• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.55-61
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• 2009

Passive fitting of meso-structure and super-structures is a predominant requirement for the longevity and clinical success of osseointegrated dental implants. However, precision and passive fitting has been unpredictable with conventional methods of casting as well as for corrective techniques. Alternative to conventional techniques, electro discharge machining(EDM) is an advanced method introduced to dental technology to improve the passive fitting of implant prosthesis. In this technique material is removed by melting and vaporization in electric sparks. Regarding the efficacy of EDM, the application of this technique induces severe surface morphological and elemental alterations due to the high temperatures developed during machining, which vary between $10,000{\sim}20,000^{\circ}C$. The aim of this study was to investigate the morphological and elemental alterations induced by EDM process of casting dental gold alloy and non-precious alloy used for the production of implant-supported prosthesis. A conventional clinical dental casting alloys were used for experimental specimens patterns, which were divided in three groups, high fineness gold alloy(Au 75%, HG group), low fineness gold alloy(Au 55%, LG group) and nonprecious metal alloy(Ni-Cr, NP group). The UCLA type plastic abutment patterns were invested with conventional investment material and were cast in a centrifugal casting machine. Castings were sandblasted with $50{\mu}m\;Al_2O_3$. One casting specimen of each group was polished by conventional finishing(HGCON, LGCON, NPCON) and one specimen of each group was subjected to EDM in a system using Cu electrodes, kerosene as dielectric fluid in 10 min for gold alloy and 20 min for Ni-Cr alloy(HGEDM. LGEDM, NOEDM). The surface morphology of all specimens was studied under an energy dispersive X-ray spectrometer (EDS). The quantitative results from EDS analysis are presented on the HGEDM and LGEDM specimens a significant increase in C and Cu concentrations was found after EDM finishing. The different result was documented for C on the NPEDM with a significant uptake of O after EDM finishing, whereas Al, Si showed a significant decrease in their concentrations. EDS analysis showed a serious uptake of C and Cu after the EDM procedure in the alloys studied. The C uptake after the EDM process is a common finding and it is attributed to the decomposition of the dielectric fluid in the plasma column, probably due to the development of extremely high temperatures. The Cu uptake is readily explained from the decomposition of Cu electrodes, something which is also a common finding after the EDM procedure. However, all the aforementioned mechanisms require further research. The clinical implication of these findings is related with the biological and corrosion resistance of surfaces prepared by the EDM process.

• Spatial Information Research
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• v.12 no.3
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• pp.285-298
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• 2004

Transportation digital map has built based on NGIS (national geography institute's 1 :5000 digital database) which derived from the aerial photo materials. Transportation digital map is a part of National Transportation Database Building Project carried out by the Korea Transport Institute and Ministry of Construction and Transportation. Transportation digital map for the purpose of transportation plan and investment has been updated and corrected the NGIS database especially for road network. Transportation digital map database is essential basic data fully applied for transportation policy and planning. The database must be reliable and objective to be applied for national transportation policy decision and transportation analysis. In addition, it needs accuracy and currentness to reflect the road network for the survey year. To satisfy the purpose of the database, following steps are necessary first, data Production and building has to be done by guideline of survey and database building. Secondly, geometric and logical errors which can occur during the survey and database building should be carefully detected. Thirdly, sectional guideline for database examination and procedure needs to be set up systematically and coherently This study is about examination guidelines for section and procedure on nodes and links which are essential object in transportation digital map database. According to the type of error, consistent and systematic error examination can lead to quality guarantee for objective and reliable database.

• Journal of Global Scholars of Marketing Science
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• v.13
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• pp.71-88
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• 2004

Although the factors that affect the width of latitude of price acceptance is well documented, the attempt to develop a practice-oriented methodology to calibrate the region of price insensitivity (i.e., a latitude of price acceptance) for a given individual brand has been relatively rare. The researcher aims to try to full this gap by developing a conjoint analysis-based procedure that can be applied to many industries. Furthermore, we examine the difference in the latitude of price acceptance between on- and off-line transaction in stock industry in Korea. The conjoint analysis-based procedure was applied to measure the disaggregate price response curve for individual stock investment both on- and off line transaction channel. The curves from the samples enable us to estimate the individual choice probabilities corresponding to applied price points. Using t-test the differences in mean choice probabilities between the list price and another price point were tested, through which we can get the latitude of price acceptance for a given brand in stock market. These procedures were tested in on- and off-line stock market in South Korea. The results showed that investors on off-line channel have wider latitudes of price acceptance than the investors on on-line transaction system.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.133-141
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• 2005

