• 한국인터넷방송통신학회논문지
• /
• 제11권5호
• /
• pp.11-17
• /
• 2011

본 논문은 개체 관계 모델을 기반으로 하는 논리적 데이터베이스 설계도구인 ER_Modeler 개발에 관한 연구이다. ER_Modeler는 윈도우 상에서 개체 관계 다이어그램(Entity-Relationship Diagram: ERD)을 작성할 수 있는 그래픽 편집도구 기능과 생성된 ERD 정보로부터 논리적 데이터베이스 테이블을 정의하기 위해 데이터 정의어(Data Definition Language: DDL)를 자동 생성하는 기능을 제공한다. 또한 상업적으로 가장 많이 사용되고 있는 Erwin 제품과의 호환성을 제공하기 위해 XML을 이용하여 ERwin과의 Export/Import 기능도 제공해준다.

• 경영정보학연구
• /
• 제3권2호
• /
• pp.277-288
• /
• 2001

Of critical importance to the success of any e-commerce site are the two factors: rapid application development and quick response time. A three-tier architecture composed of presentation layer, business layer, and data access layer emerges to allow rapid changes in user interface, business logic, and database structures. Too often, such a logical three-tier architecture is considered as requiring a three-tier physical architecture: Web server, application server, and database server running on separate computers. Contrary to the common belief, a Web stress test reveals that the three-tier logical architecture implemented on a two-tier physical platform guarantees a quicker response time due to the reduction in cross-machine communications. This would lead business firms to economize their spending on e-commerce: increasing the number of physical servers to expedite transaction is not necessarily the best solution. Before selecting a particular hardware configuration, a Web stress test needs to be conducted to compare the relative merits of alternative physical architectures. Together with capacity planning, Web stress test emerges as a powerful tool to build robust, yet economical e-commerce sites.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2002년도 춘계학술대회 논문집
• /
• pp.30-33
• /
• 2002

There are several methods to implement the logical machine reasoning such as a frame theory and a production system of artificial intelligence. And these algorithms can explain the obtained result through the inference processes. However, emotional (KANSEI) patterns are not so easily implement. One of reason is that some emotional expression is the result of process from unconscious level to conscious level, and not easily identified the original unconscious causes. Therefore, a function of KANSEI database needs to structuralize unconscious level. Our approach is to develop the computerized counseling support system which can structuralize the unconscious brain functions from the view point of the psychology with focusing physiological and emotional responses. Especially, development of the algorithm that can form the network from unconscious to conscious using the image recollection is the application of the structured association technique (SAT). The developed system was implemented on the Web using CGI and emotional network database.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제2권2호
• /
• pp.82-102
• /
• 2008

Packet losses tend to occur during short error bursts separated by long periods of relatively error-free transmission. There is also a significant spatial correlation in loss among the receiver nodes in a multicast session. To recover packet transmission errors at the transport layer, tree-based protocols construct a logical tree for error recovery before data transmission is started. The current tree construction scheme does not scale well because it overloads the sender node. We propose a scalable recovery tree construction scheme considering these properties. Unlike the existing tree construction schemes, our scheme distributes some tasks normally handled by the sender node to specific nodes acting as repair node distributors. It also allows receiver nodes to adaptively re-select their repair node when they experience unacceptable error recovery delay. Simulation results show that our scheme constructs the logical tree with reduced message and time overhead. Our analysis also indicates that it provides fast error recovery, since it can reduce the number of additional retransmissions from its upstream repair nodes or sender node.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2009년도 춘계학술발표회 논문집
• /
• pp.29-34
• /
• 2009

Map update is required to provide up-to-date information. In update process, the most adequate generalization is to be applied to all scales of maps simultaneously. Most of existing maps are composed of 2D data and represented in 2D space. However, maps for next generation are to be generated with 3D spatial information including ortho-images and DEMs. Therefore, 3D generalization is necessary for 3D digital map update. This paper proposes methods for 3D generalization and correction for logical errors possibly accompanied with generalization.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 D
• /
• pp.2243-2245
• /
• 2002

This paper show Device Driver for RTOS-FT Systems. In this paper a definition of Device Driver is introduced which is used in RTOS-FT Systems. The structure of Device Driver is briefly divided into physical layer and logical layer. The specific characteristic of physical field and logical field which is discussed in this paper is suggested for the system which is satisfied with fault-tolerant theory.

• Journal of the Optical Society of Korea
• /
• 제12권2호
• /
• pp.69-78
• /
• 2008

EPONs are a low cost, high speed solution to the bottleneck problem of broadband access networks. To support point-to-point and shared LAN emulation, EPONs use the multi-point control protocol (MPCP), which uses logical link identification (LLID) forframe tagging and filtering between the OLT and ONUs. In this paper, ONU-based multicast or multiple shared LAN emulation for IPTV services is proposed using logical group identification (LGID). Using ONUbased VLAN services, EPONs can support separate and secure connections between providers and subscribers in a simple manner. Also, differentiated IPTV channel packages can be delivered through EPONs by implementing ONU-based VLAN and IGMP snooping mechanisms.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
• /
• pp.61-68
• /
• 1998

It has become important to evaluate the qualitive reliability and condition assessment of existing structural systems in order to establish a rational program for repair and maintenance. Since most of if existing structural system may suffer from defect corrosion and damage, it is necessary to account for their effects in fuzzy reliability analysis, In this paper, an attempt is made to develope a reliability analysis for damaged structural systems using failure possibility theory. Damage state is specified in terms of linguistic valiables using natural language information and numerical information, which are defined by fuzzy sets. Using a subjective condition index of failure possibility and information of the damage state is introduced into the calculation of failure probability. The subjective condition index of quantitative and qualitative analysis method is newly proposed based on the fuzzy set operations, namely logical product, drastic product, logical sum and drastic sum

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2002년도 춘계학술발표논문집 (상)
• /
• pp.691-694
• /
• 2002

현재 인터넷 환경은 다양한 멀티미디어 정보의 폭발적인 증가로 인해 정보의 효율적인 저장 및 관리, 가공을 위한 볼륨 관리자가 요구되고 있다. 따라서 본 논문은 대용량의 데이터 관리를 요구하는 SAN (Storage Area Network)환경에서 대용량 저장 장치 구성을 위한 LDP(Logical Disk Pool)를 설계하고 그 성능을 평가하였다. LDP는 여러 개의 물리적 디스크를 물리적 개념이 아닌 논리적 저장 공간의 개념을 사용하여 관리함으로써, 기존 물리 디스크의 크기 제한과 확장성 문제를 해결하여 SAN환경에 적합한 대용량 저장장치 구성을 가능하게 한다.

• ETRI Journal
• /
• 제27권6호
• /
• pp.725-732
• /
• 2005

The reconfiguration management scheme changes a logical topology in response to changing traffic patterns in the higher layer of a network or the congestion level on the logical topology. In this paper, we formulate a reconfiguration scheme with a shared buffer-constrained cost model based on required quality-of-service (QoS) constraints, reconfiguration penalty cost, and buffer gain cost through traffic aggregation. The proposed scheme maximizes the derived expected reward-cost function as well as guarantees the required flow's QoS. Simulation results show that our reconfiguration scheme significantly outperforms the conventional one, while the required physical resources are limited.