• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.31-40
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• 2009

Some road charges toll to finance the cost or to manage traffic congestion. With a growth of PPI projects, toll roads would be increase continuously. Tolls have a considerable influence on user's route choice, and sometimes can affect to the departure time and even to mode choice. For modelling toll roads, user's WTP or VOT has an important role and it is general that VOT is equivalent to the wages of workers. The current way of modelling technique yields various toll price elasticity from low to high. When there exist few alternative routes, unrealistic result that all traffic assigned to some shortest path may occur. The toll price elasticity can be influenced by alternative route and congestion level, but some result shows nearly unrealistic patterns. The model to forecast more realistic toll road demand is very essential for estimating toll revenue, choice of optimal toll level & collecting location and establishing toll charge strategy. This paper reviewed some literatures about toll road modelling and tested case study about the assignment technique with different VOT. The case study shows that using different VOT yields more realistic result than the use of single VOT.

• Korea Trade Review
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• v.42 no.1
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• pp.27-45
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• 2017

A new phenomenon in recent trade is the rising interest in the trade of product production and manufacturing methods themselves, unlike in the past, when the interest was focused on the trade of tangible goods. That is, technology is considered as the object of trade instead of a simple element of production as "technology itself is commercialized". The broad meaning of technology encompasses all the property of knowledge with economic value. Its narrow meaning refers to technology used to produce and manufacture goods. Technologies have features such as no forms, heterogeneity, accumulation of value and extinction of right. The trade of technology commands different styles and content from that of tangible goods due to their unique characteristics; and accordingly, has various risk factors. In other words, technology can be traded in various ways according to commercial objectives including licensing, technical partnership, and joint investment in addition to general trading. The specific forms of technology transfer strategies depend on the purposes and situations between corporations. In case of technical trade with any form, the parties should be cautious about the following practical aspects: First, the contract should clearly define the scope and transfer method of technology. It is a very important matter how the provider of technology will provide the user of technology with abstract technology with no substantiality. Second, a monopoly on technology recognized as intellectual property rights is granted to their inventors for some periods of time, but anyone can have access to that technology after the term of existence. Thus, it is important to check the terms of existence of a patent as well as the terms of contract. Third, the user of technology should fulfill his confidentiality obligation to prevent the technology of the provider from being leaked to a third party unjustly. Fourth, the provider of technology should make a contribution to the successful implementation of the technology by the user as well as provide the licensed technology. Finally, a model contract is recommended to minimizing the legal hiatus of complex technology transfer trade when concluding a contract.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7795-7801
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• 2015

The aim of the present research was to establish primary characteristics of electron beams for a Varian 2100C/D linear accelerator with recently developed PRIMO Monte Carlo software and to verify relations between electron energy and dose distribution. To maintain conformity of simulated and measured dose curves within 1%/1mm, mean energy, Full Width at Half Maximum (FWHM) of energy and focal spot FWHM of initial beam were changed iteratively. Mean and most probable energies were extracted from validated phase spaces and compared with related empirical equation results. To explain the importance of correct estimation of primary energy on a clinical case, computed tomography images of a thorax phantom were imported in PRIMO. Dose distributions and dose volume histogram (DVH) curves were compared between validated and artificial cases with overestimated energy. Initial mean energies were obtained of 6.68, 9.73, 13.2 and 16.4 MeV for 6, 9, 12 and 15 nominal energies, respectively. Energy FWHM reduced with increase in energy. Three mm focal spot FWHM for 9 MeV and 4 mm for other energies made proper matches of simulated and measured profiles. In addition, the maximum difference of calculated mean electrons energy at the phantom surface with empirical equation was 2.2 percent. Finally, clear differences in DVH curves of validated and artificial energy were observed as heterogeneity indexes were 0.15 for 7.21 MeV and 0.25 for 6.68 MeV. The Monte Carlo model presented in PRIMO for Varian 2100 CD was precisely validated. IAEA polynomial equations estimated mean energy more accurately than a known linear one. Small displacement of R50 changed DVH curves and homogeneity indexes. PRIMO is a user-friendly software which has suitable capabilities to calculate dose distribution in water phantoms or computerized tomographic volumes accurately.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.453-470
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• 2013

In this paper, we consider a Bayesian analysis of the dose-effect relationship of cadmium to evaluate a benchmark dose(BMD). For this purpose, two dose-response curves commonly used in the toxicity study are fitted based on Bayesian methods to the data collected from the scientific literature on cadmium toxicity. Specifically, Bayesian meta-analysis and hierarchical modeling build an overall dose-effect relationship that use a piecewise linear model and Hill model, where the inter-study heterogeneity and inter-individual variability of dose and effect such as gender, age and ethnicity are accounted. Estimation of the unknown parameters is made by using a Markov chain Monte Carlo algorithm based user-friendly software WinBUGS. Benchmark dose estimates are evaluated for various cut-offs and compared with different tested subpopulations with with gender, age and ethnicity based on these two Bayesian hierarchical models.