In the resent years, the importance of VE (value engineering) and LCC (life cycle cost) analysis for apartment building construction projects has been fully recognized. Accordingly theoretical models, guidelines, and supporting software systems were developed for the value engineering and life cycle cost analysis for construction management including large building systems. However, the level of consensus on VE and LCC analysis results is still low due to the lack of reliable data on maintenance. This paper presents time dependent LCC model based value analysis method for rational investment decision making and design alternative selection for construction of apartment building. The proposed method incorporates a time dependent LCC model and a performance evaluation technique by fuzzy logic theory to properly handle the uncertainties associated with statistics data and to analyze the value of alternatives more rationally. The presented time dependent VE and LCC analysis procedure were applied to a real world project, and this case study is discussed in the paper. The model and the procedure presented in this study can greatly contribute to design value engineering alternative selection, the estimation of the life cycle cost, and the allocation of budget for apartment building construction projects.

• Korean Security Journal
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• no.6
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• pp.47-65
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• 2003

In Korea, Private security companies has steadily grown and amounts to 2,051 places as of November 30, 2002. Private security in korea is carrying out firm name role assignment to have held the police and public peace environment change factors for a standard faithfully, and protects social a little property that is a basic purpose, and it is spare no efforts in loss prevention. In spite of numeral increase of private security companies, private security companies have many problem. Moreover, they mostly did not have any remarkable in-house expertises in their own business under tough conditions. Under the unfavorable circumstances including insufficient investment and education in private security guard, there have been actually little further studies on private security business in practices. So this study mainly focused on addressing the installation security business managed by authorized companies, which amount to 96%(1,963 companies) of total 2,051 domestic security companies. Furthermore, the study formulated and modeled a series of business procedures in private security companies. A series of business procedures of private security companies can be modeled as follows : Setting of a business scope and aim market ${\Rightarrow}$ Marketing, Contact from customers(On-line or Off-line) ${\Rightarrow}$ Diagnosis of security target ${\Rightarrow}$ Submission of security operational plan ${\Rightarrow}$ Estimation of security operational plan ${\cdot}$ decision ${\Rightarrow}$ Contract ${\Rightarrow}$ Employment, selection of security guards ${\Rightarrow}$ Nomination of security guard instructors ${\Rightarrow}$ Education & training of security guards ${\Rightarrow}$ subscribe to insurance of damage liability ${\Rightarrow}$ Commitment and placement of security guards ${\Rightarrow}$ Establishment and preparation of security planning ${\Rightarrow}$ Field management and procurement of relevant security service.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.125-133
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• 2012

To make maximum benefit through the R&D investment, various methods is presented to support cooperating company in managing product information which reaches to conceptual design, detail design, production and a service from planning phase of production. Recently, the induction of PLM (Product Lifecycle Management) is being accelerated to design the enterprising system which is various from the idea phase for a product plan to the elimination through the life cycle of the product by the major companies. This study is focused on the research and development of the major companies which is producing products like sets, parts and equipment. This study proposes the process of product strategy, goods planning, development, information and the renovation of decision-making system.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.1
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• pp.143-150
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• 1996

