• International Commerce and Information Review
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• v.18 no.4
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• pp.285-310
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• 2016

The purpose of this study empirically verified impact of strategic and operational integration between first-tier supplier and their supplier and strategic and operational integration between first-tier supplier and their buyer on operation performance. In order to achieve our goal, we tested reliability, validity and path coefficient using structural equation modeling-partial least square (SEM-PLS) over 284 first-tier manufacturing suppliers data that Korea Productivity Center (KPC) surveyed in 2013. This study results indicated that operational integration between first-tier supplier and their supplier or buyer has positive impact on production process flexibility. Meanwhile, strategic integration between first-tier supplier and buyer has positive impact on production flexibility. On the other hand, strategic integration between first-tier supplier and supplier has negative impact on production flexibility. And production process flexibility has positive impact on production flexibility. By empirically testing to departmentalize level and scope of supply chain integration, this study has academic and managerial implications from first-tier perspective on.

• Journal of Climate Change Research
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• v.3 no.3
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• pp.195-209
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• 2012

There are four differentiated levels to quantify the amount of greenhouse gas emissions from a facility, which are Tier 1 to 4 based on the IPCC guidelines. In this study, the emission estimates from all tier levels were calculated to compare their total $CO_2$ emission results among themselves for seven facilities, including three sectors of electricity generation, municipal solid waste incineration, and cement manufacturing for three months between February and May 2011. Generally the measured $CO_2$ emissions by Tier 4 were higher than the calculated $CO_2$ emissions by Tier 3, which had been also observed for the power plants in the USA. It was found out that to obtain more reliable estimation for Tier 3, accurate analysis of the composition of the fuel used should be carried out. It was suggested that further refinement on the administrative guidelines be made to make it more robust.

• Journal of the Korea Society for Simulation
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• v.26 no.2
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• pp.31-39
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• 2017

This paper analyses the effectiveness of Kill Chain (KC) and Korea Air and Missile Defense (KAMD), also known as the K2 systems, using monte carlo simulation. It is assumed that the K2 systems are consisted with unitary KC and multi-layered (upper-tier and lower-tier) KAMD. And each system has two or three arbitrary weapon systems and its combination makes 12 scenarios. Measures of effectiveness (MOE) of the K2 systems were defined as ratio of eliminated ballistic missiles from total threats. And total cost was calculated by number of weapon launched and its unit cost. MOE and total cost of the K2 systems were estimated using monte carlo simulation with a thousand iteration for each scenario. Cost-effectiveness analysis was performed and the best candidate was selected using fixed effectiveness approach. As a result, the performances of KC are prime factor that affects both effectiveness and total cost of the K2 systems. It is also, acquired proper level of lower-tier KAMD to achieve desired defense effectiveness. For future work, it needs to be performed cost-effectiveness analysis based on practical specification and life cycle cost of weapon systems.

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.213-230
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• 2020

Until now, various educational budgets, facilities, and programs have been put into school education, but the results have not been clearly evaluated. This study presents a model to analyze the effectiveness of educational support for students in high schools across the country. In this model, we first use EM cluster analysis to make clusters with similar inputs for school operation, and then calculate the relative efficiency in each cluster by using Network DEA analysis. The Network DEA analysis has a two-stage structure where the first stage uses six inputs in terms of school infrastructure to generate outputs such as the number of academic persistence. In the Network DEA analysis, the second stage uses 10 inputs in terms of school programs to generate outputs such as the number of enrollees to higher learning and the number of employees and per capita usage of library as the connection variable. Based on the efficiency analysis results, Tier analysis is performed by applying the Euclidean distance to select targets for benchmarking. In this study, we applied the model to analyze the efficiency of educational support by collecting data regarding student education support in general and vocational high school nationwide. The stepwise benchmarking method proposed that the target be selected for efficiency improvement step by step, taking into account inefficient school elements to complement the problem of the choice of benchmarking targets. Based on this study, it is expected that schools with low efficiency of educational support for students will be used as basic data for stepwise benchmarking for efficient operation of educational support for students.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.540-547
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• 2019

Purpose: This paper is for the improvement of the fire gate performance that occurs between the construction company and the residents. A survey was conducted on experts in the construction to prepare the causes and measures for the suit. Method: The application of the Analytic Hierarchy Process(AHP) resulted in the following conclusions. Results: TIn the 2nd tier, 28percent of the "strengthening standards for installation of fire prevention zones" included in the "institutional strengthening of stnadards" of the 1st tier had higher importance. In the 3rd tier, "strengthening the installation standards by floor area" and "strengthening the standard of fire-resistant structures" showed high importance. Conclusion: The results suggest that detailed legal criteria for detailed installation criteria with varying site conditions are needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1725-1733
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• 2012

