• International Journal of Aeronautical and Space Sciences
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• v.5 no.2
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• pp.54-61
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• 2004

In this paper we carried out a design study for an unmanned Mars missionsuitable for Republic of Korea. The mission will use a KSLV series launch system,which is to place a one tonne payload into the LEO. We calculated the velocityincrements(AV) required for departure from Earth and insertion into the orbitaround Mars based on the mission opportunity data provided by NASA. Two typesof Mars modules - entry type and orbiter type - were considered in this studyWe calculated the mass of TPS(therma1 protection system) for the entry tvpe Marsmodule based on the heat transfer rate and heat load from the Mars atmosphere tothe surface of the TPS. The heat transfer rate and heat load were obtained throughan entry trajectory calculation. For the orbiter type Mars module, we calcuIated themass breakdown of the additional spacecraft which is to insert the Mars moduleinto the orbit around Mars. Other mass items were determined by proportioningfrom the existing Mars modules. This paper finally proposes the payload capacitiesfor each types of Mars modules.

• Geomechanics and Engineering
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• v.10 no.2
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• pp.225-245
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• 2016

Settlement of foundations in permafrost regions primarily results from three physical and mechanical processes such as thaw consolidation of permafrost layer, creep of warm frozen soils and the additional deformation of seasonal active layer induced by freeze-thaw cycling. This paper firstly establishes theoretical models for the three sources of settlement including a statistical damage model for soils which experience cyclic freeze-thaw, a large strain thaw consolidation theory incorporating a modified Richards' equation and a Drucker-Prager yield criterion, as well as a simple rheological element based creep model for frozen soils. A novel numerical method was proposed for live computation of thaw consolidation, creep and freeze-thaw cycling in corresponding domains which vary with heat budget in frozen ground. It was then numerically implemented in the FISH language on the FLAC platform and verified by freeze-thaw tests on sandy clay. Results indicate that the calculated results agree well with the measured data. Finally a model test carried out on a half embankment in laboratory was modeled.

• Korean Journal of Clinical Pharmacy
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• v.28 no.2
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• pp.124-130
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• 2018

Objective: This study examined the Risk Sharing Agreement (RSA) on pharmaceutical pricing system in Korean national health insurance. Through RSA, the insurer was able to maintain the principles in the price listing process while managing the budget effectively and improving patient access to new drugs. Despite these positive effects, there are still issues raised by some stakeholders, such as lack of transparency in the listing process and doubts about its effectiveness. Therefore, we investigated the impacts of RSA on national health insurance financing and patient access to analyze the effects of RSA. Methods: The impact of RSA was investigated by analyzing the health insurance claims data for 2014~2016. The degree of improvement in patient access was determined by the decreased amount of patients' payment. Results: Results showed that the financial impact of RSA was not significant and patients' access to the new drug greatly improved. Conclusion: These results show that RSA is a good system for improving patient access to new drugs without additional expense on insurance.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.677-694
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• 2009

While the budget has been allocated more for repairs and reinforcements, casualties are gradually increased due to slope disaster. Slope disaster causes road damaged as well as casualties. It also causes significant social and economic loss. The measurement device, which is installed inside ground of slope like inclinometer, has the high loss rate when slope is being slided. The electric type and the vibrating wire type have low durability because of corrosion. To cover the demerit of the present slope monitoring, the measurement method using the Multi-Antenna GPS has been developed. The Multi-Antenna GPS has been installed in the local slope as the regular monitoring system for slope. Although the initial cost of the Multi-Antenna GPS for installation is high, the additional cost is low. So it is the suitable method for large slope. The regular monitoring system using the Multi-Antenna GPS is the suitable measurement method for watching slope collapse, which is occurred widely, because it is economical, has high durability, and collects data with high resolution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1306-1312
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• 2000

The quality loss of a X-band transmitter has been derived by means of MC simulation. The transmitter as a payload of LEO(Low Earth Orbit) satellite is capable of the down transmission the image data of hundreds Mbps generated from the Electro-Optical Instrument in real time. The parameters such as data asymmetry amplitude unbalance,phase unbalance, wave shaping and channel interference are included in the quality loss simulation Assuming that normally distributed gaussian noise is simply added to the channel, the quality loss of 0.7 dB has been obtained through this simulation based on a 95% confidence interval. The obtained quality loss can be applied to the link budgets as an additional loss item.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2051-2057
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• 2008

