• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.3
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• pp.262-276
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• 2016

Generally, the Safety Integrity Level (SIL) of a subsea Blowout Preventer (BOP) is evaluated by determining the Probability of Failure on Demand (PFD), a low demand mode evaluation indicator. However, some SIL results are above the PFD's effective area despite the subsea BOP's demand rate being within the PFD's effective range. Determining a Hazardous Event Frequency (HEF) that can cover all demand rates could be useful when establishing the effective BOP SIL. This study focused on subsea BOP functions that follow guideline 070 of the Norwegian Oil and Gas. Events that control subsea well kicks are defined. The HEF of each BOP function is analyzed and compared with the PFD by investigating the frequency for each event and the demand rate for the components. In addition, risk control options related to PFD and HEF improvements are compared, and the effectiveness of HEF as a SIL verification for subsea BOP is assessed.

• Advances in concrete construction
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• v.9 no.4
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• pp.337-343
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• 2020

In the present study, by employing fragility analysis, the seismic vulnerability of a concrete girder bridge, one of the most common existing structural bridge systems, has been performed. To this end, drift demand model as a fundamental ingredient of any probabilistic decision-making analyses is initially developed in terms of the two most common intensity measures, i.e., PGA and Sa (T₁). Developing a probabilistic demand model requires a reliable database that is established in this paper by performing incremental dynamic analysis (IDA) under a set of 20 ground motion records. Next, by employing Bayesian statistical inference drift demand models are developed based on pre-collapse data obtained from IDA. Then, the accuracy and reasonability of the developed models are investigated by plotting diagnosis graphs. This graphical analysis demonstrates probabilistic demand model developed in terms of PGA is more reliable. Afterward, fragility curves according to PGA based-demand model are developed.

• KNOM Review
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• v.21 no.2
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• pp.1-9
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• 2018

Network virtualization refers to a technology creating independent virtual network environment on a physical network. Network virtualization technology can share the physical network resources to reduce the cost of establishing the network for each user and enables the network administrator to dynamically change the network configuration according to the purpose. Although the network management can be handled dynamically, the management is manual, and it does not maximize the profit of network virtualization. In this paper, we propose Machine-Learning technology to allow the network to learn by itself and manage its management dynamically. The proposed approach is to dynamically allocate appropriate resources by predicting resource demand of VNF in service function chaining, which is a core and essential problem in virtual network management. Our goal is to predict the resource demand of the VNF and dynamically allocate the appropriate resources to reduce the cost of network operation while preventing service interruption.

• Environmental and Resource Economics Review
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• v.31 no.1
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• pp.31-50
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• 2022

This paper estimates the price of standard waste bags that satisfies the polluter pays principle. Unlike previous studies, this paper suggests a method that can find new equilibrium prices using a structural relationship between the demand and cost function for the wastes. To do this, we employ the fixed-point iteration. The main findings of this paper are as follows. Assuming that the polluter pays principle is achieved at the average cost for the waste treatment, the price need to be set at a level about 3.12 times higher than the current one. The estimation result using a structural model, however, shows that the price should be set at a level four times higher than the present. This results are because the quantities reduced of the wastes make the cost per quantity of wastes due to the fixed costs increase. If applying the estimated price to the demand function, the amount of discharge of waste generated nationwide can be reduced by 10%.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.2
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• pp.29-37
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• 2008

The purpose of this study was to analyze the customer demand for design development of digital convergence furniture in the living space of the ubiquitous home. This study used the individual survey method and was collected from July 1 to 20, 2008. The frequency and percentage were used for data analysis by SPSS window's 12. The results of the study were as follows: The first, a lot of survey targets were 30-40 years old, university graduates, over 50,000,000 won in annual income and 30-40 pyung in house size. The second, what types of activity were carried out in the living room were acquisition of knowledge>entertainment activity>communication activity>household chores. The third, what types of furniture were used in the living room were A/V furniture>table>sofa>computer table>bookself. The forth, customers preferred to picture telephone service in sociality, home-theater service in entertainment and home appliances remote control service in information service. The fifth, the digital functions which can integrate with the living roon furniture, in the item for A/V furniture, was front door control function which recognizes visitors with the screen. In the item for table was function to search internet and for sofa was self purification function. Finally, the digital convergence furniture is not only for one activity but also for various types of activities that can comprehensively function to materialize the concept of comfortable furniture in the living space.

