• Geomechanics and Engineering
• /
• v.36 no.4
• /
• pp.329-341
• /
• 2024

Retaining structures are one of the most important elements in the stabilization of excavations and slopes in various engineering projects. Mechanically stabilized earth (MSE) walls are widely used as retaining structures due to their flexibility, easy and economical construction. These benefits are especially prominent for projects built on soft and weak foundation soils, which have relatively low resistance and high compressibility. For high retaining walls on weak foundations, conventional design methods are not cost-effective. Therefore, two alternative solutions for different foundation weakness are proposed in this research: optimized multi-tiered MSE walls and single tier wall with foundation improvement. The cost optimization considers both the construction components and the land price. The results show that the optimal solution depends on several factors, including the foundation strength and more importantly, the land price. For low land price, the optimized multi-tiered wall is more economical, while for high land price (urban areas), the foundation improvement is preferable. As the foundation strength decreases, the foundation improvement becomes inevitable.

• Journal of the Korean Geotechnical Society
• /
• v.17 no.3
• /
• pp.83-94
• /
• 2001

본 연구에서는 상.하단으로 구분된 2개의 동일한 보강토옹벽에 대해서 상호 이격거리에 따른 수치해석을 수행하여 전면벽체의 수평변위, 전면벽체 배면의 수평토압, 보강토체 배면의 수평토압 그리고 보강재의 최대인장력 분포 및 크기변화 양상 등 다단식 보강토옹벽의 거동을 살펴보았다. 또한, 하단 옹벽에 증가되는 응력을 산정하고자 중첩의 원리를 적용한 2:1 응력분포법을 제시하였다. 수치해석 결과 이격거리가 증가함에 따라 상단옹벽이 하단옹벽에 미치는 영향이 감소하였으며 하단 옹벽 높이의 두배 이상 이격시, 상호 거동은 독립옹벽으로 거동하였다. 하단 옹벽내 응력 산정방법에 있어서 NCMA의 방법이 가장 보수적인 결과를 보였으며 본 연구에서 제시한 2:1 응력분포법중 주동파괴면을 고려하지 않은 방법이 수치해석 결과와 가장 유사하게 나타났다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.1
• /
• pp.167-176
• /
• 2010

Managing the growing number of data generated through various processes requires the aid of Database Management System (DBMS) to efficiently handle the huge amount of data. These data can be inserted into database m real time or in batch, that come from multiple sources, including those that are coming from inside and outside of a network. The insertion of large amount of data is commonly done through specific bulk loading or insertion function supplied by each individual DBMS. In this paper, we analyze and evaluate on handling data bulk loading for heterogeneous systems that is organised as multi-tiered architecture and compare the result of DBMS bulk loader against program insertion from a software development perspective. We propose a hybrid solution using staging database that can be easily deployed for enhancing bulk loading performance compared to insertion by application.

• Journal of Arbitration Studies
• /
• v.12 no.2
• /
• pp.263-302
• /
• 2003

Since new Korean arbitration law was modeledafter UNCITRAL Model Law on International Commercial Arbitration Law, the judicial review on the arbitral award is at most limited to fundamental procedural justice. Thus, drafting valid arbitration clause is paramount important to enforce arbitral awards in the new legal environment. A losing party in arbitral process would often claim of the invalidity of arbitration agreement to challenge the arbitral award. Especially, the validity of arbitration clause in the construction contracts is often challenged in Korean courts. This is because the construction contracts usually include selective arbitration agreement in multi-tiered dispute resolution clause that is drafted ambiguous or uncertain. In this paper selective arbitration agreement means a clause in a contract that provides that party may choose arbitration or litigation to resolve disputes arising out of the concerned contract. On the hand multi-tiered dispute resolution clause means a clause in a contract that provides for distinct stages such as negotiation, mediation or arbitration. However, Korean courts are not in the same position on the validity of selective arbitration agreementin multi-tiered dispute resolution clause. Some courts in first instance recognized its validity on the ground that parties still intend to arbitrate in the contract despite the poor drafted arbitration clause. Other courts reject its validity on the ground that parties did not intend to resort to arbitration only with giving up their right to sue at courts to resolve their disputes by choosing selective arbitration agreement. Several cases are recently on pending at the Supreme Courts, which decision is expected to yield the court's position in uniform way. Having reviewed recent Korean courts' decisions on validity and applicability of arbitration agreement, this article suggests that courts are generally in favor of arbitration system It is also found that some courts' decisions narrowly interpreted the concerned stipulations in arbitration law despite they are in favorable position to the arbitration itself. However, most courts in major countries broadly interpret arbitration clause in favor of validity of selective arbitration agreement even if the arbitration clause is poorly drafted but parties are presume to intend to arbitrate. In conclusion it is desirable that selective arbitration agreement should be interpreted favorable to the validity of arbitration agreement. It is time for Korean courts to resolve this issue in the spirit of UNCITRAL model arbitration law which the new Korean arbitration law is based on.

• Journal of KIISE:Software and Applications
• /
• v.31 no.8
• /
• pp.969-979
• /
• 2004

Recently, large-scale enterprise information systems are commonly based on the multi-tiered middleware or frameworks to support such requirements as functional reuse, heterogeneous system resources, and multiple platforms. However, these multi-tiered or distributed multi-platform architecture incurs the interoperability issue of the components and metadata among the middleware. This paper introduces the Simple Object Application Framework (SOAF) which supports heterogeneous resources and platform-independent component-based development, with the abstract programming style of the object-oriented frameworks and the XML-SOAP based component persistence mechanism.

