• 대한골관절종양학회지
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• 제9권2호
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• pp.131-138
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• 2003

서론: 악성 말초 신경막 종양(Malignant peripheral nerve sheath tumor, MPNST)에 대하여 수술, 항암제 투여, 방사선 치료 등을 시행하고 이에 따른 종양학적 결과를 분석하여 보다 합리적인 치료 방법을 알아보고자 하였다. 재료 및 방법: 1986년 2월부터 1996년 11월까지 본원에 등록된 MPNST 환자 34례를 대상으로 하였다. 남자가 17례, 여자가 17례였고 평균연령은 41세(18세~74세)였다. 종양의 위치는 하지가 17례, 상지 11례, 체간부 4례, 후복막 2례였다. AJC(American Joint Committee on Cancer) 분류에 의한 종양의 병기는 stage IA가 2례, stage IIA 2례, stage IIB 6례, stage III 16례, 그리고 stage IV가 8례였다. 치료 방법으로는 26례에서 수술과 항암제 투여 그리고 때에 따라서 방사선치료를 시행하였고 3례에서는 수술만, 3례에서는 항암제 투여나 방사선 치료만 시행하였다. 평균 추시 기간은 33.5개월(5.6개월~141.1개월)이었다. Kaplan-Meiyer 법으로 생존율을 구하였고, log rank test로 비교 분석 하였다. 결과: 최종 추시상 질병 상태는 14례에서 CDF(continuous disease free)였고, 2례가 NED(no evidence of disease), 2례 AWD(alive with disease), 그리고 14례가 DOD(died of disease)였다. 실제(actuarial) 5년 생존율과 10년 생존율 은 53.5 %와, 35.7%였다. 수술 후의 국소 재발율은 24.1%였다. 병기별 5년 실질 생존율은 stage I이 100%, stage II 85.7%, stage III 55.9%였고 stage IV의 경우 2년 실질 생존율이 14.3%였다(p=0.04). Stage II, III에서 수술한 경우 21례에서, 광범위 이상의 절제연을 얻었던 경우가 15례로 5년 실질생존율이 76.0%였고 병소내이거나 변연부 절제연의 경우는 6례로 40.0%였다(p=0.26). 4회차 이상의 항암화학요법제를 투여한 군(8례)의 5년 실질생존율은 71.4%였고 3회차 이하의 불충분한 항암제투여를 시행한 군(6례)의 3년 실질생존율은 83.3%였다(p=0.96). Stage II, III 중 방사선 치료 없이 수술 받은 19례에서 병소내 절제나 변연부 절제를 시행했던 5례는 3례가 국소 재발하였고(60.0%) 광범위 절제를 시행한 14례는 4례가 국소 재발하였다(28.6%). 수술 전 또는 후에 방사선치료를 시행하였던 8례에서는 국소재발이한 예도 없었다. 결론: 외과적 절제연(surgical margin)이 국소 재발에는 중요한 요인이었고, 통계적으로 의미있는 수치는 아니었지만 생존율에도 영향을 주는 경향이 있는 것으로 생각된다. 기존의 항암제 투여는 국소 재발이나 생존율상에 통계적으로 의미있는 차이를 보이지 못하였다. 수술전과 수술후 시행하였던 방사선치료는 국소 재발을 줄이는데 어느 정도의 효과를 보였다.

• 한국정밀공학회지
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• 제2권3호
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• pp.28-40
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• 1985

In this study, to check up on the effect of the components of cutting resistance upon friction between drill and inside wall of hole in drilling, the experiment was performed with individual specimen of carbon steel, cast iron, aluminium alloy under various cutting conditions: depth of hole, cutting speed, feed rate, shape and material of specimen. On the basis of the experimental results, the following conclusions are drawn; 1. The components of cutting resis- tance were increased in proportion to the increase of depth of hole owing to frictional resistance of drill margin and chip-jamming. 2. As feed rates increase, torque and thrust were increased. When comparing to the increasing rate for these components respecitively, thrust is higher tendency than torque. 3. As drill diameter increase, torque and thrust were increased. When comparing to the increasing rate for these components respectively, torque is higher tendency than thrust. 4. In the case of torque, the frictional resistance between drill margin and inside wall of drilled hole accounts for about 20 percent of carbon steel, 14 of cast iron, 10 aluminium alloy in drilling. But the effect of thrust force could be negligible. 5. Comparison between the theoretical and experimental results showed a close agreement so far as depth of hole is about three times of drill diameter. But there was a wide difference between them beyond the rane of three times, because of characteristics of the drilling process.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.394-413
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• 2010

