• Journal of Digital Contents Society
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• v.13 no.4
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• pp.525-530
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• 2012

Wireless sensor networks consist of resource constraint devices which typically send data measured by sensors attached to the end devices towards a coordinator. One of the best solution for wireless sensor networks is ZigBee, where it is wireless standard introduced for low power, low cost wireless communication with moderate data rates. In this paper, we present porting of Z-Stack and implementation of UART on the TI CC2530. We show that our implemented board works correctly in terms of transmitting and receiving data via serial port.

• Journal of Electrical Engineering and information Science
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• v.3 no.1
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• pp.1-7
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• 1998

High-Level synthesis of digital circuits calls for automatic translation of a behavioral description to a structural design entity represented in terms of components and connection. One of the critical steps in high-level synthesis is to determine a particular scheduling algorithm that will assign behavioral operations to control states. A new scheduling algorithm called Data Availability Scheduling (DAS) for high-level synthesis is presented. It can determine an appropriate scheduling algorithm and minimize the number of states required using data availability and dependency conditions extracted from the behavioral code, taking into account of states required using data availability and dependency conditions extracted from the behavioral code, taking into account resource constraint in each control state. The DAS algorithm is efficient because data availability conditions, and conditional and wait statements break the behavioral code into manageable pieces which are analyzed independently. The output is the number of states in a finite state machine and shows better results than those of previous algorithms.

• Proceedings of the Technology Innovation Conference
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• 2000.06a
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• pp.175-209
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• 2000

The performance of US economy in the last cecade is considered to be driven by the IT investment. However, the causal relationship has not been conclsive between IT investment and economic performance, which makes a decision in IT investment tricky. IT as a growth strategy is critical to the developing countries which experienced resource constraint. In case IT acts as a driving force in the new technology paradigm, the less investment in IT will continue to which the growth gap between countries. When IT dose not make a significant contribution to growth, heavy investment in IT means misallocations of resources. Therfore a decision on IT investment has critical implication in terms of growth strategy. Based on a growth accounting nethod, the current study is to analyse the contribution of IT

• IE interfaces
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• v.14 no.4
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• pp.348-355
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• 2001

This paper suggests a detailed design of APS(Advanced Planning & Scheduling) system using the DBR (Drum-Buffer-Rope) which is a finite capacity scheduling logic of TOC(Theory of Constraints). Our design is composed of four modules; Network, Buffer, Drum and Subordination. The Network module defines the Product Network which is built from BOM and routings. The Buffer module inserts the Buffers into the Product Network. The Drum module describes detail procedures to create Drum Schedule on the CCR(Capacity Constraint Resource). The Subordination module synchronizes all non-constraints to the constraints by determining the length of Rope. This design documented by ARIS.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.205-207
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• 2005

최근 수많은 정보를 통해서 증명 되듯이 비즈니스 프로세스 관리(Business Process Management, BPM)는 기업의 소프트웨어 시장의 가장 중요한 부분을 차지하고 있다. 비즈니스 프로세스 관리는 프로세스 전 라이프 사이클을 지원하고자 하는 개념으로 급변하는 경영 환경의 변화에서 기업의 경쟁력을 재고 하기위하여 필요로 되는 새로운 기업 컴퓨팅 패러다임이다. 비즈니스 프로세스 관리의 핵심적인 정보시스템 역할을 수행하는 워크플로우(Workflow)에서의 스케줄링은 정확한 업무 순서를 명세하기 위한 시간적인 제약들에 집중되어 있다. 워크플로우와 BPM과 같은 비즈니스 프로세스에서의 또 하나의 중요한 측면은 자원할당관리이다. 현재 대부분 다양한 자원들을 모델링하는데 초점을 맞추어 왔으며 자원들과 연관된 제약에서의 스케줄링에 대한 관심은 많지 않은 편이었다. 본 논문에서는 First Order Logic 기반의 CTR(Concurrent Transaction Logic)을 이용하여 각 비즈니스 프로세스 스케줄링을 위한 자원할당에 따른 제약들을 논리적인 모형으로 구체화하고, 모형에 필요한 변환 규칙을 소개하고자 한다.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.163-163
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• 2000

