• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.172-173
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• 2015

Construction project involves numerous repetitive operations. Especially in high-rise and apartment houses projects, the amount of repetitive operations increase and a preceding operations delay causes serious damage to the total duration of the project. This study deducts work delay factors by site engineer interview and survey. The study analyzes daily report data to deduct crucial processes affecting masonry work which has been investigated to be one of preliminary processes conducted at the beginning of finish work.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.254-257
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• 2003

It is common to experience delays during construction projects. Delays can ca use substantial damages to an owner as well as contractors and is the sources of frequent disputes and claims. Many studies have been carried out to assess the causes of delays in construction projects. They are found to be almost similar, except some prevailed local condition. Most of the common construction delay factors are attributed to design faults, incompetent contractor, lack of team accountability etc. To minimize or eliminate the delay we have to follow the recognized fundamental principles of management such as: cost-time relationship, time priority, accountability, rewards, innovative thinking etc. The root causes of delays found out in this paper are not so much different than other previous study. If the implementing agencies properly followed the, fundamental management principles and some other related corrections as recommended in the paper, much construction delays can be avoided.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1188-1195
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• 2006

This paper examines the critical air temperature at which frost formation does not occur on a cold plate in order to improve the efficiency of a heat pump. The critical air temperature on test points is obtained from numerical analysis and a correlation of the critical air temperature is derived as a function of frosting factors (air absolute humidity, air velocity, and cold plate temperature) by least square method. Experiments are carried out to verify the correlation proposed in this study, and the prediction obtained with the correlation agrees well with the experimental data. Based on the correlation, we propose the non-frosting regions according to frosting factors.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2520-2527
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• 2000

An improved transition density propagation method for power estimation is proposed. The power estimation for the zero delay model is a proper criteria for the.lower boutldlIry for power consumption. A transition propagation method, including the zero delay model as a lower boundary for power stimation was studied. However, there were some redundancy factors in the process of transition density propagation. Hence this paper will explore the transition density propagation behavior to eliminate the redundancy factors and present theirriprQved estimation methodology for the signal transition density. The experiments show that the proposed method has comparably better estimation accuracy than the conventional methods.

• Journal of Information Technology Services
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• v.3 no.2
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• pp.65-84
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• 2004

This research analyzes the causes of delay and resulting additional expenses on the IS project in the public sector, and then proposes some solutions to the problem. Through a field study, the research found that the causes include employer's attitude, the leadership and risk management ability of the project manager, and qualifications of project members. In order to avoid those problems, the project manager should secure various communication channels and good relationship between the employee and the contractor.

• Korean System Dynamics Review
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• v.1 no.1
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• pp.29-56
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• 2000

During the past few years, cyberspace and electronic commerce has been expanding throughout the world rapidly. The purpose of this paper is to find out policy leverages for boosting up cyberspace and electronic commerce using system dynamics simulation modeling approach. The system dynamics simulation model developed in this paper allows analysis of both the effect of factors on dynamic growth pattern of cyberspace as well as the effect of time delay in information processing, money transfer and delivery on model behavior. Finding of this study is that capacity of information infrastructure and size of cyberspace population are key factors of cyberspace growth. Also, reducing time delay in information flow, money flow, and delivery flow is an important policy leverages for growth of electronic commerce.

• Water for future
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• v.23 no.4
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• pp.459-466
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• 1990

In the Ice Valley, it freeze in summer season. However, there is no ice during winter. In order to clarify the phenomenon of unusual temperature, numerical experiments were conducted using the coupled equations of fluid flow and heat transfer. The results demonstrated that temperature inversion in the Ice Valley is primarily due to delay of the groundwater temperature. Also, the results of the simulation suggest that major factors affecting the delay are the topographical configuration, geological factors and groundwater flow system, combined with groundwater recharge and discharge systems.