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.415-426
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• 2006

Many technical and nontechnical issues hinder enterprise wide workflow management. The most significant technical issue is the inability to deal with the heterogeneity among users, workflow types, and WFMSs. Not all users demand the same workflow functionality, so user interfaces of different levels of sophistication are required. Because workflow types cannot always be fully predefined, they often need to be adjusted or extended during execution. Unlike relational database management systems, however, each WFMS often has differing workflow metamodels. This leads to incompatibility between WFMSs, making integration into an environment comprising many heterogeneous WFMSs a troublesome and sometimes impossible task. Current Workflow system consists mainly of Database system. It contains some problems like that the integration relationship among system processes cant be expressed properly. This research has been focused on two phases that should be considered in the Workflow system. First of all, the first phase is the analysis phase; one of its role is to figure out independent execution task unit(Workflow component). The second phase is design phase that provides with the framework to execute these task units actively. The Workflow component extraction method in the analysis phase uses a analysis method called C-C Net and, in the design phase, the architecture that makes the these Workflow component executed actively is provided. Through this research, each process is divided into a task unit and more effective Workflow system could be formed by executing these units actively. Current system layer calls task units, on the other hand, the Workflow system this research implemented provides with the architecture that places a layer between them that controls task units actively.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.27-34
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• 2006

In the near future, people will wish to access many kinds of heterogeneous networks to use their services anytime and anywhere. Owing to the heterogeneity of networks, there must be many kinds of protocols to guarantee secure services. The mobile device can depend in a middleware for accessing services in the heterogeneous networks and the middleware helps the mobile device to communicate with services without blowing concrete protocols. If a secure channel is necessary, the middleware may access a private key in the mobile device to perform a security protocol. In this paper, we focus on the security of a private key in the mobile device against malicious middlewares. To do so, we introduce two models for a user to protect his/her private key against malicious middlewares by generating authentication data(e.g., digital signatures) without keeping the private key in the mobile device.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.163-170
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• 2021

As a big data is being used in various industries, big data market is expanding from hardware to infrastructure software to service software. Especially it is expanding into a huge platform market that provides applications for holistic and intuitive visualizations such as big data meaning interpretation understandability, and analysis results. Demand for big data extraction and analysis using social media such as SNS is very active not only for companies but also for individuals. However despite such high demand for the collection and analysis of social media data for user trend analysis and marketing, there is a lack of research to address the difficulty of dynamic interlocking and the complexity of building and operating software platforms due to the heterogeneity of various social media service interfaces. In this paper, we propose a method for developing a framework to operate the process from collection to extraction and classification of social media data. The proposed framework solves the problem of heterogeneous social media data collection channels through adapter patterns, and improves the accuracy of social topic extraction and classification through semantic association-based extraction techniques and topic association-based classification techniques.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.61-70
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• 2008

The study proposed a new type of bus information, Real-time Bus Crowdedness (RBC) information, to meet various demands of users and improve the convenience level of using public transportation, while existing bus information provided by bus information systems(BIS) were limited to bus operating information such as predicted bus arrival time. To analyze the impacts of providing the proposed RBC information, stated preference(SP) survey was performed and a methodology of disaggregate analysis (e.g., binary logit) was applied to develop passenger choice models. Additionally, passenger choice models incorporating the heterogeneity of different user groups(i.e., by age or trip purposes) were developed to evaluate the different responses on RBC information. The results showed that providing RBC information was significantly related to users' bus choices and the responses of user groups were significantly different, especially the age group of more then 60 was most affected by the RBC information on their bus choices. Also trip purposes were significantly related to users' bus choices, for instance the impacts of providing RBC information was bigger for non-business trips(leisure/meet friend/personal business, shopping, hospital) compared to business trip.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.296-305
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• 2006

The heterogeneity of crop transpiration is important to clearly understand the microclimate mechanisms and to efficiently handle the water resource in greenhouses. A computational fluid dynamic program (Fluent CFD version 6.2) was developed to study the internal climate and crop transpiration distributions of greenhouses. Additionally, the global solar radiation model and a crop heat exchange model were programmed together. Those models programmed using $C^{++}$ software were connected to the CFD main module using the user define function (UDF) technology. For the developed CFD validity, a field experiment was conducted at a $17{\times}6 m^2$ plastic-covered mechanically ventilated single-span greenhouse located at Pusan in Korea. The CFD internal distributions of air temperature, relative humidity, and air velocity at 1m height were validated against the experimental results. The CFD computed results were in close agreement with the measured distributions of the air temperature, relative humidity, and air velocity along the greenhouse. The averaged errors of their CFD computed results were 2.2%,2.1%, and 7.7%, respectively.

• Journal of KIISE:Software and Applications
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• v.28 no.2
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• pp.179-191
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• 2001

Comparison shopping is a merchant brokering process that finds the best price for the desired product from several Web-based online stores. To get a scalable comparison shopper, we need an agent that automatically constructs a simple information extraction procedure, called a wrapper, for each semi-structured store. Automatic construction of wrappers for HTML-based Web stores is difficult because HTML only defines how information is to be displayed, not what it means, and different stores employ different ways of manipulating customer queries and different presentation formats for displaying product descriptions. Wrapper induction has been suggested as a promising strategy for overcoming this heterogeneity. However, previous scalable comparison-shoppers such as ShopBot rely on a strong bias in the product descriptions, and as a result, many stores that do not confirm to this bias were unable to be recognized. This paper proposes a more scalable comparison-shopping agent named MORPHEUS. MORPHEUS presents a simple but robust inductive learning algorithm that antomatically constructs wrappers. The main idea of the proposed algorithm is to recognize the position and the structure of a product description unit by finding the most frequent pattern from the sequence of logical line information in output HTML pages. MORPHEUS successfully constructs correct wtappers for most stores by weakening a bias assumed in previous systems. It also tolerates some noises that might be present in production descriptions such as missing attributes. MORPHEUS generates the wrappers rapidly by excluding the pre-processing phase of removing redundant fragments in a page such as a header, a tailer, and advertisements. Eventually, MORPHEUS provides a framework from which a customized comparison-shopping agent can be organized for a user by facilitating the dynamic addition of new stores.