• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.549-556
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• 2020

Real estate markets play an essential role in the economic development of both developed and developing countries. Investment decisions in private real estate demand the consideration of several qualitative and quantitative criteria. Especially in Vietnam, demand for housing, apartments are rising which has resulted because of the migration from rural to urban areas. This study aims to determine the influencing factors of the real estate purchasing behavior and then recommend a grey Multi-Criteria Decision Making (MCDM) support model to evaluate real estate alternatives based on a numerical example in Vietnam. A set of essential criteria are identified based on experts' opinion, and the proposed determinants are initial investment, maintenance cost, prestige location, distance to interesting places, parking lot, public transportation, property condition, total area size, number of rooms, and neighbors. The subjective weights were obtained by using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) model, and the Grey Relational Analysis (GRA) technique is employed to prioritize and rank real estate alternatives. The results reveal that this approach can be useful to make purchasing decisions for many kinds of real estate property under uncertain business environments. These findings indicate that the presented hybrid model has advantages in granting flexibility to the preferences of decision makers.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.363-366
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• 2002

The advanced construction technology endorsement system(ACTES) has used the improper evaluation criteria. Because of its insufficiency of quantitative evaluation, it is difficult to attain the objective and fairness. This study used a survey to investigate a actual condition of ACTES. The survey found that ACTES needed a evaluation criteria and a quantitative evaluation method. In addition, This study proposes the evaluation model that uses a discriminant function. The model process consists of several phases that are brain storming, t-test and discriminant function analysis.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.589-594
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• 2011

Selecting an appropriate railway system in urban railway project is an important step for an efficient public transport policy. This paper attempts to solve the railway system selection problems in the (pre)feasibility study or preliminary research of urban railway project, by the rough transportation demand forecasting and financial analysis. There are two stages in this paper: in stage one, we review the worthwhile and various criteria which presented in precedent studies; whereas in stage two, an structured selection criteria is proposed for determining the appropriate railway system in urban railway project. The utilization of the proposed criteria is demonstrated with the case of a newtown in the metropolitan area. The results show that proposed criteria can be used to make the rational decision for governmental financial condition and social benefit.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.121-128
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• 2010

The purpose of this study is to confirm the impact of noise on subject accomplishment as well as physical/mental load, and evaluates the effects of noise-masking and earplug. 15 college students participate in the test, and the comparison is performed by executing four projects according to conditional categories of noise environments; control condition, noise condition, earplug condition, and noise-masking condition. Noise in the field site of the H manufacturer was used as the noise source, the general job aptitude test which consist of linguistic ability, math ability, perception ability, reasoning ability was used as the task of this project. To estimate physical/mental load evaluation, we used the heart rate R-R interval, Criteria flicker fusion frequency(CFF) and measured NASA-TLX workload for subjective evaluation. As the research outcome, it is shown that there is a meaningful difference for the project task score, dropping rate of CFF, the heart rate, and NASA-TLX subjective evaluation score according to conditions of noise environment. Therefore, the impact of noise on capability of subject accomplishment as well as physical/mental load was confirmed along with the effects of using earplug and noise-masking.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.7 no.1
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• pp.77-89
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• 1999

The atmosphere condition at Kimpo International Airport occasionally prevents the aircraft from landing and forces them to fly to an alternate airport, especially in October and November during a year. Many airlines designated foreign airports instead of Korean airports as alternate airports in the case of the bad weather condition preventing use of Kimpo Airport. This paper addresses 1) economic comparison of candidates for the alternate airport, 2) what are the criteria for the alternate airport selection and the relative importance among the criteria and 3) evaluation of candidates for alternate airport using Brown and Gibson's pair-wise comparison method. It is found to be possible to reduce costs related alternate flight by 36% using Korean airports rather than using Japan's Hukuoka Airport. However, airlines weigh more on the factors such as service level of ground handling, accommodation for passengers and ground access convenience than costs. Among Korean airports, Kimhae International Airport is found the most favorable airport as the alternate airport for Kimpo International Airport.