오늘날 기업환경은 고객의 요구에 대응하여 적시에 효율적으로 상품과 서비스를 공급하고 전체비용의 대부분을 차지하는 물류와 재고비용을 줄여 기업의 이윤을 극대화하는 것으로 변화하고 있다. 예전에 기업위주의 시장형성에서 고객위주로 시장이 변화하고 있는 것이다. 이에 따라 기업은 고객의 요구에 능동적으로 대응하기 위하여 리드타임의 단축이 필수적인 요소가 되어가고 있다. 이러한 기업환경에 변화에 따른 대안으로 나온 것이 실시간 제조와 공급사슬망관리(Supply Chain Management : SCM)이다. 본 연구는 실시간 제조를 지원하기 위하여 제조업체와 협력사간의 물류에 있어 Goldratt의 Drunm-Buffer-Rope 스케줄링을 이용하여 물류창고라는 Buffer를 두어 협력사중 재고의 부족현상이 일어날 경우에는 공급체인상의 능력제약자원(Capacity Constraint Resource: CCR)을 찾아 능력제약자원이 되는 협력사에 대하여 생산을 독촉하고 물류창고에서는 부족재고에 대한 불출을 개시하여 재고의 완충을 도모하고자 한다. 제조업체와 협력사간의 정보를 실시간 감시시스템(Real-Time Monitoring System : RTMS)를 응용하여 웹상에서 공유하며, 실시간 거래가 가능토록하는 공급사슬망 구축에 관한 연구와 이를 프로그램 구현을 통해 실제적으로 시험해 보고자 한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.402-408
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• 2002

Multicast technology allows the transmission of data from one source node to a selected group of destination nodes. Multicast routes typically use trees, called multicast routing trees, to minimize resource usage such as cost and bandwidth by sharing links. Moreover, the quality of service (QoS) is satisfied by distributing data along a path haying no more than a given number of arcs between the root node of a session and a terminal node of it in the routing tree. Thus, a multicast routing tree for a session can be represented as a hop constrained Steiner tree. In this paper, we consider the hop-constrained multicast route packing problem with bandwidth reservation. Given a set of multicast sessions, each of which has a hop limit constraint and a required bandwidth, the problem is to determine a set of multicast routing trees in an arc-capacitated network to minimize cost. We propose an integer programming formulation of the problem and an algorithm to solve it. An efficient column generation technique to solve the linear programming relaxation is proposed, and a modified cover inequality is used to strengthen the integer programming formulation.

• Proceedings of the IEEK Conference
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• summer
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• pp.395-399
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• 2004

We present modality conversion as an effective means for QoS management. We show that modality conversion, in combination with content scaling, would give a wider range of adaptation to support QoS at media level. Here, we consider modality conversion with respect to resource constraint and human factor. To represent modality conversion as well as content scaling, we present the overlapped content value (OCV) model that relates the content value of different modalities with resources. The specification of user preference on modality conversion is divided into qualitative and quantitative levels. The user preference is then integrated into the OCV model so that modality conversion correctly reflects the user's wishes. For the conversion of multiple contents, an optimization problem is formulated and solved by dynamic programming. The experiments show that the proposed approach is efficient to be applied in practice.

• Communications for Statistical Applications and Methods
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• v.12 no.2
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• pp.443-451
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• 2005

The studied in this paper is a new algorithm for searching the maximum likelihood estimate(MLE) in which probability density function is not explicitly expressed. Newton-Raphson's root-finding routine and a nonlinear numerical optimization algorithm with constraint (so-called feasible sequential quadratic programming) are used. This algorithm is applied to the Wakeby distribution which is importantly used in hydrology and water resource research for analysis of extreme rainfall. The performance comparison between maximum likelihood estimates and method of L-moment estimates (L-ME) is studied by Monte-carlo simulation. The recommended methods are L-ME for up to 300 observations and MLE for over the sample size, respectively. Methods for speeding up the algorithm and for computing variances of estimates are discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.65
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• pp.89-102
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• 2001

In this paper, the aircraft route scheduling consists of two steps; the pairing generation and the aircraft assignment. The pairing generation is heuristic approach how flights construct pairings from and to the main base. The aircraft resource assignment which is to establish a aircraft route schedule is constructed by constraint satisfaction problem technique. ILOG solver and schedule is used to solve this problem. In addition, a aircraft route reschedule process against departure-arrival delay or aircraft maintenance schedule change is added by partial constraints satisfaction problem technique. Also, Gantt chart made by ILOG views is used to show aircraft route schedule results more easily.