• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.545-548
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• 2013

It has been shown that calculating atomic charges using quantum mechanical level theory greatly improves the accuracy of docking. A protocol was developed and shown to be effective. That this protocol works is just a manifestation of the fact that electrostatic interactions are important in protein-ligand binding. In order to investigate how the same protocol helps in prediction of binding affinities, we took a series of known cocrystal structures of influenza neuraminidase inhibitors with the receptor and performed docking with Glide SP, Glide XP, and QPLD, the last being a workflow that incorporates QM/MM calculations to replace the fixed atomic charges of force fields with quantum mechanically recalculated ones at a given docking pose, and predicted the binding affinities of each cocrystal. The correlation with experimental binding affinities considerably improved with QPLD compared to Glide SP/XP yielding $r^2$ = 0.83. The results suggest that for binding sites, such as that of neuraminidase, which are laden with hydrophilic residues, protocols such as QPLD which utilizes QM-based atomic charges can better predict the binding affinities.

• 한국안전학회지
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• 제17권4호
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• pp.101-109
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• 2002

The electrical properties of polyethylene are changed by the superstructure. Such crystalline polymer as polyethylene or polypropylene changes crystallinity and products spherulite or trans-crystal when it is cooled slowly. In this study, after thermal treatment of LDPE at 100[${circ}C$], in silicone oil for an hour, we made specimens in order of slow cooling, water cooling, quenching according to cooling speed. Also, to study the influence of electrical properties due to the superstructure change, we analyzed physical properties and performed dielectric breakdown experiments using DC and impulse voltage Moreover we measured space charges in bulk using Laser Induced Pressure Pulse(LIPP) method. Trap level of specimen is 0.064[eV] at the low temperature region 0.31[eV] at the high temperature region in DC dielectric strength, 0.03[eV] at the low temperature region 0.0925[eV] at the high temperature region in impulse dielectric strength. As its result shows that the quantity of charges induced from the electrode surface increases with applied voltage time, and the distribution of space charges in samples increases the quantity of charges in proportion to applied voltage.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.167-173
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• 2017

In this paper, the characterization of the vertical position of trapped charges in the charge-trap flash (CTF) memory is performed in the novel CTF memory cell with gate-all-around structure using technology computer-aided design (TCAD) simulation. In the CTF memories, injected charges are not stored in the conductive poly-crystalline silicon layer in the trapping layer such as silicon nitride. Thus, a reliable technique for exactly locating the trapped charges is required for making up an accurate macro-models for CTF memory cells. When a programming operation is performed initially, the injected charges are trapped near the interface between tunneling oxide and trapping nitride layers. However, as the program voltage gets higher and a larger threshold voltage shift is resulted, additional charges are trapped near the blocking oxide interface. Intrinsic properties of nitride including trap density and effective capture cross-sectional area substantially affect the position of charge centroid. By exactly locating the charge centroid from the charge distribution in programmed cells under various operation conditions, the relation between charge centroid and program operation condition is closely investigated.

• Journal of Preventive Medicine and Public Health
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• 제27권4호
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• pp.807-814
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• 1994

This study is to find out changes in medical practice at a university hospital before and after covering intraocular lens (IOL) from the health insurance benefit. The coverage started on March 1, 1993 and a total of 596 cases who were discharged from July 1 to December 31, 1992 and 580 cases who were discharged from July 1 to December 31, 1993 were analyzed. Since the standard reimbursement scheme was changed from March 1, 1993, the charges for 1992 were transformed into 1993 scheme. Major findings are as follows: Average length of stay was statistically significantly decreased from 8.24 days in 1992 to 6.86 days in 1993. Charges except IOL has been statistically significantly decreased from 501,000 Won in 1992 to 444,000 Won in 1993. Charges for drugs and injection have been reduced. However, charge per day for them was not much different. This is due to decrease in length of stay. Charges for laboratory tests and radiologic examination were quite the same. Charges which are not covered by the insurance remained the same. The revenue of the hospital was reduced as expected. However, the hospital reduced the length of stay and increase the turnover rate In order to compensate the potential loss of revenue due to the difference of reimbursement between the out-of-pocket expense and the insurance coverage. By introducing the IOL benefit in the insurance, the insured pays less, hospital generates more revenue through shortening the hospital stay, and the total medical care cost becomes less nationwidely.

