• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.58-72
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• 2009

The main activities of container terminals are to load container freights to vessels, discharge them from vessels, and store them in the storage yard. Container terminals make many operational plans to execute these functions effectively. If the plans do not consider enough the loads of related resources, they may have low actualities. This study discusses the optimal yard planning model which considers various resources, such as the storage yard, yard cranes, internal vehicles, and travel lanes, in container terminals. The model determines the groups and amounts of containers which are stored in each storage block by using the resource profile. The yard planning problem is represented to the multi-commodity minimal cost flow problem and is formulated to the linear programming model. In order to explain the application of the mathematical model, the numerical examples are presented. Additionally, the relationship between the average load ratio and the relocation ratio is discussed.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.75-81
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• 2001

MCVD(modified chemical vapor deposition) used in making optical-fiber currently utilizes the hydrogen-oxygen burner as a energy supply source. To improve the productivity and to reduce the manufacturing cost of optical-fiber, a natural gas-oxygen burner has been developed. The manufacturing processes of optical-fiber consist of vapor deposition, collapse and drawing processes. Among these processes, the vapor deposition and the collapse processes are important in terms of improving the productivity and saving the production cost. The vapor deposition and collapse processes are performed by combustion heat and flame force supplied by a burner. So the flame force of the burner used in these processes is required to have an optimal and consistent value in order to allow uniform heating and collapse of quartz tube. In this regard, the momentum ratio of natural gas and oxygen has been optimally determined by modification of a burner and the inlet flow pass also has been modified.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.10
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• pp.851-857
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• 2002

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi~level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40%. So, we focused how to reduce the consumption of raw slurry In this paper, we presented the pH changes of diluted slurry and pH control as a function of KOH contents. Also, the removal rates of slurry with different dilution ratio were investigated. Finally, the CMP characteristics were discussed as a function of silica (SiO$_2$) abrasive contents.

• Journal of Industrial Technology
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• v.30 no.B
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• pp.11-16
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• 2010

To provide a development strategy on the method which assesses a potential risk of nationwide emerging IT infrastructure in planning and design phase, and to classify the assessment result into 5 levels is the goal of this research. The development strategy provided in this paper could improve a benefit-cost-ratio of investments on emerging IT infrastructure. With a premature assessment of the potential risks of a nationwide emerging IT infrastructure which needs astronomical amount of public funds, it could show a way of systematic investments on security systems and improve a benefit-cost-ratio of investments on emerging IT infrastructure. Also, this approach might improve the safety of nationwide IT infrastructure. It could identify and provide an optimized solution for the potential risks of nationwide IT infrastructure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.18-22
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• 2002

CMP(chemical mechanical polishing) process has attracted as an essential technology of multilevel interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40%. So, we focused that it has how to reduce the consumption of raw slurry. In this paper, we presented the pH changes of diluted slurry and pH control as a function of KOH contents. Also, the removal rates of slurry with different dilution ratio was investigated. Finally, CMP the characteristics as a function of silica($SiO_2$) abrasive contents were discussed.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.221-228
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• 2012

This paper analyzed twenty-six production-related KPI(Key Performance indicator) factors of business diagnosis, such as personnel, equipment, materials, operations and quality affecting company business competition to 186 small machinery manufacturers in 2010. Also, we explained the concept of Business Positioning and divided research subjects into four Business Positioning Groups formed break-even point ratio & fixed cost ratio to sales and then we compared between the 4 groups using Logistic Regression analysis by SAS statistical software package. The objective of this study is two-fold. The first is to find out production-related KPI factor of superior Business Positioning Group. The second is to suggest improvement ways for small manufacturers in order to get better profitable Business Positioning.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.327-333
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• 2010

This study examines the impact different proxies of agency costs have on companies under different governance approaches. The two specific proxies of agency costs used include: (i) the ratio of operating expenses to annual sales; and (ii) the ratio of annual sales to total assets. Our study is based on earlier works of Ang et al. (2000) and Fleming et al. (2005). A comparison of results for small unlisted companies both in US and Australia indicate that agency cost measures have statistically: (1) different result under rule-based governance mechanisms; and (2) the same results under principle-based governance mechanisms. Our findings support the view that the effectiveness different measures of agency cost is dependent on country specific governance facto as well as on the governance approaches adopted. Our results offer insights to both practitioners and policy makers regarding the usefulness of different proxies of agency costs when companies adopt principle-based corporate governance approaches versus rule-based approaches.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.17
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• pp.47-54
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• 1988

Korean National Railroad(K.N.R) playing a important role in land transportation gives us many problems to solve considering proper management of National Budget and development of the state of operation by maintaining train parts rationally as public services. According this study is to show inventory provision system for deciding the safety inventory level as the better rational method. Bibliography for this study is limited to only three kinds of seven brakes-shoe which is produced by T workshop in Korean National Railroad. To reduce the holding cost coming from the want of the stock and shortage cost of the stock expected. This study is to present a ratio of shortage on the stock permitted for the last definite period and the demand result forecast per month.

• Current Optics and Photonics
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• v.7 no.6
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• pp.683-691
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• 2023

A typical terahertz time-domain spectroscopy system requires large, expensive, and heavy hardware such as a lock-in amplifier and a function generator. In this study, we replaced the lock-in amplifier and the function generator with a single sound card built into a typical desktop computer to significantly reduce the system size, weight, and cost. The sound card serves two purposes: 1 kHz chopping signal generation and raw data acquisition. A unique software lock-in (Python coding program to eliminate noise from raw data) method was developed and successfully extracted THz time-domain signals with a signal-to-noise ratio of ~40,000 (the intensity ratio between the peak and average noise levels). The built-in sound card with the software lock-in method exhibited sufficiently good performance compared with the hardware-based method.

• The Journal of Fisheries Business Administration
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• v.44 no.3
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• pp.103-109
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• 2013

This paper analyzed that the economic effectiveness of the artificial fish reef project in the Tae-an Marine Ranching. Benefit-cost(B/C) model used to indicate the effects of economic valuation. B/C model is based on the sub-models which are Benefit Cost Ratio(BCR), Net Present Value(NPV) and Internal Ration of Return(IRR). First, the Sum of Incremental Benefit and Cost for total vessel by year in Artificial Fish Reef Area(AFRA) estimated 2,381 million won. And then, using 5.5% discounting rates and the survey data, the sub-models showed economically feasible in the all of analysis and analyzed the results as follows. BCR is 2.66, NPV is 28,014million won, and IRR is 22.78%. In conclusion, these results indicated that the artificial fish reef project in Tae-an Marine Ranching would be increase the income of fishermen as well as fish biomass.