• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1859-1864
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• 2004

An effective methodology is reported for the optimal design of multisite batch production/transportation and storage networks under uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, internally consumed, transported to or from other plant sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between plant sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of large-scale supply chain system.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.537-544
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• 2010

Anchorage control in orthodontic treatment is an important factor affecting treatment results. In the conventional approach, intra-oral anchorage such as application of differential force and moment, Nance holding arch and lingual arch, as well as extra-oral anchorage such as head gear were used for anchorage reinforcement. However, these anchorages may result in undesired tooth movement and require patient cooperation. To overcome these disadvantages, skeletal anchorage system was introduced as orthodontic anchorage. Types of skeletal anchorage include implant, onplant, miniplate and miniscrew. Especially, miniscrew has many advantages such as reduced patient cooperation, low cost and easy placement. Recently, it is successfully used in orthodontic treatment. This cases were treated using orthodontic miniscrews for retraction of ectopically erupting maxillary canine and impacted mandibular canine and intrusion of maxillary incisors.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.226-234
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• 2004

Dynamic nature of the A/E/C industry, rapidly changing global market environment, and lowest cost competitive bidding make it difficult to survive in global engineering markets. To understand of the global design&engineering market, a case study has been undertaken. The top 150 global design forms represented in the ENR(Engineering News Record) from 1995 to 2003 are classified three groups for the case study, First group is the firms that its rank is getting raised from 1995. Second group is the firms keep holding its rank from 1994 until 2003. Third group is the firms that its rank has gone down from 1995 until 2003. However, finding key factors and changing business strategies of successful top design fm are the fundamental goals in this paper, After examined case study, this paper concludes and suggests that professionalization, M&A strategies, patrons of government, and academic supporting are needed to be succeeding in the global design & engineering industry.

• Archives of design research
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• v.5 no.1
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• pp.7-20
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and recei\ulcornerves pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective fina\ulcornerncial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper de\ulcornervlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine bygeneralization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers aro~nd the country.

• Archives of design research
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• v.5 no.1
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• pp.21-36
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and receives pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective financial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper devlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine by generalization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers around the country.

• Journal of Powder Materials
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• v.24 no.3
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• pp.235-241
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• 2017

Titanium alloys have high specific strength, excellent corrosion and wear resistance, as well as high heat-resistant strength compared to conventional steel materials. As intermetallic compounds based on Ti, TiAl alloys are becoming increasingly popular in the aerospace field because these alloys have low density and high creep properties. In spite of those advantages, the low ductility at room temperature and difficult machining performance of TiAl and $Ti_3Al$ materials has limited their potential applications. Titanium powder can be used in such cases for weight and cost reduction. Herein, pre-forms of Ti-Al-xMn powder alloys are fabricated by compression forming. In this process, Ti powder is added to Al and Mn powders and compressed, and the resulting mixture is subjected to various sintering temperature and holding times. The density of the powder-sintered specimens is measured and evaluated by correlation with phase formation, Mn addition, Kirkendall void, etc. Strong Al-Mn reactions can restrain Kirkendall void formation in Ti-Al-xMn powder alloys and result in increased density of the powder alloys. The effect of Al-Mn reactions and microstructural changes as well as Mn addition on the high-temperature compression properties are also analyzed for the Ti-Al-xMn powder alloys.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.956-962
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• 2005

This paper presents an integrated analysis of production and financing decisions. We assume that a cash storage unit is installed to manage the cash flows related with production activities such as raw material procurement, process operating setup, Inventory holding cost and finished product sales. Temporarily financial investments are allowed for more profit. The production plant is modeled by the Batch-Storage Network with Recycle Streams in Yi and Reklaitis (2003). The objective function of the optimization is minimizing the opportunity costs of annualized capital investment and cash/material inventory while maximizing stockholder's benefit. No depletion of all the material and cash storage units is major constraints of the optimization. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the cash and material inventory holdups. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two subproblems and analytical lot sizing equations under a mild assumption about the cash flow pattern of stockholder's dividend. The first subproblem is a separable concave minimization network flow problem whose solution yields the average material flow rates through the networks. The second subproblem determines the decisions about financial Investment. Finally, production and financial transaction lot sizes and startup times can be determined by analytical expressions as far as the average flow rates are calculated. The optimal production lot and storage sizes considering financial factors are smaller than those without such consideration. An illustrative example is presented to demonstrate the results obtainable using this approach.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.537-544
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• 2004

An effective methodology is reported for determining the optimal lot size of batch processing and storage networks which include uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, infernally consumed, transported to or from other sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sires while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of the global supply chain.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.5
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• pp.43-50
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• 2002

To improve the current waveform of diode rectifiers, we propose a new operating principle for the voltage -doubler diode rectifiers. In the conventional voltage-doubler rectifier circuit, relatively large capacitors are used to boost the output voltage, while the proposed circuit uses smaller ones and a small reactor not to boost the output voltage but improve the input current waveform. A high input power factor of 97[%] and an efficiency of 98[%] are also obtained. The harmonic guide lines of proposed rectifier is no interfered with inverter switching, resulting in a simple, reliable and low-cost ac-to dc converters in comparison with the boost-type current-improving circuits.It compared conventional pulse-widthmodulated(PWM)inverter with half pulse-widthmodulated (HPWM) inverter. Proposed HPWM inverter eliminated dead-time by lowering switchingloss and holding over-shooting.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.30-34
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• 1976

In general the chemical composition of glass ceramics in Li2O-Al2O3-SiO2 system is similar to the composition of $\beta$-spodumene (Li2O-Al2O3-4SiO2). With the object to manufacture the glass ceramics which can be produced in the domestic pot the composition of glass was so settled at 1.0 Li2O.0.9Al2O3.6.0SiO2 in order to reduce the contents of Li2O, to prevent the corrosion of the pot and to decrease the cost of raw materials. 0.2 mole and 0.1 mole of the mixture of TiO2 and ZrO2 as nucleants were added to the basic composition of 1.0 Li2O-0.9Al2O3-6.0SiO2. Each sample was divided into two kinds with a TiO2/ZrO2 ratio of 2 to 1 and the other with a TiO2/ZrO2 ratio fo 1 to 1. Thermal expansion coefficient, the most important property of glass ceramics, was tested. The softening point and the melting point of the samples were observed by the use of a heating microscope. The results obtained were as follows. The manufacturing of glass ceramics seems to be possible in the industrial plant using the domestic pot. 1) The composition of the glass which can be melted in the domestic pot process was near 1.0 Li2O.0.9Al2O3.6.0SiO2. 2) The temperature range of crystal creation and crystal growth was between 850-94$0^{\circ}C$, and 5 hours holding the samples at the temperature range was enough to crystallize them. The major crystal was $\beta$-spdumene and there existed petalite partialy. 3) The thermal expansion coefficient fo the crystallized glass was negative. 4) The deforming point of the crystallized glass was 1435$^{\circ}C$.