• 통합자연과학논문집
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• 제3권4호
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• pp.226-230
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• 2010

Calculation of partial charge is important in chemistry. However, because there are many methods developed, it is of considerable interest to know how to calculate and apply properly to address various chemical problems. For basis set, usually double zeta quality is acceptable, and double zeta polarization function would be enough for most cases. To describe electronic state more accurately, Many electron configurations would be necessary to describe highly strained or anionic species. The NPA population introduced new concept about amide bonds, i.e., the planar geometry of nitrogen atom may not come from resonance, but from the lowering of p-orbital energy by electronegative carbonyl carbon atom. The issues for hypervalent atomic charges was also addressed by various charge derivation scheme. When the charge schemes were applied to organolithium compounds, the ionic nature of boding was revealed. This comes from the fact that previous Mulliken partial atomic charges overemphasized the covalent character, wihout much justification. The other partial charge derivation schemes such as NPA(natural population analysis), IPP (Integrated Projected Population) showed that much more ionic picture. ESP potential derived charges are generally believed to be suitable to describe intermolecular interactions, therefore they are used for molecular dynamics simulations and CoMFA (comparative molecular field analysis). The charge derivation schemes using multipole polarization was mainly applied to reproduce experimental infrared spectroscopy. In some reports these schemes are also suitable for intermecular electrostatic interactions. Charges derived from electron density gradient have shown the some bonds are not straight, but actually bent. The proper choice of charge-calculation method along with suitable level of theory and basis set are briefly discussed.

• 한국병원경영학회지
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• 제4권2호
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• pp.41-59
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• 1999

Objectives: This study was done to compare patient satisfaction and hospital charges of surgery performed in an outpatient basis(ambulatory surgical procedures). Methods : This retrospective study was performed in 20(vitrectomy 11, tonsillectomy 9) randomly selected ambulatory surgical procedures patients and 50(vitrectomy 26, tonsillectomy 24) inpatients who. received the same procedure at a general hospital in Seoul since January 1, 1998 to October 31, 1998. The operative procedures were vitrectomy and tonsilletomy which could be performed on a ambulatory surgical procedures basis or on an inpatient basis. Results: The results of this study shows that the patients thought the expenses and the surgical operative time was an important factor in a ambulatory surgical procedures but there were no differences in the patient satisfaction by the method of surgery. The charges of vitrectomy and tonsilletomy were reduced up to 495,000 won and 380,000 won from l,589,000 won 842,000 won inpatient surgery respectively. Conclusions: This study focused only on the charges of the surgical procedures and did not include the cost of patient helper, the lost salary due to missing days of work to care for a member of the family, transportation costs, and other indirect costs. Therefore, if those fees were included, ambulatory surgical procedures would be more economical. Therefore, by giving incentives at the fee schedule, the government health policies it would reduce the total hospital charges.

• 국제지역연구
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• 제18권3호
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• pp.249-265
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• 2014

지난 10년 동안 국제모바일로밍서비스가 제공되어 왔으나, 그 요금수준은 여전히 높은 수준에 있다. 이러한 국제모바일로밍서비스 요금수준에 대한 인식이 국제적으로 확산됨에 따라 국제기구 등에서는 로밍요금에 대한 다양한 개선방향 및 정책을 제시하고 있다. EU의 경우 로밍 이용요금 상한선 등에 대한 규제정책을 시행하고 있으며, OECD의 경우 강제적인 규제정책은 가지고 있지 않으나, 높은 로밍 요금 원인분석 및 이러한 요금에 대한 해결책의 회원국에 강구를 요구하고 있다. WTO는 서비스 무역 이사회를 중심으로 국제서비스무역을 저해하는지에 대한 검토를 하고 있으며, ITU에서도 요금에 대한 권고(D.98) 제시를 통하여 문제를 해결하려고 하고 있다. 본고의 목적은 국제모바일로밍서비스에 대한 주요 국제기구의 논의사항을 살펴보고 이를 통한 우리나라가 취할 수 있는 요금인하를 위한 규제정책방향을 제시하는 데 있다.

