• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.144-153
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• 2012

This study investigates whether the use of N-screen service affects the use of Home TV service as a supplement or substitution. In this study, we collected 132 available survey answers from CJ Hellovision Tving users. We found supplement relationship between Tving and Home TV, which implies that the more use in Tving service, the use of Home TV increases as much as 36.4%. From the result, some meaningful implications were derived. First, a direction for content price negotiation between N-screen providers and terrestrial broadcasters can be suggested. Second, the result will provide a suggestion for establishing a competitive strategy between N-screen providers and Pay-TV providers. Third, this study may solve copyright dispute between content providers and pay TV operators.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.344-357
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• 2015

With the increase in a number of access technologies and data rates, a continuous connection among different networks is demand of the future wireless networks. In the last decade, user connectivity among different access networks remained a challenging job. Therefore, in this article, we proposed a user-centric and user-perspective based network selection mechanism for fast handover management in heterogeneous wireless networks. The proposed scheme selects the most appropriate network among available networks on the basis of resources i.e. cost, data rate, and link quality. Initially, we load the Media Independent Information Service (MIIS) with the information of cost and data rate provided by different network operators. Similarly, Mobile Node (MN) is also loaded with the user preferred cost and data rate for different applications. The MN obtains the information of cost and data rate from MIIS server upon a predefined threshold, and make a decision for handover according to its current cost and data rate. Furthermore, we employ an optimal threshold mechanism for initiation of the handover execution phase to minimize false handover indications. The proposed scheme is based on a survey for network selection and its implementation in C programming language to validate its performance and accuracy. The simulation result shows that the proposed scheme performs superior then the schemes present in the current literature.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.61-67
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• 2018

This study covers the results obtained after three years of development work of real - time gas safety monitoring app. In order to reduce the risk of accidents in the gas workplace, it is essential to provide information so that operators can recognize the location of dangerous substances, dangerous facilities, safety procedures, and the temperature and humidity of the workplace. Therefore, this study was conducted to develop a monitoring app that allows the main system to efficiently receive the information in the field where the information is continuously updated. As a result of quantitative and qualitative research and analysis on app scenarios based on the research done in the past and web screen of the main system, it was modified and improved in terms of ease of use, readability, and intuitiveness. Especially, we made many improvements at low depth, which is a sub-area of ease of use. As a result of conducting a user satisfaction survey on the finally derived app scenarios, the average score of 98.5 was obtained in terms of functionality, convenience and readability.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.103-108
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• 2018

Since tower cranes are susceptible to wind loads, the operation of the tower crane should be ceased when it exposed to a strong wind. For this reason, even in Korea, the operation limit for wind loading on the tower crane is regulated by a law. Recently the Korean law in which provided the wind speed limit to cease the tower crane operation has been revised from "instantaneous wind speed of 20 m/s" to "instantaneous wind speed of 15 m/s". Although this revision is expected to reduce safety risks in tower crane operation, some field operators still insist to lower the wind speed limit. However, in many countries "wind speed of 20 m/s" is normally used as the maximum in-service wind speed for tower cranes. Therefore, the investigation of the proper wind speed for regulation would be helpful to secure the safety of the tower crane operation under windy condition. In this study the validity of the revised wind speed limit is investigated with the surveys targeted to both tower crane practitioners and parties of concerned in construction companies, in which various questions was provided for a suitable wind speed limit and the answers were analyzed. The results showed that the revised wind speed limit is acceptable to tower crane practitioners as well as the parties of concerned in construction companies and is satisfying the structural stability requirement for in-service state tower crane. Therefore, it can be concluded that the revised wind speed limit is valid in humanly safety point of view.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.735-742
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• 2009

Information security is an essential factor that enables terminal to be operated. However, despite of this importance of information security, there has hardly been any research related to this topic. And moreover, current level of information security performance in container terminals has not been analyzed so far. The objective of this study is to evaluate current level of information security in container terminals. Through survey from the four leading container terminal operators in Korea, The results firstly showed that average of information security level of major container terminals was 71.7%. And from the results of data analysis, it revealed that the weak point of information security in Korean container terminals was security management, and in detail, lack of expertise of support group.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.211-215
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• 2017

The market of the municipal wasetewater treatment plant (MWTP) operation is expanding across the world including Korea. The contracting-out system was introduced for the effective operation of MWTPs. However, an improvement of the contracting-out system of MWTP has been continuously required. This research investigated current operational status of MWTPs in Korea, to suggest the improvement of the cost effective MWTP operation to promote the contracting-out system of MWTP operation. Results showed that lower operational costs of MWTP were lower in larger MWTPs than in smaller MWTPs. Overall, MWTPs operated by a public enterprise showed lower operational costs than those operated by government agencies and private enterprises. Among the MWTPs similar in their treatment capacity, treatment process and operation period, MWTPs operated by private enterprises showed the lowest operational cost. According to the survey, managers and operators of MWTPs emphasized the importance of improvement on the methods of selecting operating agencies and estimating operationing costs. The results of this study should be useful as important supporting data to promote the contracting-out system for the MWTP operation.

