 따른 침하감소효과와 침하저감계수를 산정하였으며 복합지반의 압밀시간 단축을 확인하였다. 또한, 복합지반에 대한 이론식을 이용한 장기침하량 예측을 통해 보강지반의 침하억제 경향을 평가하고 베인전단시험을 통해 복합지반의 강도증가특성을 확인하였다.

• 한국중재학회지:중재연구
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• 제8권1호
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• pp.35-54
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• 1998

In recent years, there has been a significant increase in the number of large-scale projects involving construction, public works and the installation of industrial plants. These projects usually require the participation of a number of public and private entities and involve more than one contract. When disputes arising in connection with these projects are to be submitted to commercial arbitration, the parties often wish to have all disputes decided by one arbitral tribunal, in a single comprehensive proceeding. It has become apparent that the resolution of all major disputes which may arise in connection with such a project in a single comprehensive arbitration proceeding presents a number of advantages. The arbitral institution can provide for a multiparty arbitration proceeding only where all of the parties have agreed to it either at the time the disputes arise or at the time the parties enter into their various contractual arrangement. The discussion about multiparty arbitration centers on the question whether courts should have the power to order the consolidation of arbitration proceedings absent the consent of the parties. As the U.S. Supreme Court has repeatedly denied certiorari to cases presenting the consolidation-question, the conflict between the Court of Appeals' positions remains. The common method of selection in a bilaterial proceeding is the formula by which each party appoints one arbitrator and the two party-chosen arbitrators then mutually agree on a third, neutral arbitrator. This popular method poses, however, both a policy and practical problems In a 3-party-proceeding. It seems that the better solution is to have courts or arbitral institutions appoint all arbitrators for a multiparty proceeding. American courts have employed a variety of methods to appoint arbitrators for multiparty disputes in cases in which the parties had not provided for or could not agree upon a method themselves.

• 한국지반공학회논문집
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• 제29권3호
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• pp.5-13
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• 2013

압축지수는 점토의 압축특성을 나타내는 대표적인 물성치로 압밀시험으로 직접 결정하거나, 점토의 기본 물성으로부터 경험적 방법으로 추정한다. 그러나 자연점토의 압축지수는 지반 물성치뿐 아니라 퇴적상태에 영향을 받으므로 경험적 추정방법은 지역적 한계를 지닌다. 본 연구에서는 재성형점토의 압축특성을 이용하여 지반 물성치로부터 자연 점토의 압축지수를 추정하는 새로운 방법을 제안하였다. 부산점토의 압밀시험 결과를 통해 제안방법의 적합성을 검증하였으며, 오차원인을 분석하였다. 분석결과 제안된 방법은 경험적 추정방법보다 압축지수를 정확하게 추정하였다. 제안방법의 오차는 가정사항에 의해 발생하며, 추정오차는 $e_{cross}/e_0$와 명확한 반비례 관계를 나타냈다.