• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.1
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• pp.114-120
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• 2005

This paper studies procedures for bottleneck detection in closed queueing networks(CQN's) with multiple job classes. Bottlenecks refer to servers operating at $100\%$ utilization. For CQN's, this can occur as the population sizes approach infinity. Bottleneck detection reduces to a non-linear complementary problem which in important special cases may be interpreted as a Kuhn-Tucker set. Efficient computational procedures are provided.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.147-155
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• 2016

Industry 4.0's goal is the 'Smart Factory' that integrates and controls production process, procurement, distribution and service based on the fundamental technology such as internet of the things, cyber physical system, sensor, etc. Basic requirement for successful promotion of this Industry 4.0 is the large supply of semiconductor. However, company I who produces dicing blades has difficulty to meet the increasing demand and has hard time to increase revenue because its raw material includes high price diamond, and requires very complex and sensitive process for production. Therefore, this study is focused on understanding the problems and presenting optimal plan to increase productivity of dicing blade manufacturing processes. We carried out a study as follows to accomplish the above purposes. First, previous researches were investigated. Second, the bottlenecks in manufacturing processes were identified using simulation tool (Arena 14.3). Third, we calculate investment amount according to added equipments purchase and perform economic analysis according to cost and sales increase. Finally, we derive optimum plan for productivity improvement and analyze its expected effect. To summarize these results as follows : First, daily average blade production volume can be increased two times from 60 ea. to 120 ea. by performing mixing job in the day before. Second, work flow can be smoother due to reduced waiting time if more machines are added to improve setting process. It was found that average waiting time of 23 minutes can be reduced to around 9 minutes from current process. Third, it was found through simulation that the whole processing line can compose smoother production line by performing mixing process in advance, and add setting and sintering machines. In the course of this study, it was found that adding more machines to reduce waiting time is not the best alternative.

• International Commerce and Information Review
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• v.8 no.2
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• pp.187-210
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• 2006

China continues to experience an expansion of its e-Commerce industry. This is true both for B2C and for B2B sectors. B2C websites are created by various players. B2C E-commerce is divided into three categories in China: online direct sale, online retail, and online booking services. Online retail remains the major form of B2C business, and online booking services and online direct sale also maintained rapid growth. The rapid growth of B2C E-commerce in China was due to three factors. Firstly, the number of Internet users is increasing, which expands E-commerce user base. Secondly, users' acceptance and recognition of E-commerce are gradually increasing. Lastly, improvement on payment, logistics and credit also provides a better and better industrial environment for B2C e-commerce. The B2C sector has seen a low transaction volume in spite of its large number of websites. The B2B sectors has seen a higher transaction volume and more stable growth than the B2C sector. There is a wide range of the total market size estimated by different sources. China's C2C market witnessed rapid growth in 2005, the market growth may slow down in 2006 and 2007, due to heavy market competition, challenges to the business model and slow corporate user growth. But there is the bottlenecks in E-commerce in China. The purpose of this paper is contribute to development E-commerce in China by finding the solutions of the bottlenecks in E-commerce in China.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.39-44
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• 2008

This paper proposes a real-time geometric correction system based on a projector to project digital images onto deformable surface. Markers use to trace lots of corresponding points would spoil the projected image when the projector projects a digital image onto the surface because they leave marks on the surface. In addition, it is difficult to build a real-time geometric correction system since bottlenecks occur through the process of the geometric correction for projecting images. In this paper, we use invisible infrared markers and a vertex shader of GPU using Cg TookKit of NVIDIA in order to eliminate disadvantage and bottlenecks in the process of markers recognition so that it is possible to project natural correction images in real-time. As a result, this system overlays an interactive virtual texture onto the real paper by using the geometric transformation. Therefore, it is possible to develop variation of AR(Augmented Reality) based on digital contents systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.799-806
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• 2020

The rapid growth of smartphone-to-Internet of Things (IoT) connections and the explosive demand for data usage centered on mobile video are increasing day by day, and this increase in data usage creates many problems in the IP system. In a full-based environment, in which information requesters focus on information providers to receive information from specific servers, problems arise with bottlenecks and large data processing. To address this problem, CCN networking technology, a future network technology, has emerged as an alternative to CCN networking technology, which reduces bottlenecks that occur when requesting popular content through caching of intermediate nodes and increases network efficiency, and can be applied to military information and communication networks to address the problem of traffic concentration and the use of various surveillance equipment in full-based networks, such as scientific monitoring systems, and to provide more efficient content.