• Journal of the Korean Regional Science Association
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• v.34 no.1
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• pp.49-60
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• 2018

The purpose of the study is to analyze the housing problems of single-person household in 20-35 age group. Using the survey of Household's Consumption in 2014, we estimated the housing demand function of young single-person household in Seoul. As a result, the coefficient of the permanent income for young single-person household housing was significantly lower than other groups and the housing demand was also lower than others. Since current income isn't come up to permanent income enough, the housing consumption of young single-person household shrinks. It implies the role of the housing financial market is less activated. That is, the difficulty of realization of permanent income and lack of housing finance are the main cause of the imbalance of housing demand of one young person. Therefore, it implies that in order to alleviate the housing problem of the young single-person household, a policy to balance the permanent income with the housing demand is needed.

• School Mathematics
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• v.14 no.2
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• pp.213-232
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• 2012

The purpose of this study was to examine and analyze the cognitive demand of the mathematical tasks suggested in the middle school textbooks. In particular, it aimed to reveal the overall picture of the level of cognitive demand of the mathematical tasks on function in the textbooks. We adopted the framework for mathematical task analysis suggested by Stein & Smith (1998) and analyzed the mathematical tasks accordingly. The findings from the analysis showed that 95 percent of the mathematical tasks were at low level and the rest at high level in terms of cognitive demand. Most of the mathematical tasks in the textbooks were algorithmic and focused on producing correct answers by using procedures. In particular, the high level tasks were presented at the end of each chapter or unit for wrap up rather than as key resources.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.53-73
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• 2003

This paper is to analyze the past and present consumption pattern of fishes aquacultured in marine waters and thus to draw the policy direction to enhance the competitiveness of marine fish aquaculture in Korea. At present, the volume of meat consumption is surveyed to be more than that of marine fish, but it is revealed that fish consumption will become more increasing in the future according to the rise of the income. The survey shows that the consumption of fish is highest in the fall, and among the various patterns of consumption, live fish, so-called susi, is surveyed to be highly dominant. It is revealed that fish is enjoyed because of the special savor, diverse nutrients, and the prevention of adult diseases. Natural fish Is revealed to be more preferred to aquacultured one due to the sticky flesh quality and the low probability of the remained after the production process antibiotics, so that it is necessary to enhance the taste quality and make a clean cultivation to capture more market demand. Consumption of high-quality fish seems to become high in more than middle class and consumption of fish are estimated to increase in the future, more than that of meat if income level of the people increases. Also, if we try to make our high-quality fish become popular among the public and competible with the imported fish from abroad, it is recommended that they must lower production price by cost reduction and try to differentiate it by taste and environmental safety, etc. It was revealed that the significant factor in demand function for fish is income and it is almost the only factor affecting that demand. Also, it was revealed that the most significant factor affecting preference of fish is income and it Is almost the only factor affecting the preference. Therefore, we can ascertain that if proper goods can be distributed, demand for and preference of fish may increase according to the increase of income in the future.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.552-555
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• 2001

In this paper, an intelligent demand control system was introduced. This system are composed of demand controller, RTU, power line modem and HMI program. The proposed demand controller was capable of synchronizing with watt-hour meter recommended by KEPCO(Korea Electrical Power Corporation). To control remote loads, network function using powerline communication is implemented in RTU with HMI program and novices are able to operate system easily. Additionally using the power line, the cost and time of installation can b saved. The system performance was proved with a several experiments.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.324-327
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• 1996

In this paper, the affecting factors of the access demand for the cellular service are derived, and the access demand function of the cellular service is estimated. The results obtained in this study are as follows: First, the price (access charge) and the income elasticities of cellular services there exists a network externality in cellular communication services. Third, the technological capability of the service provider has played an essential role in expanding the size of subscribers. Fourth, the access demand of cellular communication service is not sensitive to the usage charge. According to the above results, it can be inferred that if the access charge is lowered, the number if subscribers will increase to the critical mass, and then the cellular communication market will grow up to a saturation point naturally.