• 대한방사선치료학회지
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• 제2권1호
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• pp.31-40
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• 1987

In the case of designing a high dose rate remote controlled afterloading treatment room with existing hospital facilities. We must construct the effective protective barriers so as to reduce the primary and scattered radiation up to the maximum permissible dose level. It is difficult to reinforce the barrier thickness of the shielding requirements because of the limited space and the problem of the existing building structure at the surrounding area. Therefore we can reduce the intensity of primary radiation to the required degree at the location of interest with installing the appropriate I shaped Pb barriers between the radiation source and the shielding wall of the concrete. As a result, it was possible to reduce the intensity of the primary radiation below the M.P.D level by using additional Pb barriers instead of increasing thickness of concrete wall.

• Communications for Statistical Applications and Methods
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• 제24권1호
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• pp.43-65
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• 2017

We propose a flexible cure rate survival model by assuming that the number of competing causes of the event of interest has the Poisson distribution and the time for the event follows the gamma-G family of distributions. The extended family of gamma-G failure-time models with long-term survivors is flexible enough to include many commonly used failure-time distributions as special cases. We consider a frequentist analysis for parameter estimation and derive appropriate matrices to assess local influence on the parameters. Further, various simulations are performed for different parameter settings, sample sizes and censoring percentages. We illustrate the performance of the proposed regression model by means of a data set from the medical area (gastric cancer).

• Journal of Yeungnam Medical Science
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• 제37권3호
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• pp.159-168
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• 2020

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infants or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

• Journal of Yeungnam Medical Science
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• 제35권1호
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• pp.27-35
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• 2018

Diabetes and depression are serious chronic conditions. As a result of their increasing prevalence, diabetes and depression, together with population growth and aging, are public health issues. The rate of depression in adults with either type 1 diabetes or type 2 diabetes is high relative to the general population. The coexistence of diabetes and depression has attracted much interest. Although it is unclear whether diabetes and depression are causally linked, most studies have shown that the association between diabetes and depression might be bidirectional. Currently, emotional well-being is becoming an increasingly important aspect of diabetes care and self-management. Psychiatric disorders and diabetic distress among people with diabetes may increase the risk of diabetes complication and mortality. Thus, assessment and appropriate management of depression in people with diabetes should be considered to achieve psychological well-being and optimize medical outcomes.

• 플랜트 저널
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• 제11권1호
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• pp.30-38
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• 2015

본 연구는 최근 도입된 단기사채를 통해 한국수출입은행의 대외채무보증과 연계하여 자산유동화 구조에 접목한 자산담보부 단기사채의 금리를 추정하고 해외 투자개발형 민자발전사업의 수주 확대를 위한 프로젝트파이낸스의 한 방안으로 이용할 수 있는지에 대한 것이다. 회사채 신용등급 AA-부터 BBB+까지 건설사 자산담보부 단기사채와 비교한 결과, 자산 유동화 구조와 접목한 한국수출입은행의 대외채무보증부 자산담보부 단기사채는 금리 경쟁력이 있고, 프로젝트의 자기자본수익률이 개선됨을 확인할 수 있었다. 특히, 본 금융구조는 회사채 등급이 낮은 시공사에 적용할수록 더 높은 자기자본수익률 확보가 가능함을 알 수 있었다. 이를 통해, 경쟁력 있는 자산담보부 단기사채 금융조건은 수요 창출 및 수익성 확보는 물론 우리기업의 해외 투자개발형 민자발전사업 수주확대에 기여할 것으로 기대된다.

• KDI Journal of Economic Policy
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• 제12권3호
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• pp.125-151
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• 1990