The purpose of this study was to evaluate the tensile strength of solder joint between gold alloy and nickel-chromium alloy. The specimens were made with type III gold alloys and Ni-Cr-Be alloy and Degular Lot 2 solder. Eighteen paired specimens were made, and subdivided into three groups. Group I specimens were gold alloy-gold alloy combination, Group II specimens were gold alloy-Ni-Cr alloy combination, Group III specimens were Ni-Cr alloy-Ni-Cr alloy combination. Solder block were made with solder investment(Degussa A,G, Germany) and stored in room temperature for 24 hours. To reduce the formation of metallic oxide and increase wetting properties, flux was used before preheating and soldering procedure. The specimens were preheated at $650^{\circ}C$ and flux were applied again and gas-oxygen torch was used to solder the specimen. All soldered specimens were subjected to a tensile force in the Instron universal testing machine : the crosshead speed was 1 mm/mim. Tensile strength values of three soldered joint groups were 1. Gold alloy-Gold alloy solder joint : $$48.8kg/mm^2$$ 2. Gold alloy-Ni-Cr alloy solder joint : $$30.9kg/mm^2$$ 3. Ni-Cr alloy-Ni-Cr alloy solder joint : $$31.8kg/mm^2$$ The microscopic examination of fracture site showed cohesive and combination fracture modes in gold alloy specimens, but showed all adhesive fracture modes in Ni-Cr alloy containing specimens.

• The Journal of Information Systems
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• v.15 no.3
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• pp.1-34
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• 2006

The purpose of this study Is to develop empirically validated instrument for business model. The previous researches related to business model were almost taxonomies. And the focus of those researches were the classification by the degree of integration and innovation the origin, and the main source of revenue etc. In the emerging fields such as IT, e-commerce, and e-business, it tends to overlook methodological issue in its substantive relationships and also measurement. Business model is taken an interest in recent years. However, as the non-establishment of construct on business model has made no empirical study, this, study tries to develop an empirical validated instrument that identifies the dimensions of business model by uncovering meaningful group or categories. For this, the outlined domain of business model are defined as an organizational level that competes in the industry through the literature reviews. And the traits such as process integration, value chain reconstruction, strategic alliance with another business model, specialty in a certain wet sustainability of essential capabilities, differentiation, convertibility, customer orientation, revenue stream, newness, innovation leadership: and vision sharing are identified in those respective domains, and then the traits are classified into five dimensions such as interlinkageableness, valueness, functionalness, preemptiveness, and goalness by their characteristics. Generating items are continued on the basis of operationalization. Confirmatory factor analysis is performed in order to develop validated instrument with LISREL measurement model. Finally the instrument is developed through the previous procedure. The implication of this study is the first empirical effort to assess business model. The resulting instrument can be used with dependent variables in the future study related to business model. And the establishment of construct of business model is able to make a basis to rise an additional issue consequently. In the practical side, the instrument also can be employed as an assessment framework that can assess whether the expected value success or not. The instrument with the measurement can be used on competitor's business model, In. When an investment into a i-m with a specific business model, these instrument developed can be presented as the basic framework of assessment.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.96-110
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• 2008

Differing from civil engineering and construction, landscape architecture projects are far from efforts in operation and project management. Under the circumstances, it is worthwhile to adopt scope definition from project management for construction and civil engineering in some respects. First, scope definition is able to be conducted through a simple procedure without additional investment in capital and time. Second, the output produced by scope definition is very substantial. The research scrutinized scope definition procedures accompanied by landscape architecture project execution and derived various methods in order to help scope definition for efficient landscape architecture projects. Based on the literature review, a design case study, and an exert interview, the project success elements were developed consisting of 3 sections, 8 categories and 50 elements, grounded on the theoretical base of PDRI. The elements are expected to pave a way to an adequate level of scope definition among participants of landscape architecture projects and contribute in efficient project execution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.21-27
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• 2018

FRN (Full range Naphtha) is distilled from crude oil in a Naphtha Splitter Unit and is separated into the Light Straight Naphtha, Heavy Naphtha, and kerosene according to the boiling point in sequence. This separation is conducted using a series of binary-like columns. In this separation method, the energy consumed in the reboiler is used to separate the heaviest components and most of this energy is discarded as vapor condensation in the overhead cooler. In this study, the first two columns of the separation process are replaced with the Petlyuk column. A structural design was exercised by a stage to stage computation with an ideal tray efficiency in the equilibrium condition. Compared to the performance of a conventional system of 3-column model, the design outcome indicates that the procedure is simple and efficient because the composition of the liquid component in the column tray was designed to be similar to the equilibrium distillation curve. An analysis of the performance of the new process indicated an energy saving of 12.3% under same total number of trays and with a saving of the initial investment cost.