This paper describes the design and implementation of a 3-tiered proxy driving system utilizing smartphones. This system provides customers with a convenient request facility, and enables proxy drivers to provide a prompt service based on customer's location information. Implemented system supports two methods such as the existing phone-call and the online requesting method using smartphones. Performance analysis shows that the higher the ratio of online requests, the greater the effect of decreasing of phone jockey's workloads and the reduction of request processing time through the automation of receipt and processing. From a proxy driver company's standpoint, this system minimizes the increase of phone jockeys, and improves customer satisfaction through good service quality. This system also helps the company reduce the cost and increase the market share.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5A
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• pp.517-525
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• 2008

In this paper, we cary out system level simulations to investigate the effect of cell shape(i.e., different base station displacements in the two directions defined by the street grid) on minimizing transmitter power, interference power, and blocking probability for CDMA system in urban microcellular environments. In urban microcell, path loss to the base station depends on the orientation of the street where the mobile is located. Interference from mobile stations to the base station in the reference cell is considered up to second tier. The wrap around method is used to include the second tier interference with realistic computational complexity without reducing the accuracy of interference calculations. The investigation shows that the transmitter power, interference power, and blocking probability in a cell can be reduced by proper selection of the efficient cell shape.

• Spatial Information Research
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• v.8 no.2
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• pp.213-232
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• 2000

It is important to scrutinize spatial patterns in crime analysis since crime data has geographical attribute in itself. We focus on the development of ¨Crime Analysis GIS¨ prototype which can discover spatial patterns in crime data by integrating mapping functions of GIS and spatial analysis techniques. The structure of this system involves integration of DBMS and GIS, and the major functions of the system include (i) exploring spatial distribution of point data, (ii) mapping hot-spot, (iii) clustering analysis of crime occurrence, and (iv) analyzing aggregated areal data. The process of design and implementation of this system is based on object-oriented methodologies. A web-based extension of the prototype using 3-tier architecture is currently under development.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.3
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• pp.232-237
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• 2013

The aim of this study is to structuralize a model of the factors determining the quality of nursing care perceived by the director or manager of a long-term care facilities (hospitalization of patients) using FSM(Fuzzy Structural Modeling), employed in structuralizing social systems. The results were as follows: first, quality in the top tier was shown to be connected with job commitment, commitment to the organization, work experience, care skills, knowledge about the elderly, training and education, which are factors in the middle tier; and second, the structure of the middle tier (job commitment, commitment to the organization, work experience, care skills, knowledge about the elderly, training and education) either showed a connection with the lower tier, which includes employment type, job satisfaction, leadership, relationship with users and workplace relationships, or showed a connection among the factors within. These results confirmed the following: first, care skills and knowledge about the elderly, which demonstrate the job expertise of caregivers, showed a connection with service quality based on work experience; second, job commitment in the middle tier was observed to affect various factors in the same tier such as care skills, knowledge about the elderly, training and education amongst others, and it was determined that it is an important determining factor in service quality. Lastly, a meaningful result was shown in relation to leadership. The leadership skills of the director of the facilities had a connection with the care caregivers' commitment to the organization, which had a connection with service quality. This structure showed the kind of role the director must play in order to improve service quality.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.657-665
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• 2010

Carbon dioxide ($CO_2$) is known to be a major greenhouse gas partially emitted from waste combustion facilities. According to the greenhouse gas emission inventory in Korea, the quantity of the gas emitted from waste sector in 2005 represents approximately 2.5 percent of all domestic greenhouse gas emission. Currently, the emission rate of greenhouse gas from the waste sector is relatively constant partly because of both the reduced waste disposal in landfills and the increased amounts of waste materials for recycling. However, the greenhouse gas emission rate in waste sectors is anticipated to continually increase, mainly due to increased incineration of solid waste. The objective of this study was to analyze the property of Municipal Solid Waste (MSW) and estimate $CO_2$ emissions from domestic MSW incineration facilities. The $CO_2$ emission rates obtained from the facilities were surveyed, along with other two methods, including Tier 2a based on 2006 IPCC Guideline default emission factor and Tier 3 based on facility specific value. The $CO_2$ emission rates were calculated by using $CO_2$ concentrations and gas flows measured from the stacks. Other parameters such as waste composition, dry matter content, carbon content, oxidation coefficient of waste were included for the calculation. The $CO_2$ average emission rate by the Tier 2a was 34,545 ton/y, while Tier 3 was 31,066 ton/y. Based on this study, we conclude that Tier 2a was overestimated by 11.2 percent for the $CO_2$ emission observed by Tier 3. Further study is still needed to determine accurate $CO_2$ emission rates from municipal solid waste incineration facilities and other various combustion facilities by obtaining country-specific emission factor, rather than relying on IPCC default emission factor.