• Journal of the Korean Institute of Navigation
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• v.24 no.5
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• pp.373-383
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• 2000

The ship’s safe mooring stability is a principles for the safe cargo handling works at the mooring berth. Today numerous standards, guidelines and recommendations concerning mooring practices, fittings and equipments exist throughout the worldwide maritime industries. In recently, the mooring facilities were constructed as dolphin types at the open sea area apart far from shoreside instead of enclosed coastline area in accordance with increasing ship’s size and for preventing environmental pollution. Therefore the exciting wave condition must be considered as a basic environmental criteria with the wind force and current force for all of the mooring ships at the sea berth facilities. In this study, this added wave force as one of the environmental external forces by using the theoretical formula was applied to the LNG ship in Pyeongtaeg harbor needed the special mooring stability of the sea berth. Through this research, it can be confirmed that wave force is the very important factor in the mooring force and the strength of wave force works much more in the full laden condition than in the lightship condition. And also the wave force changes to non-linear states according to the wave frequency and wave length. In addition, the maximum limit criteria of environmental force of prohibiting the entering ship on the berth and loading works controlled by the port authority concerned of Pyeongtaeg port fully satisfies the condition of the mooring limit force recommended by OCIMF that the safe permitted force of the mooring line have to be within 55 % of MBL.

• Journal of Intelligence and Information Systems
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• v.22 no.3
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• pp.23-43
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• 2016

As a result of the growth of Internet data and the rapid development of Internet technology, "big data" analysis has gained prominence as a major approach for evaluating and mining enormous data for various purposes. Especially, in recent years, people tend to share their experiences related to their leisure activities while also reviewing others' inputs concerning their activities. Therefore, by referring to others' leisure activity-related experiences, they are able to gather information that might guarantee them better leisure activities in the future. This phenomenon has appeared throughout many aspects of leisure activities such as movies, traveling, accommodation, and dining. Apart from blogs and social networking sites, many other websites provide a wealth of information related to leisure activities. Most of these websites provide information of each product in various formats depending on different purposes and perspectives. Generally, most of the websites provide the average ratings and detailed reviews of users who actually used products/services, and these ratings and reviews can actually support the decision of potential customers in purchasing the same products/services. However, the existing websites offering information on leisure activities only provide the rating and review based on one stage of a set of evaluation criteria. Therefore, to identify the main issue for each evaluation criterion as well as the characteristics of specific elements comprising each criterion, users have to read a large number of reviews. In particular, as most of the users search for the characteristics of the detailed elements for one or more specific evaluation criteria based on their priorities, they must spend a great deal of time and effort to obtain the desired information by reading more reviews and understanding the contents of such reviews. Although some websites break down the evaluation criteria and direct the user to input their reviews according to different levels of criteria, there exist excessive amounts of input sections that make the whole process inconvenient for the users. Further, problems may arise if a user does not follow the instructions for the input sections or fill in the wrong input sections. Finally, treating the evaluation criteria breakdown as a realistic alternative is difficult, because identifying all the detailed criteria for each evaluation criterion is a challenging task. For example, if a review about a certain hotel has been written, people tend to only write one-stage reviews for various components such as accessibility, rooms, services, or food. These might be the reviews for most frequently asked questions, such as distance between the nearest subway station or condition of the bathroom, but they still lack detailed information for these questions. In addition, in case a breakdown of the evaluation criteria was provided along with various input sections, the user might only fill in the evaluation criterion for accessibility or fill in the wrong information such as information regarding rooms in the evaluation criteria for accessibility. Thus, the reliability of the segmented review will be greatly reduced. In this study, we propose an approach to overcome the limitations of the existing leisure activity information websites, namely, (1) the reliability of reviews for each evaluation criteria and (2) the difficulty of identifying the detailed contents that make up the evaluation criteria. In our proposed methodology, we first identify the review content and construct the lexicon for each evaluation criterion by using the terms that are frequently used for each criterion. Next, the sentences in the review documents containing the terms in the constructed lexicon are decomposed into review units, which are then reconstructed by using the evaluation criteria. Finally, the issues of the constructed review units by evaluation criteria are derived and the summary results are provided. Apart from the derived issues, the review units are also provided. Therefore, this approach aims to help users save on time and effort, because they will only be reading the relevant information they need for each evaluation criterion rather than go through the entire text of review. Our proposed methodology is based on the topic modeling, which is being actively used in text analysis. The review is decomposed into sentence units rather than considering the whole review as a document unit. After being decomposed into individual review units, the review units are reorganized according to each evaluation criterion and then used in the subsequent analysis. This work largely differs from the existing topic modeling-based studies. In this paper, we collected 423 reviews from hotel information websites and decomposed these reviews into 4,860 review units. We then reorganized the review units according to six different evaluation criteria. By applying these review units in our methodology, the analysis results can be introduced, and the utility of proposed methodology can be demonstrated.