• 한국건설관리학회논문집
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• 제20권5호
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• pp.61-71
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• 2019

2018년 헌법개정을 통한 토지공개념 강화를 위한 개헌논란에서 보았듯이 토지와 관련된 정책문제는 지속으로 발생되고 있다. 본 연구에서는 토지공개념의 헌법적근거와 개발이익의 개념을 확인하고 헌법재판소의 판례를 통한 개발부담금 제도의 정당성을 조사한 후 개발부담금 산정의 공정성과 신뢰성 확보를 위한 개선방안을 제시하였다. 첫째, 개발부담금 제도의 투명성확보와 투기적 개발사업의 방지, 부과권자의 행정효율화를 위하여 개발부담금 추정시스템의 개발이 필요한 점과 둘째, 납부의무자가 제출하는 개발비용 산출명세서를 전문가에게 작성토록 제도화하여 부실산정을 방지하고, 셋째, 개발비용 산출을 위한 기초자료를 인 허가 시점부터 부관에 구체적으로 명시하거나 개발부담금 부과업무징수처리규정에 적시하여 제도화할 것을 제시하였다. 그리고 공사계획변경에 의한 설계변경시에도 첨부하도록 하여 준공후 개발비용 산정시 개발사업기간내 제출된 자료를 활용하도록 하여 개발비용의 신뢰도를 높이도록 제안하였다.

• 디지털융복합연구
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• 제17권9호
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• pp.39-46
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• 2019

본 연구는 인천공항의 비항공수익 비중이 과연 지나치게 높은 것인가라는 연구 질문에서 출발하게 되었다. 공항의 전통적 비즈니스 모델에 기반 한 항공수익은 여러 규제로 인해 성장의 한계를 가지고 있지만, 경쟁력 향상을 고민하는 공항운영주체들에 의해 비항공수익 증대에 대한 관심이 커지고 있다. 본 연구에서는 공항의 비항공수익이 공항사용료에 미치는 영향을 다루고 있으며, 공항산업의 핵심이슈 중 하나인 민영화 요인을 연구에 반영하였다. 또한, 인천공항 단일 사례가 아닌 전 세계 178개 공항을 대상으로 실증 분석하였다. 연구결과 국제공항의 비항공수익 비중이 높을수록 공항사용료는 낮아지는 것으로 나타났으며, 민간지분율은 비항공수익 비중과 공항사용료 간의 인과관계를 양(+)의 방향으로 조절하였다. 이는 공항의 민영화 추진이 상업 활동 증대를 통한 공항사용료 감소효과를 상쇄하는 결과를 초래할 수 있는 것으로 해석할 수 있다. 조절효과에 대한 가설검증은 그림으로 이해하기 쉽도록 도표로 제시하였다.

• 대한화학회지
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• 제56권2호
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• pp.195-200
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• 2012

In this study we present a new approach for computing the partial atomic charge derived from the wavefunctions of molecules. This charge, which we call the "y_charge", was calculated by taking into account the energy level and orbital populations in each molecular orbital (MO). The charge calculations were performed in the software, which was developed by us, developed using the C# programming language. Partial atomic charges cannot be calculated directly from quantum mechanics. According to a partitioning function, the electron density of constituent molecular atoms depends on the electrostatic attraction field of the nucleus. Taking into account the Boltzmann population of each MO as a function of its energy and temperature we obtain a formula of partial charges.