• The Mathematical Education
• /
• v.54 no.3
• /
• pp.283-298
• /
• 2015

This research is the case study of collaborative mentoring in the professional development of multi-tiered mathematics teacher community. We observed the procedures of mentoring, and contents of mentoring in PD program. For this purpose, we implemented PD program with participant unit composed of 3 or 4 teachers in the same school and total 25 teachers from 4 elementary schools and 4 high schools. Also there were 1 mentor and 1 sub-mentor to support each school. Observed mentoring processes were all recorded and the participants not only were interviewed several times but also wrote reflection notes after meetings. While mentoring PD program was implemented, mentor and mentee had joint responsibility about lessons implemented by mentee. Furthermore It showed possibility of change of teacher learning culture, learning culture of community. It means that teacher would improve their professionalism more effectively within teacher community instead of individual. 4 reflection contents was founded in collaborative mentring; 1)purpose of mathematics education, 2)motivation and connection between previous lecture and present lecture 3)lack of mathematical contents in lesson 4)discourse between teacher and students.

• Journal of Korea Multimedia Society
• /
• v.9 no.6
• /
• pp.742-749
• /
• 2006

In the network-based game where it uses the Internet infrastructure, the implementation is possible with the various methods. Such Applications are developed in the multi-tired architecture. There are many cases for the server to be separated from the hardware or the software. In this case, a lot of applications make the distributed process possible and are made as the multi-tiered architecture to develop the reusability of the existing software module. Especially, it is mostly general to separate for the case of a database server to a new tier. One of the important points of multi-tiered server side applications is security and because of this, it is difficult to share the related data about the design skill. Using design patterns, it gives help in reusing the existing written-code for the design of the game that needs a lot of money and time. Design Patterns are related to the software reuse. For the development of more efficient games, if well-defined design patterns are provided to the developers, then it would make more easy advanced game API and make possible the framework for the game development based on the API Through the analysis of the general network-based game currently servicing in the Internet, in this paper, we discuss how to implement a business logic tier using database system among the server side architectures. The main objective of this article is to show an efficient APIs(Application Programming Interfaces) design method which can be used to manage the data that must be saved to the database system among the packets that client/server have to be exchange.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.355-357
• /
• 2004

센서 네트워크는 계산 용량과 에너지가 제한적이라는 특성을 가지며 그 결과 시스템의 보안관련 요구를 만족시키기 위해 기존 네트워크의 방식을 적용할 수 없다. 본 논문에서는 센서 네트워크의 보안을 위하여 기존 다층화 된 보안구조에서 사용되는 키 분배 방식을 개선함으로써 에너지 소모를 크게 증가시키지 않으며 전체 네트워크의 신뢰도를 개선할 수 있는 방법을 제안한다. 랜덤 그래프의 성질을 이용한 키 분배 방식으로 이를 이용하여 비교적 낮은 에너지 소모와 개선된 신뢰성을 적절히 제공할 수 있다.

• New & Renewable Energy
• /
• v.1 no.3 s.3
• /
• pp.24-34
• /
• 2005

Ministry of Commerce, Industry [MOCIE] has taken it into consideration to introduce a Renewable Portfolio Standard (RPS) that is a purchase obligation program as an alternative plan to the FIT. We conducted a survey of renewable energy companies and experts to ask their opinions about renewable energy policy, the introduction of the RPS, and the scheme for aid of North Korea with renewable energy. Korean renewable energy companies show an impartial opinion about a FIT and a RPS system overall, although they tend to have distinctive opinions by technology each other. With respect to eligible resources for a RPS, the industries want to extend the scope of it as broad as possible. In addition, experts prefer the multi-tiered and energy production based RPS to the sing1e-tiered and installed capacity based RPS. We also conducted a surrey to find the best renewable energy sources. Wind, Geothermal, Solar-thermal, and Photovoltaic were selected to have the best potential capacities to support North Korea by renewable energy experts. However, these energy resources also have several problems to overcome in the aid of North Korea, and thus, the plans for solving them and for giving efficient support to North Korea in the area of Renewable Energy are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.9
• /
• pp.3034-3055
• /
• 2014

Wireless Sensor Networks have extensively been utilized for ambient data collection from simple linear structures to dense tiered deployments. Issues related to optimal resource allocation still persist for simplistic deployments including linear and hierarchical networks. In this work, we investigate the case of dimensioning parameters for linear and tiered wireless sensor network deployments with notion of providing extended lifetime and reliable data delivery over extensive infrastructures. We provide a single consolidated reference for selection of intrinsic sensor network parameters like number of required nodes for deployment over specified area, network operational lifetime, data aggregation requirements, energy dissipation concerns and communication channel related signal reliability. The dimensioning parameters have been analyzed in a pipeline monitoring scenario using ZigBee communication platform and subsequently referred with analytical models to ensure the dimensioning process is reflected in real world deployment with minimum resource consumption and best network connectivity. Concerns over data aggregation and routing delay minimization have been discussed with possible solutions. Finally, we propose a node placement strategy based on a dynamic programming model for achieving reliable received signals and consistent application in structural health monitoring with multi hop and long distance connectivity.