본고(本稿)는 경제자유화(經濟自由化)의 대표적 사례(事例)로 일컬어지는 남미(南美) 자유화과정(自由化過程)을 살펴보고 몇가지 교훈(敎訓)을 도출해 보고자 함에 목적이 있다. 칠레, 아르헨티나, 우르과이의 남미(南美) 3국(國)은 각기 서로 다른 과정(過程)을 밟아 경제자유화(經濟自由化)를 이룩하려고 하였는데 실제로 무역(貿易) 및 자본시장(資本市場)의 개방(開放)을 추진하여 자원배분(資源配分)의 실효성(實效性)을 높이려면 국내거시경제상황의 안정(安定)이 필수적임을 각국(各國)의 경험(經驗)이 보여주고 있다. 우선 재정(財政) 통화정책(通貨政策)의 안정(安定) 없이는 무역(貿易) 자본시장(資本市場)의 개방(開放)이 오히려 국내경제(國內經濟)를 불안하게 한다. 재정적자(財政赤字)는 실질이자율(實質利子率)을 올리거나 실질평가절상(實質平價切上)을 유발하여 이 경우 자본시장(資本市場)이 개방되면 오히려 국내경제불안이 가중된다. 둘째, 구매력평가설(購買力評價設)과 이자율평가설(利子率平價設)에 기초한 통화론적(通貨論的) 안정화정책(安定化政策)은 각국(各國)에 내재한 여러가지 구조적(構造的) 요인(要因)으로 이론에 걸맞는 성과(成果)를 거두기 어려우며 오히려 자유화과정(自由化過程)에서 실질환율(實質換率)과 실질이자율(實質利子率)의 불안정(不安定)을 초래한다. 마지막으로 경제자유화(經濟自由化)의 순서(順序)와 속도(速度)는 정치(政治) 경제적(經濟的) 상황(狀況)에 따라 달라지며 이론적(理論的) 실증적(實證的)으로 최적(最適)의 자유화계획(自由化計劃)을 결정할 수 없다. 그러나 무역자유화(貿易自由化) 및 자본자유화(資本自由化)를 순차적으로 추진하면서 실질환율(實質換率)과 실질이자율(實質利子率)의 안정(安定)에 유의하는 것이 바람직하다.

• 대한핵의학회지
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• 제36권1호
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• pp.8-18
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• 2002

Early and accurate diagnosis of tumors using positron omission tomography (PET) has been the focus of considerable interest due to its high metastasis and mortality rates at late detection. PET radiopharmaceuticals-which exhibit a high tumor-to-background uptake ratio, and appropriate metabolic characteristics, and pharmacokinetics-are attractive tools for tumor imaging. Tumor imaging by these radiopharmaceuticals are based on metabolic and receptor imaging. The former is based on accelerated metabolism in tumor tissue compared to normal tissue and the rate roughly corresponding to the rate of growth of tumors. Radiopharmaceuticals for this purpose include radiolabeled sugars, amino acids, and nucleosides which detect increased glucose utilization, protein synthesis, and DNA synthesis, respectively. Tumor receptor imaging is based on the proliferation of tumor cells regulated by many hormones and growth factors, which bind to the corresponding receptors and exhibit the biological responses Radiopharmaceuticals used to image the tumor receptor systems may be ligands for the specific receptors and antibodies for the growth factor receptors. Some antitumor agents have been labeled with radionuclides and used to study in vivo biodistribution and pharmacokinetics in humans. This overview describes typical PET radiopharmaceuticals used for tumor imaging based on their uptake mechanisms.

• 설비공학논문집
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• 제16권11호
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• pp.1060-1067
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• 2004

To apply an analysis method of life cycle cost when assessing economics of equipment system, we should basically set up preconditions such as useful life, price escalation rate, interest rate, etc. as well as consider a calculation algorism of source energy and heat source system, which is a complex process for life cycle costing. For this reason, equipment designers tend to plan heat source systems, without a thorough investigation on economics of alternative systems at the pre-design phase. In this process, architectural designers should adopt a proper heat source system, which is one of the most important factors for planning an appropriate architectural design, through a discussion with equipment designers in a short time. In order to offer an evaluation method for equipment designers to analyze economics of an alternative heat source system easily at the pre-design phase, this research would define the simplified economics, evaluation method through analysis of existing papers for economics evaluation, and examine validity through comparison of simplified method values ($LCC_{EC}$) and life cycle costing values ($LCC_{15}$) for six alternative heat source systems.

• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.103-111
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• 2021

A series of experiments have been carried out by using National Geographic Information Institute(NGII)'s Continuously Operating Reference Station (CORS) data with various strategies to analyze the impact of multi-GNSS measurements on baseline processing. The results of baseline processing were compared in terms of ambiguity fixing rate, precision, and hypothesis tests were conducted to confirm the statistical difference. The combination of multi-GNSS measurements has helped to improve ambiguity fixing rate, especially under harsh positioning environments. Combination of GPS, Galileo, BeiDou could get better precision than that of GPS, GLONASS, Galileo, and adding QZSS made the baseline solution's vertical component more precisely. The hypothesis tests have statistically confirmed that the inclusion of the multi-GNSS in the baseline processing enables not only to reduce field observation time length but also to enhance the solution's precision. However, it is of interest to notice that results of the baseline solution are dependent upon the software used. Hence, comprehensive studies should be performed shortly to derive the best practice to select the appropriate software.

• Asian Pacific Journal of Cancer Prevention
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• 제15권12호
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• pp.4839-4842
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• 2014

Background: Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). Materials and Methods: This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. Results: The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. Conclusions: This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.