• Structural Engineering and Mechanics
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• v.51 no.5
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• pp.707-725
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• 2014

In order to improve the crane-hook's performance and service life, we formulate a multi-criteria shape design problem considering practical conditions. The structural weight, the displacement at specified points and the induced matrix norm of stiffness matrix are adopted as the evaluation items to be minimized. The heights and widths of cross-section are chosen as the design variables. The design variables are expressed in terms of shape functions based on the Gaussian function. For this multi-objective optimization problem with three items, we utilize a multi-objective evolutionary algorithm, that is, the multi-objective Particle Swarm Optimization (MOPSO). As a common feature of obtained solutions, the side views are tapered shapes similar to those of actual crane-hook designs. The evaluation item values of the obtained designs demonstrate importance of the present optimization as well as the feasibility of the proposed optimal design approach.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.467-475
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• 2018

The purpose of this study is to propose the evaluation criteria of asphalt pavement condition in narrow regional road considering the traffic environment in order to reduce road budget of local governments. In general, narrow regional roads are considered relatively less important because they have low travel speed and low traffic volume of heavy-vehicle. Generally, automatic surveying equipment is used for investigations of pavement condition, but the operating costs are not efficient for the narrow regional roads because the cost is too high. This study presents the pavement condition evaluation index suitable for narrow regional roads. In this study, the pavement condition evaluation index is presented considering the traffic environment of narrow regional roads. The pavement condition were classified into three classes based on the crack measured by visual inspection, and the validity of the pavement condition evaluation index presented through the expert's questionnaire survey was examined. Pavement condition for the narrow regional roads was classified into three grades based on the index values calculated by visual inspection. Expert's surveys were conducted to evaluate the validity of the proposed pavement condition evaluation. The proposed evaluation index shows a high correlation with questionnaire survey result ($R^2=0.88$). The proposed evaluation index which is obtained through visual crack inspection under limited conditions can be applied to narrow regional roads. In addition, it is expected that it will be effective not only for road management but also for road management budget by more economical evaluation method of pavement condition.

• Journal of Korean Society on Water Environment
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• v.18 no.3
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• pp.327-336
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• 2002

Disinfection process in water treatment plants (WTPs) is one of the most important step in order to inactivate waterborne disease. However, what is the necessary disinfection in WTPs was not properly established in Korea. This study was conducted to evaluate disinfection performance in nationwide water treatment plants (n=474). Disinfection requirement based on the SWTR (Surface Water Treatment Rule) of the U.S. (1-log Giardia removal) was chosen in estimating the compliance. The scope of unit process for evaluating disinfection performance includes postdisinfection process in clearwells, pipeline, and storage tank. The worst water quality condition in individual WTPs was applied for the disinfection performance evaluation. The major results are as follows. First, it was appeared that 184 WTPs (39 %) provided insufficient disinfection performance. Disinfection performance was significantly improved during past 2 years. The ratio of the number of WTPs providing insufficient disinfection performance in 1999 and 2001 was 78 % and 41 %, respectively. One of major factors for this improvement was due to the improvement of $T_{10}/T$ value in clearwell, as a result of modification of clearwell facility. Second, if disinfection criteria is 3-log Giardia inactivation at worst water quality condition, then 19 % of all WTPs can not meet this disinfection criteria. And if disinfection criteria is strengthened to 4-log Giardia inactivation, then 58 % of all WTPs can not meet this disinfection criteria. Since disinfection criteria is decided by contamination level of Giardia in source water, it also needs the investigation of Giardia occurrence in source water.