This paper is a feasibility study on the calculation of operating cost in regards to the overall operation following the completion of a number of LRT lines currently in progress. Owing to the absence of operating experience in driveless LRT system at home, the difficulties lie in the assumption of the optimal operating budget applying domestic real situation. Nevertheless, with 34 years of accumulated operating experience in heavy rail transit system, Seoul Metro, the nation's biggest urban rail transit operator, performs O&M consultancy services for several on-going projects along with every effort to acquire know-how where the appropriateness of the cost estimation as a required deliverable is reviewed and a more efficient way is provided. The main focus of this study is to seek a method to calculate the optimal amount of operating expenses as well as a cost-effective alternative for possible weaknesses from the standpoint of the operator. The body of this paper discusses the five issues such as personnel cost, overhead, maintenance cost, additional purchase price, alternative investment fee from a more macroscopic point of view, and the conclusion deals with the adequacy of the reason for selection of institutions with various operating know-how.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.609-620
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• 2017

We studied the value of a nuclear power plant by considering Koreans' willingness to pay (WTP) for neutralizing the various problems caused by building and operating a new plant. For this, we used a conjoint analysis and ordered logistic regression. We then compared the WTP estimates between various segment groups. The results revealed that each household was willing to pay an additional 99,677 Korean Won (KRW)/mo on average to resolve the negative impacts from a nuclear plant. Therefore, the yearly cognitive and economic value of a nuclear plant in Korea was about 19 trillion KRW. Through a segment analysis, we found that the more educated, younger, and poorer groups gave higher cognitive values than the less educated, older, and richer groups, respectively. Also, people who lived far from a plant gave higher values than people living near a plant, and people with more knowledge about or interest in nuclear energy gave higher values than people with less knowledge or interest. People who felt that nuclear energy is necessary gave higher values to nuclear energy than those who did not. Our results can be used as bases to set targets for promoting nuclear energy and pursuing a national project of building a nuclear power plant.

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.45-49
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• 2018

Portable microcontroller based measurement unit is demonstrated using digital-to-analog convertor module, analog-to-digital convertor module and additional preamplifier circuit with low-budget but excellent performances. Using the designed measurement unit, the measurement of current below 1 nA with applying voltage up to 5 V is successfully carried out. With the WiFi module in microcontroller, measured data is transferred to the user's computer. To evaluate the performance of the measurement unit, the transfer curve of a commercial N-type field effect transistor was measured with the measurement unit and the results is well consistent with that measured using commercial characterization system.

• Korean Journal of Artificial Intelligence
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• v.10 no.1
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• pp.9-14
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• 2022

The demand for public bicycles operated by the Seoul Metropolitan Government is increasing every year. The size of the Seoul public bicycle project, which first started with about 5,600 units, increased to 3,7500 units as of September 2021, and the number of members is also increasing every year. However, as the size of the project grows, excessive budget spending and deficit problems are emerging for public bicycle projects, and new bicycles, rental office costs, and bicycle maintenance costs are blamed for the deficit. In this paper, the Azure Machine Learning Studio program and the Boosted Decision Tree Regression technique are used to predict the number of public bicycle rental over environmental factors and time. Predicted results it was confirmed that the demand for public bicycles was high in the season except for winter, and the demand for public bicycles was the highest at 6 p.m. In addition, in this paper compare four additional regression algorithms in addition to the Boosted Decision Tree Regression algorithm to measure algorithm performance. The results showed high accuracy in the order of the First Boosted Decision Tree Regression Algorithm (0.878802), second Decision Forest Regression (0.838232), third Poison Regression (0.62699), and fourth Linear Regression (0.618773). Based on these predictions, it is expected that more public bicycles will be placed at rental stations near public transportation to meet the growing demand for commuting hours and that more bicycles will be placed in rental stations in summer than winter and the life of bicycles can be extended in winter.

• Health Policy and Management
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• v.33 no.2
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• pp.214-222
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• 2023

Refugees who are persecuted can apply for refugee recognition in the Republic of Korea in accordance with the Refugee Convention and the Refugee Act. They can do so either at the port of entry or during their stay in Korea. After undergoing screening, individuals may be recognized and protected under different categories, such as recognized refugees, humanitarian status holders, refugee applicants, and refugees seeking resettlement. Recognized refugees are entitled to the same social benefits and basic livelihood guarantees as Korean nationals. Humanitarian status holders and refugee applicants may receive support such as minimum living expenses, housing facilities, medical care, and education. In the medical field, refugees and their unmarried minor children are eligible for medical support through the "Medical Service Support Project for Marginalized Populations, Including Foreign Workers." This support is in addition to the national healthcare coverage and medical benefits provided by the government. However, there are pressing concerns regarding the inadequate budget allocated to this project and the excessive cost burden placed on participating medical institutions. It is crucial to secure additional funding and implement administrative improvements. Furthermore, it is essential to develop medical support measures that ensure the minimum right to health for individuals who choose not to undergo the refugee recognition process at the port of entry.