• Journal of the Korean Operations Research and Management Science Society
• /
• v.5 no.1
• /
• pp.31-38
• /
• 1980

The purpose of this paper is to exhibit existing replacement models and to develop new replacement models for managing equipments in large organizations, private or public. Some of the models in this paper are well known and in use, and some are not. All these models are classified, depending on main factors which play key roles on the models. One group is the models in which the economic factor plays a key role, and the other is those in which both the economic factor and the effectiveness factor play key roles.

• Proceedings of the Korean Society for Quality Management Conference
• /
• 2006.04a
• /
• pp.469-472
• /
• 2006

In this thesis, We analyzed success enterprise case which is well worked by knowledge management and is gained effect results. We searched key factor for success knowledge management and found problem which is able to happen when is introduced by success enterprise in knowledge management. We applied to in franchies real field with key factor found above results and experimented others real fields.

• Proceedings of the Safety Management and Science Conference
• /
• 2008.11a
• /
• pp.383-393
• /
• 2008

In this thesis, We analyzed success enterprise case which is well worked by knowledge and is gained effect results. We searched key factor for success knowledge management and found problem which is able to happen when is introduced by success enterprise in knowledge management. We applied to in franchise real field with key factor found above results and experimented others real fields.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.6
• /
• pp.159-166
• /
• 2007

Work delay is one of the facts that make the reliability of construction projects decrease. Therefore, it is important to classify and prioritize the delay factors. This research analyzed key delay factors in apartment house construction through survey. The results of analysis are as follows. (1) Insufficient work force is the key delay factor in structural and finish work. (2) Improper craft of worker is the key delay factor in electrical work. (3) Incompletion of proceeding work is the key delay factor in mechanical work.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.1599-1607
• /
• 2009

In order to deal with severe competition in the construction market of developing countries, large contractors must continually improve their own performance and operation. Performance measurement is the heart of ceaseless improvement in organizations. Key performance indicators (KPIs) play a key role in measuring project management performance (PMP) of large contractors in developing countries. The main objective of this paper is to identify KPIs, which can be used to measure PMP of contractors, and then analyze the underlying relationships of these KPIs in order to gain insight into PMP of large construction firms in Vietnam construction industry (VCI). Literature reviews and the pilot survey provided 30 KPIs. Fourteen KPIs, which have the mean values higher than 3.0, were considered as important KPIs through a questionnaire survey of 32 professionals. Factor analysis of these KPIs was employed to categorize them. The results of the survey revealed that top six KPIs are construction time and cost, owner satisfaction on services and products, and quality management and project team performance. Factor analysis uncovered that 14 top-ranked KPIs can be grouped under six categories, namely: (1) construction input management, (2) owner satisfaction, (3) cost and quality, (4) manpower management, (5) subcontractor performance and (6) equipment management. The findings of this research can be used as a guideline to measure PMP of contractors in Vietnam as well as in other developing countries. Since contractors from a country to the other country may have the same manner to manage construction projects, the results of this study may be useful not only to practitioners and researchers in Vietnam but also to participants in other developing countries.

• International conference on construction engineering and project management
• /
• 2013.01a
• /
• pp.14-20
• /
• 2013

Substantial research has been performed on the data standards and exchanges in the AEC/FM industry over the past several years. The growing popularity of BIM technology is based heavily upon a perception that the technology can facilitate the sharing and reuse of information during a project life-cycle. Although many researchers and practitioners are in agreement about the potential applicability and benefit of BIM in construction, it is still unclear why BIM is adopted, and what factors enhance implementation of BIM. Thus, BIM acceptance and use remains a central concern of BIM research and practice. Therefore, we propose the key factors affecting the acceptance of BIM in construction organizations using factor analysis. The key factors for BIM acceptance are identified through a literature review in TAM (Davis 1989) and related theories, and consolidated by interviews and pilot studies with professionals in construction industry. Based on the factors, a questionnaire was designed and sent out to construction organizations such as contractors, architects, and engineers in Korea. Total 148 completed questionnaires were retrieved. Using factor analysis, key factors were grouped into six dimensions. These findings will clarify what the highly prioritized factors are, and can also be used in an assessment tool for the performance of BIM utilization.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.2
• /
• pp.13-18
• /
• 2011