• Korea Journal of Hospital Management
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• v.7 no.3
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• pp.44-62
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• 2002

Advanced surgical technology demands more precise, meticulous, and time-consuming procedures. In addition, the patient's preference of tertiary health providers makes over crowding of the University Hospitals. Therefore, it has been necessary to maximize utilization of the operating room of such hospitals to accommodate these requirements. This study, targeting 1,302 surgical cases performed in 22 operating rooms at a university hospital in Seoul from October 8 to November 1, 2001, analyzed reasons for delay, and factors that caused delayed use of operating rooms. This study also assessed that the rate of operating room use would increase if the sources for possible reform were improved. 1. Among total of 1,302 cases of surgery, the incidence of surgeries in which there were no time delays and no factors for delay were discovered is 71.4% or 930 cases: the incidence in which surgeries were delayed was 28.6% or 372 cases. 2. As results of logistic regression for delay, procedures involving women were delayed 1.4 times more frequently than those of men. Compared to Department A, Department B was 1.8 times more likely to be delayed, and Department H was 0.4 times less likely to be delayed. Regional anesthesia was 2.4 times more likely to be delayed than general anesthesia, and surgeries that PCA was applied were 0.6 times less likely to be delayed than those when it was not. Surgeries performed on the Thursday were 1.7 times more likely to be delayed than those performed on the Monday. Compared to surgeries performed between 07:00-07:59, those performed between 08:00-08:29 were 4.3 times higher. 3. The reasons for delay were related to surgeon, surgical department, patient, anesthesia, administrative system, sick ward, and support services. Among these, 5,755 minutes for 276 delayed cases could be resolved easily, and resolving delays of 3,320 minutes for 131 cases would be more difficult. Among the causes for delay that could be improved, delays due to patient's transfer and surgeon's factor were the most common, 21.6% and 17.4% respectively. 4. If resolvable delays are improved, pre-anesthesia room is administered, and regional anesthesia and PCA are done ahead of time, use of emergency operating rooms will increase, we can increase overall utilization by 4.09%, we will save 744 minutes a day, we can reduce the time the operation room is used after 4 PM by 35%, and we can resolve the operation cancellations due to insufficient operating rooms. For the increase in the use of operating rooms, we need to maximally decrease the delays that could be improved, by allocating block time based on used totals hours of elective cases, giving accurate information on surgery schedule, voluntary cooperation by staff participating in surgeries in reducing delay time, and the hospital management's will to improve delay.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.113-118
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• 2010

Purpose: Prolonged stay in the emergency department (ED), which is closely related with the time interval from the ED visit to a decision to admit, might be associated with poor outcomes for trauma patients and with overcrowding of the ED. Therefore, we examined the factors affecting the delay in the decision to admit severe trauma patients. Also, a multidisciplinary department system was preliminarily evaluated to see if it could reduce the time from triage to the admission decision. Methods: A retrospective observational study was conducted at a tertiary care university hospital without a specialized trauma team or specialized trauma surgeons from January 2009 to March 2010. Severe trauma patients with an International Classification of Disease Based Injury Severity Score (ICISS) below 0.9 were included. A multivariable logistic regression analysis was used to find independent variables associated with a delay in the decision for admission which was defined as the time interval between ED arrival and admission decision exceeded 4 hours. We also simulated the time from triage to the decision for admission by a multidisciplinary department system. Results: A total of 89 patients were enrolled. The average time from triage to the admission decision was $5.2{\pm}7.1$ hours and the average length of the ED stay was $9.0{\pm}11.5$ hours. The rate of decision delay for admission was 31.5%. A multivariable regression analysis revealed that multiple trauma (odds ratio [OR]: 30.6, 95%; confidence interval [CI]: 3.18-294.71), emergency operation (OR: 0.55, 95%; CI: 0.01-0.96), and treatment in the Department of Neurosurgery (OR: 0.07, 95%; CI: 0.01-0.78) were significantly associated with the decision delay. In a simulation based on a multidisciplinary department system, the virtual time from triage to admission decision was $2.1{\pm}1.5$ hours. Conclusion: In the ED, patients with severe trauma, multiple trauma was a significant factor causing a delay in the admission decision. On the other hand, emergency operation and treatment in Department of Neurosurgery were negatively associated with the delay. The simulated time from triage to the decision for admission by a multidisciplinary department system was 3 hours shorter than the real one.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.434-442
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• 2012

Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with themaximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.