• Research in Community and Public Health Nursing
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• v.17 no.2
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• pp.195-209
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• 2006

Purpose: This study attempted to access the health promotion activities and employee's health promotion needs in workplaces. Methods: Subjects were 280 health care managers employed at small to large scale enterprises in national-wide areas of Korea. The instrument was a structured questionnaire included characteristics of workplace and respondents, health promotion activities, health promotion needs, and bottlenecks to operate programs. Data was analyzed using SAS 8.1 by applying $x^2-test$, t-test and ANOVA. Results: 1, 25.4% of the total workplaces employed health care managers. 2. Musculoskeletal management programs(49.6%) were the highest operating program. 3. The highest needs of health promotion programs were lifestyle management and disease prevention. 4. Health promotion activities were significantly different according to the type and size of workplaces. The programs were more frequently applied in manufacturing industries than non-manufacturing and in large-scale enterprises than small and middle-scale enterprises. 5. The needs of health promotion programs were high in non-manufacturing industries than manufacturing industries in all programs. 6. The major bottlenecks to operate programs were the difficulty in securing time, lack of budgets and lack of legal regulations. Conclusions: Health promotion activities were linked to their work environments including budgets, time, and law. Therefore, to operate effective health promotion programs in workplaces, various health promotion programs are required to be developed and systems for governmental support and management should be established.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1369-1377
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• 2020

Objective: The main objectives of the present study were to assess the genetic diversity, population structure and to appraise the efficiency of ongoing selective breeding program in the closed nucleus herd of Nellore sheep through pedigree analysis. Methods: Information utilized in the study was collected from the pedigree records of Livestock Research Station, Palamaner during the period from 1989 to 2016. Genealogical parameters like generation interval, pedigree completeness, inbreeding level, average relatedness among the animals and genetic conservation index were estimated based on gene origin probabilities. Lambs born during 2012 and 2016 were considered as reference population. Two animal models either with the use of F_i or ΔF_i as linear co-variables were evaluated to know the effects of inbreeding on the growth traits of Nellore sheep. Results: Average generation interval and realized effective population size for the reference cohort were estimated as 3.38±0.10 and 91.56±1.58, respectively and the average inbreeding coefficient for reference population was 3.32%. Similarly, the effective number of founders, ancestors and founder genome equivalent of the reference population were observed as 47, 37, and 22.48, respectively. Fifty per cent of the genetic variability was explained by 14 influential ancestors in the reference cohort. The ratio f_e/f_a obtained in the study was 1.21, which is an indicator of bottlenecks in the population. The number of equivalent generations obtained in the study was 4.23 and this estimate suggested the fair depth of the pedigree. Conclusion: Study suggested that the population had decent levels of genetic diversity and a non-significant influence of inbreeding coefficient on growth traits of Nellore lambs. However, small portion of genetic diversity was lost due to a disproportionate contribution of founders and bottlenecks. Hence, breeding strategies which improve the genetic gain, widens the selection process and with optimum levels of inbreeding are recommended for the herd.

• Proceedings of the Korean DIstribution Association Conference
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• 2001.02a
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• pp.49-63
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• 2001

Digital revolution is switching existing paradigms such as analogue to digital, off-line to on-line. Electronic commerce is the single most significant element to change the economic and social environments. After the middle of 1990's, electronic commerce have introduced two scenes; dramatic change of the existing distribution surroundings ad noticeable achievement of the economic advance and social efficiency. But, in the same scene, electronic commerce can be a threat to business condition, especially logistics management. In this study, we've done an empirical study to the experts who are in the real field; B2C and TPL(third party logistics). By the result of the study, we found five factors which means logistics bottlenecks to electronic commerce between business to consumer(B2C) as like; specialization and information, service quality and service variety, benefit-cost, reliability, and legal and policy factor.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.627-638
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• 2008

With the shift of the electric power industry from a regulated monopoly structure to a competitive market environment, the focus of the transmission expansion planning has been moving from reliability-driven transmission expansion to market-based transmission expansion. In market-based transmission expansion, however, a growing demand for electricity, an increasing number of transmission bottlenecks, and the falling levels of transmission investment have created the need for an incentive to motivate investors. The expectation of profit serves as a motivational factor for market participants to invest in transmission expansion in a competitive market. To promote investment in transmission expansion, there is an increasing need for a systematic method to examine transmission expansion for investment incentives from multiple perspectives. In this paper, the transmission expansion problem in a competitive market environment is formulated from ISO and investors' perspectives. The proposed method uses parametric analysis to analyze benefits for investors to identify the most profitable location and amount for transmission addition. Numerical results are presented to demonstrate the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.68-69
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• 2015

Traditional External Insulation Finishing System(EIFS) is applied to apartment construction by performing structural framework and insulation finishing work sequentially. Separate execution of the three works increases construction cost and duration. Concurrent construction method of EIFS, which performs framework and insulation finishing work simultaneously, is introduced in order to solve these problems. However, the introduced method is exposed to the risk of construction delay caused by bottlenecks due to interacting processes and resources. Therefore, this paper presents a simulation model suitable for estimating work productivity of the concurrent construction by considering predecessor and successor processes to optimize resource allocation and minimize construction delay.