• 대한치과보철학회지
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• 제42권4호
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• pp.356-372
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• 2004

Statement of problom: In the internal connection system the loading transfer mechanism within the inner surface of the implant and also the stress distribution occuring to the mandible can be changed according to the abutment form. Therefore it is thought to be imperative to study the difference of the stress distribution occuring at the mandible according to the abutment form. Purpose: The purpose of this study was to assess the loading distributing characteristics of 3 implant systems with internal connection under vertical and inclined loading using finite element analysis. Material and method: Three finite element models were designed according to the type of internal connection of ITI(model 1), Friadent(model 2), and Bicon(model 3) respectively. This study simulated loads of 200N in a vertical direction (A), a $15^{\circ}$ inward inclined direction (B), and a $30^{\circ}$ outward inclined direction (C). Result: The following results have been made based on this numeric simulations. 1. The greatest stress showed in the loading condition C of the inclined load with outside point from the centric cusp tip. 2. Without regard to the loading condition, the magnitudes of the stresses taken at the supporting bone, the implant fixture, and the abutment were greater in the order of model 2, model 1, and model 3. 3. Without regard to the loading condition, greater stress was concentrated at the cortical bone contacting the upper part of the implant fixture, and lower stress was taken at the cancellous bone. 4. The stress of the implant fixture was usually widely distributed along the inner surface of the implant fixture contacting the abutment post. 5. The stress distribution pattern of the abutment showed that the great stress was usually concentrated at the neck of the abutment and the abutment post, and the stress was also distributed toward the lower part of the abutment post in case of the loading condition B, C of the inclined load. 6. In case of the loading condition B, C of the inclined load, the maximum von Misess stress at the whole was taken at the implant fixture both in the model 1 and model 2, and at the abutment in the model 3. 7. The stress was inclined to be distributed from abutment post to fixture in case of the internal connection system. Conclusion: The internal connection system of the implant and the abutment connection methods, the stress-induced pattern at the supporting bone, the implant fixture, and the abutment according to the abutment connection form had differenence among them, and the stress distribution pattern usually had a widely distributed tendency along the inner surface of the implant fixture contacting the a butment post.

• 한국기계연구소 소보
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• 통권17호
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• pp.29-38
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• 1987

A mechanical linkage system to measure the operating temperature of the piston is developed and installed to the engine. Actual temperature distribution is measured for comparison with the numerical results. Heat transfer at the piston is analyzed using an FEM program. Thermal boundary condition of piston surface is determined by analytical and empirical methods. The temperature distribution and the thermal deformation are obtained by the FEM program.

• Geomechanics and Engineering
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• 제24권1호
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• pp.29-42
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• 2021

The utilization of buildings can be improved by extending them vertically. However, the added load of the extension might require building foundations to be underpinned; otherwise, the loads on the foundations might exceed their bearing capacity. In this study, a preloading method was presented aiming at transferring partial loads from existing piles to underpinning piles. A pneumatic-type model preloading device was developed and used to carry out centrifuge experiments to evaluate the load-displacement behavior of piles, the pile-soil interaction during preloading, and the additional loading caused by vertical extension. The results showed that the preloading devices effectively transfer load from existing piles to underpinning piles. In the additional loading test of group piles, the load-sharing ratio of a pile increased with its stiffness. The load-sharing ratio of a preloaded micropile was less than that of a non-preloaded micropile as a result of the reduction in axial stiffness caused by preloading before additional loading. Therefore, a slight reduction of the load-sharing capacity of an underpinning pile should be considered if the preloading method is applied. Further, two full scale preloading devices was developed. The devices preload underpinning piles and thereby produce reaction forces on a reaction frame to jack existing piles upward, thus transferring load from the existing piles to the underpinning piles. Specifically, screw-type and hydraulic-jack type devices were developed for the practical application of foundation underpinning during vertical extension, and their operability and load transfer effect verified via full-scale structural experiments.