• Journal of Biosystems Engineering
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• v.37 no.6
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• pp.434-438
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• 2012

Purpose: This study was performed in order to improve problems and to seek the efficient operating plan by surveying and analyzing the actual status of operating the agricultural machinery rental business supported by the government. Method: The data was collected through two times of survey targeting lease business operators and the leasing business reports published for the past 3 years ('08~'10) 120 cities and counties. Results: As a result of surveying 120 cities and counties nationwide of operating the agricultural machinery rental business, 96% of agricultural machinery rental businesses were indicated to be operated in the form of short-term rent for about 1~3 days centering on small-sized agricultural machinery and attachment for upland crop. As for the unit number of possessing rental agricultural machinery and the purchase cost, it was indicated to be greatly reduced the agricultural machinery for rice farming and to be expanded into upland crop whose mechanization is insufficient. The annual rental days ('10) are 9.5 days/unit, thereby being a little insufficient. Rental fee for 1 day is 0.2~0.8% of the initial purchase cost of agricultural machine, thereby being greatly lower compared to 2.0% (annually 10-day rent) of the proper rents, resulting in being demanded improvement. Conclusions: To be continuously driven the rental business of agricultural machinery with having the ability to propagate, it is judged to be likely to necessarily collect optimum rental fee in consideration of rental days as well as increasing the use days per unit by buying the agricultural machinery, which is secured the rental demand, and by possessing the reasonable unit number.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1031-1042
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• 2009

Due to liberalization in the early stage, mobile communications market has grown rapidly in the world. However, some dominant operators set higher termination call charges, and thus the market has been distorted and customer welfare has been reduced a lot. The regulation of mobile termination charges is one of key issues of most regulatory agencies in the world. According to the survey, the level of mobile termination charges are quite different from country to country. Why is it so different? This paper investigated the determinants affecting the mobile termination charges for 28 countries by considering country-specific, industry-specific, and regulatory-specific conditions. We found that some regulatory-specific conditions are the most important factors. The rate of pre-paid contract and period of regulation mostly affect the mobile termination charges.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.270-277
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• 2015

In some sections of the Seoul Metropolitan Subway, severe congestion can be observed during rush hours and on specific days. The subway operators have been conducting regular surveys to measure the level of congestion on trains: the results are then used to make plans for congestion reduction. However, the survey has so far focused just on train' congestion and has been unable to determine non-recurring congestion due to special events. This study develops an algorithm to estimate the platform congestion rate by time using individual public transportation card data. The algorithm is evaluated by comparison of the estimated congestion rate and the ground truth data that are actually observed at non-transfer subway stations on Seoul subway line 2. The error rates are within ${pm}2%$ and the performance of the algorithm is fairly good. However, varying walking times from gates to platforms, which are applied to both non-peak periods and peak time periods, are needed to improve the algorithm.

• Korean Journal of Community Nutrition
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• v.11 no.5
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• pp.618-628
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• 2006

The purpose of this study was to examine the donators' characteristics and donative foods of both government-dominant and non-governmental food bank program, to understand the problems and benefits of food bank program, and to find the solutions to activate food bank program. The questionnaires were distributed to 120 food bank operators and 3 donators were selected from each food bank for the survey from April 2002 to May 2002. 118 sheets (32.8%) from government-dominant food bank and 53 sheets (20.1%) from non-governmental food bank were collected. The main results of this study were as follows: The largest donators to either government-dominant or non-governmental food bank programs were bakery and confectionery companies 31.4% and 45.3% respectively. The majority of donated foods were 'goods in stock' (55.6%) and frequency of donation were largely on a daily basis (27.1% for government-dominant and 22.6% for non-governmental). Some of the donators who had more donative food did not donate, and the reasons were closeness to expiration date of food (67.3%), lack of legal protection in the event of food poisoning (54.5%), and poor public image of food related accidents (52.3%).