The object of this paper is to identify the key elements that impact a radiation dose at EAB (Exclusion Area Boundary). This study is based on the AST (Alternative Source Terms) as defined in Regulatory Guide 1.183. The LOCA (Loss of Coolant Accident) and the LRA (Locked Rotor Accident) are selected as limiting cases. A sensitivity analysis of accidental behavior with respect to various parameters during LOCA and LRA at Kori Unit 1 is also undertaken for the following objectives: to determine the limiting parameters, to find the impact trend of the radiation dose, and to find the safety margin between AST and TID (Technical Information Document) methodologies. This work confirms that key parameters are particulate removal rate, decontamination factor, iodine chemical form, gap fraction, partitioning factor, and the impact of isotopes group. Comparing TID with AST, the radiation dose of TID is about 80% greater than that of AST under a LOCA, and about 60% greater than that of AST for the case of a LRA; thus the safety margin is remarkably increased when the AST is used. In this work, the sensitivity analysis results are presented in terms of a sensitivity index called the "NDD (Normalized Dose Difference)", which compares the impact of parameters with that of a reference case. These values are derived by using a combination of the leak rate (primary to secondary), iodine chemical form, gap fraction, partitioning factor, spray removal rate, source term, and other variables.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.1063-1070
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• 2017

This paper presents a method for forecasting future uranium prices that is used as input data to calculate the uranium cost, which is a rational key cost driver of the nuclear fuel cycle cost. In other words, the statistical autoregressive integrated moving average (ARIMA) model and existing engineering cost estimation method, the so-called escalation rate model, were subjected to a comparative analysis. When the uranium price was forecasted in 2015, the margin of error of the ARIMA model forecasting was calculated and found to be 5.4%, whereas the escalation rate model was found to have a margin of error of 7.32%. Thus, it was verified that the ARIMA model is more suitable than the escalation rate model at decreasing uncertainty in nuclear fuel cycle cost calculation.

• 무역상무연구
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• 제38권
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• pp.265-302
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• 2008

This paper intends to analyse some legal issues on "Zeroing" which is based on the article 2.4.2 under the WTO Anti-dumping Agreement. "Zeroing" stands for a specific methodology in calculating a general dumping margin for a product in question under which negative individual dumping margins are treated as zero (thus "zeroed") before aggregating all individual dumping margins. The article 2.4.2 of the Anti-dumping Agreement regulates three types of calculating methodology on dumping margin as first symmetrical method(average-to-average: A-A), second symmetrical method(individual-to-individual: I-I) and asymmetrical method(average-to-individual: A-I). However, this article does not have any provisions about the "Zeroing" practice. In their anti-dumping practices, the EC and the United-States calculated dumping margin based on the "Zeroing", but this methodology has been disputed in the Dispute Settlement Body(DSB) of the WTO. This paper analysed their legal problems with some WTO cases in particular concerning EC-Bed Linen, U.S.-Softwood Lumber Zeroing, U.S.-Zeroing(EC) and U.S.-Sunset Review(Japan) cases. On the basis of theses analysis, we can therefore ask some questions as follows; To begin with, although the article 2.4.2 of the WTO Anti-dumping Agreement does not clearly refer to the "Zeroing", how do some developing countries, as the U.S.A and the E.U. calculate dumping margin as the "Zeroing"? Secondly, what is the relationship between the symmetrical method and asymmetrical method to the dumping margin? And if we adopt the zeroing method, what is the different rate to anti-dumping margin? Thirdly, although the Panel decided that the zeroing methodology of dumping margin used by th U.S.A in administrative review between the U.S.A and the E.U, why does the Appellate Body made the decision that the american methodology is incompatible with the WTO Anti-dumping Agreement? Lastly, what will be affected the upper decision taken by the Appellate Body to the DDA negotiation of anti-dumping matters? Even though the WTO Appellate made a decision that the zeroing method is incompatible with the principles of the WTO law, this methodology contains a lot of problems. Some members of the WTO as the U.S.A and the E.U did not officially declare this methodology to abandon, and the debate concerned is arguing. Therefore this paper tried to present the adequate solution in order to promote the zeroing methodology in the international anti-dumping system and practices.