• 멤브레인
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• 제14권4호
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• pp.289-297
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• 2004

유기물과 질소를 동시에 제거하기 위하여 연속회분식으로 운전한 MBR (membrane bioreactor)시스템에서 미생물농도와 슬러지 부하량이 막오염과 미생물 활성에 미치는 영향을 살펴보았다. 막오염은 MLSS (mixed liquor suspended solid) 농도 증가에 따라 조금씩 증가하는 경향을 보였고, 그 효과는 비포기 조건보다 포기 조건에는 좀더 두드러지게 나타났다. MLSS 농도는 막오염에 직접적인 커다란 영향을 주지는 않으나, 지나치게 높은 MLSS에서 유도되는 낮은 슬러지 부하에서는 막오염이 크게 증가하는 현상이 발견되었고, 이러한 조건에서는 포기에 의한 막 세척 효과도 크게 줄어들었다. 미생물의 개별 활성도는 슬러지 부하가 감소할수록 지속적으로 감소하는 경향을 나타내었다 반응조 전체 활성도 또한 17,000 mg/L 이상의 높은 MLSS로부터 유도되는 낮은 슬러지 부하율에서는 높은 미생물 농도에도 불구하고 오히려 감소했는데 이는 기질 부족으로 인한 경쟁으로 활성도가 떨어지고, 용액의 점성 증가로 인해 산소 전달율이 저하되었기 때문이다.

• Journal of Computational Design and Engineering
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• 제1권2호
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• pp.140-151
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• 2014

Storing, and the loading and unloading of materials at production sites in the manufacturing sector for mass production is a critical problem that affects various aspects: the layout of the factory, line-side space, logistics, workers' work paths and ease of work, automatic procurement of components, and transfer and supply. Traditionally, the nesting problem has been an issue to improve the efficiency of raw materials; further, research into mainly 2D optimization has progressed. Also, recently, research into the expanded usage of 3D models to implement packing optimization has been actively carried out. Nevertheless, packing algorithms using 3D models are not widely used in practice, due to the large decrease in efficiency, owing to the complexity and excessive computational time. In this paper, the problem of efficiently loading and unloading freeform 3D objects into a given container has been solved, by considering the 3D form, ease of loading and unloading, and packing density. For this reason, a Group Packing Approach for workers has been developed, by using analyzed truck packing work patterns and Group Technology, which is to enhance the efficiency of storage in the manufacturing sector. Also, an algorithm for 3D packing has been developed, and implemented in a commercial 3D CAD modeling system. The 3D packing method consists of a grouping algorithm, a sequencing algorithm, an orientating algorithm, and a loading algorithm. These algorithms concern the respective aspects: the packing order, orientation decisions of parts, collision checking among parts and processing, position decisions of parts, efficiency verification, and loading and unloading simulation. Storage optimization and examination of the ease of loading and unloading are possible, and various kinds of engineering analysis, such as work performance analysis, are facilitated through the intelligent 3D packing method developed in this paper, by using the results of the 3D model.

• 대한환경공학회지
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• 제28권7호
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• pp.770-775
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• 2006

휘발성 유기화합물 저감기술인 담체충진형 바이오필터법은 운전이 용이하고 처리비용이 낮다는 장점에도 불구하고, 낮은 운전성능과 막힘현상 등의 문제를 안고 있다. 이에 대한 대안으로 계면활성제로 형성된 거품을 사용해 VOCs의 물질전달율과 분해효율을 향상시킨 미생물 반응기(Bioactive Foam Reactor. BFR)가 제안되었다. 본 연구에서는 VOCs 저감기술로서 BFR의 적용가능성을 확인하기 위하여 styrene를 대상으로 실험실 규모 반응기 실험을 수행하였다. 체류시간 30초에서 미생물이 포함되지 않은 abiotic 실험과 biotic실험을 통해 BFR의 물질전달계수($K_La$)와 기질분해율(k) 값을 선정하였으며, 여타 산기방식의 생물반응조에 비해 BFR 시스템의 물질전달율이 월등히 높음을 확인하였다. 동적부하 변동실험 결과 BFR 시스템은 유입 styrene 농도가 급변하는 상황에서도 안정적인 처리효율을 나타내었다. 또한 BFR의 최대분해능은 109 $g/m^3/hr$으로 높게 나타나, 충진담체를 이용하는 전통적인 바이오필터의 대안 기술로 BFR 시스템을 적용할 수 있을 것으로 판단된다.