Security supports are a significant factor in mobile ad hoc networks. Especially in dynamic topologies, considering cluster, key management is essential to provide a secure system. Recently, Li-Liu proposed iD-based multiple key management scheme for cluster-based ad hoc networks. However, we found the security weakness of their scheme. In this paper, we analyze the security of Li-Liu's scheme and show that master secret key and fragment of the master secret key can be revealed to compromised CHs and nodes. Furthermore, we propose a solution to improve the scheme against disclosure of the share key and the master secret key even though system parameters are opened to compromised nodes and modify the Li-Liu's scheme fitted for a scalable networks. The improved IMKM scheme could be usefully applied in dynamic cluster-based MANETs such as the military battlefields, mobile marketplace and VANETs.

• Journal of Korean Society for Quality Management
• /
• v.31 no.1
• /
• pp.123-131
• /
• 2003

This paper considers a six sigma project for reducing the defects rate of the welding process in manufacturing firms. The project follows a disciplined process of five macro phases. define, measure, analyze, improve and control(DMAIC). The need of customers is used to identify critical to quality(CTQ) of project. And a process map is used to identify process input factors of CTQ. Four key process input factors are selected by using an input factor evaluation of teams; an interval of welding, an abrasion, an electric current and a moving freely. DOE is utilized for finding the optimal process conditions of the three key process input factors. Another one key input factor improved to welding machine. The six sigma level of defects rate becomes a 2.01 from a 1.61 at the beginning of the project.

• Journal of information and communication convergence engineering
• /
• v.12 no.1
• /
• pp.19-25
• /
• 2014

The wireless sensor networking standard DASH7 operates in low-power communication with a better transmission quality in active RFID networks. The DASH7 security standard supports public key cryptography. At present, the DASH7 standard uses the message authentication code in the network layer for authentication and integrity. However, its security standard is still in an incubation stage with respect to the implementation of a crypto exchange over a DASH7 network. Effective key management is an important factor for privacy and security. If organizations are not careful about where and how keys are stored, they leave the encrypted data vulnerable to theft. In this regard, we present a key management system designed for efficient key management through public key infrastructure authentication as well as a non-repudiation feature for the DASH7 standard. We analyze the performance of the proposed system on a basis of various performance criteria such as latency and throughput.

• Industrial Engineering and Management Systems
• /
• v.7 no.3
• /
• pp.214-227
• /
• 2008

Today's dynamic competitiveness requires an organization to improve its performance measurement and management. Quality Management Systems (QMS) abound, the main ones being: ISO series, Malcolm Baldridge National Quality Award (MBNQA), European Forum for Quality Management (EFQM), Six Sigma Business Scorecard and the Balanced Scorecard. Based on the literature, the IPMMM (Integrated Performance Measurement and Management Model) identified 7 key synthesized factors: leadership, strategy management and policy, customer and market, learning and growth, partnership and resources, internal processes and business results that are employed to investigate the key performance indicators of a car assembler using the Delphi methodology. In the 2 rounds of Delphi panels consisting of 20 senior management personnel, the $1^{st}$ round of 198 indicators in the IPMMM yielded 90 indicators. The $2^{nd}$ round yielded 43 performance indicators with 18 rated as critical based on the % assigned in the $1^{st}$ and $2^{nd}$ priority rating of "very important factor" and "key performance indicator" that must be ranked high on both of the priorities. The very critical indicators appeared to be: defect percentage and first time capability (tie in $1^{st}$ place) and revenue, goal setting, customer satisfaction index, on-time delivery, brand image, return on investment, Claim Occurrence Ratio, and debt being ranked from $3^{rd}$ to $10^{th}$. It can be surmised that an organization can identify and develop an appropriate set of performance indicators through the Delphi methodology and implement and manage them based on the Balanced Scorecard.