• The Journal of Korean Physical Therapy
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• 제17권1호
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• pp.108-122
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• 2005

The gait training strategy in very important things for central nervous system(CNS) injury patients. There are many method and strategy for regaining of the gait who had CNS injury. A human being has central pattern generator(CPG) is spinal CPG for locomotion. It is a neural network which make the cyclical patterns and rhythmical activities for walking. Sensory input from loading and hip position is essential for CPG stimulation that makes the central neural rhythm and pattern generating structure. From sensory input, the proprioceptive information facilitate proximal muscles that controlled in voluntarily from cortical level and visual and / or acoustical information facilitate distal muscles that controlled voluntarily from subcortical level. Gait training method can classify that is functional level and structural level. Functional level includ level surface gait, going up and down the stair. It is important to facilitate a guide tempo in order to activate the central pattern generators. During the functional test or functional activities, can point out the poor period in gait that have to be facilitate in structural level. There are many access methods with patient position and potentiality. The methods are using of rhythmic initiation, replication and combination of isotonic with standing position. Clinically using it on weight transfer onto the stance leg, loading response, loading response and pre-swing, terminal stance, up and downwards stairs.

• 산업공학
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• 제17권2호
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• pp.208-217
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• 2004

This paper deals with a process planning problem in the flexible assembly system (FAS). The problem is to assign assembly tasks to stations with limited working space and to determine assembly routing with the objective of minimizing transfer time of the products among stations, while satisfying precedence relations among the tasks and upper-bound workload constraints for each station. In the process planning of FAS, the optimality of assembly routing depends on tasks loading. The integration of tasks loading and assembly routing is therefore important for an efficient utilization of FAS. To solve the integrated problem at the same time, in this paper we propose a new method using an artificial intelligent search technique, named 2-leveled symbiotic evolutionary algorithm. Through computational experiments, the performance of the proposed algorithm is compared with those of a traditional evolutionary algorithm and a symbiotic evolutionary algorithm. The experimental results show that the proposed algorithm outperforms the algorithms compared.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1287-1294
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• 2006

A pile is compressed with settlements when loading and bearing capacity is altered along relative displacement of pile/soil on settlement and compression. Settlements of pile displaying limit skin friction is different from displaying tip resistance. Therefore, it is an error in traditional method that bearing capacity of pile is estimated from the sum of limit skin fraction and tip resistance. Accordingly, development of design method considering behavior of load-settlement is needed. In this study, we would like to establish the base for development of design method considering bearing capacity altering along displacement on settlement and compression. For this, we established system and substance of design method. And in order to establish relationship of load-settlement of pile on the type of soil, we analyzed and arranged existing database and pile loading test. On design method, settlement is assumed gradually on each capacity level being assumed gradually. Bearing capacity developing on the pile is obtained on each settlement level. Until the obtained bearing capacity will be equal to assumed capacity, this process is continued with increasing settlement. Load-settlement curve for soil classification is sketched in the process computing settlement on assumed capacity. This design method will be materialized by computation program.

• 디지털산업정보학회논문지
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• 제6권1호
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• pp.131-142
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• 2010

In this paper, we propose a web GPS based logistics vehicle control management system using MVC design patterns. The proposed system is designed by applying design patterns of object oriented modeling called mini-architecture to enhance reliability of software as well as promote stability of overall system design. In addition, we can get a position information by means of the GPS embedded in PDA and communicate between client and monitoring server using CDMA network so that the position of client can be identified directly by the map service. The system provides an moving object indexing technique which extends the existing TB-tree to manage and retrieve a transporting trajectory of logistics efficiently. Finally, with development of the logistics vehicle control service called WG-LOGICS system, we can verify the usefulness of our system which is able for monitoring a vehicle preparation, allocating registration, loading a burden, transfer path, and destination arrival in real world.