• 대한골관절종양학회지
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• 제3권2호
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• pp.89-97
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• 1997

Twenty hundred and five out of 266 patients who were registered in Korea Cancer Center Hospital from Mar. 1985 to Jan. 1994, were analyzed in the aspect of survival and local recurrence. Fifty one patients were excluded due to inadequate data and follow up. Prognostic factors for survival were evaluated statistically. One hundred and four cases were male, 101 female. Average age was 39.7(range 1 to 77) year with a peak incidence around 4th decade. The most frequent diagnosis was malignant fibrous histiocytoma(MFH)(24.1%). Liposarcoma, synovial sarcoma, rhabdomyosarcoma, malignant peripheral nerve sheath tumor and fibrosarcoma were relatively common diagnostic entities, in decreasing order. In location, extremity was 179(87.3%) and trunk 26(12.7%). Average follow up period was 7.5 years(6 months to 10 years). Actuarial 5 years and 10 years survival rate were 64.0% and 40.8% respectively. In univariate analysis with log-lank test, significant differences in survival rate were noted in histopathological diagnosis, size(10 cm), stage and metastasis. Age, sex, tumor location, tumor depth and local recurrence didn't affect the survival rate. Adjuvant chemotherapy and/or radiotherapy did not affect overall survival rate, but lowered the local recurrence rate when compared with surgery only. Surgical margin did not affect the survival rate, but local recurrence rate was different according to each margin; 5.7% in more than wide; 39.5% in marginal; and 60.0% in intralesional excision. In multivariate analysis for results of univariate analysis with Cox's propotional model, metastasis was a meaningful factor for survival of soft tissue sarcoma.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6935-6940
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• 2013

Background: This study aimed to develop a prognostic model in patients with early-stage cervical squamous cell carcinoma based on clinicopathological features, including invasive margin characteristics. Materials and Methods: Clinicopathological features and outcomes of 190 patients with FIGO stage IB-IIA cervical squamous cell carcinoma treated by surgery were collected and analyzed for factors associated with tumor recurrence. In addition to well-recognized pathological risk factors, the pathological characteristics of invasive margin (type of invasive pattern and degree of stromal desmoplasia and peritumoral inflammatory reaction) were also included in the analysis. Multiple scoring models were made by matching different clinicopathological variables and/or different weighting of the score for each variable. The model with the best performance in the prediction of recurrence and decreased survival was selected. Results: The model with the best performance was composed of a combined score of invasive pattern, lymphovascular space invasion (LVSI), and degree of inflammatory reaction and stromal desmoplasia (total score =10). Compared to those with score ${\leq}8$, the patients with score 9-10 had a significantly higher recurrence rate in the overall group (p<0.001) and the subgroup without adjuvant therapy (p<0.001), while the significance was marginal in the subgroup with adjuvant therapy (p=0.069). In addition, the patients with score 9-10 had a higher rate of tumor recurrence at distant sites (p=0.007). The disease-free survival was significantly lower in the patients with score 9-10 than those with score ${\leq}8$ among the overall patients (p<0.001), in the subgroup without adjuvant therapy (p<0.001), and the subgroup with adjuvant therapy (p=0.047). Conclusions: In this study, a prognostic model based on a combination of pathological characteristics of invasive margin and LVSI proved to be predictive of tumor recurrence and decreased disease-free survival in patients with early-stage cervical squamous cell carcinoma.

• 대한전자공학회논문지TC
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• 제46권8호
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• pp.1-9
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• 2009

본 논문은 무인기용 대전자전 송수신 장치 개발에 대한 연구로 재밍(jamming) 환경에 강건한 대역확산(DSSS) 송수신기 개발에 대해 기술한다. 대역확산 방식은 데이터의 전송률 보다는 재밍마진이 중요하기 때문에 송수신 장치의 개발 목표로 재밍마진이 15dB 이상이고, 확산코드를 변경 가능한 송수신기를 제작하는 것이다. 멀티패스 성분을 이용하기 위한 레이크 수신기와, FEC로 부호이득이 7.2dB인 터보 코드를 적용하였다. 본 논문에서는 대역확산 송수신 장치의 전체적인 구조와 설계방법, 기능시험 결과를 기술하고 결론을 맺는다.

• International Journal of Contents
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• 제2권2호
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• pp.10-16
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• 2006

In this paper, we propose a predictive resource metric region (RMR) based radio resource metric estimation (RRME) mechanism, which utilizes a resource metric mapping function (RMMF), both of which permit efficient inter-working between the physical layer and higher layers for envisaging multimedia service applications over a CDMA communication system platform. The RMR can provide the acceptable resource region where QoS and acceptable link quality can be guaranteed with an achievable resource margin to be utilized in terms of capacity margin, the degree of confidence (DCL) of user, second-order statistics of Eb/Io. With predicted capacity margin and variance, DCL can deliver decision parameters with which an adaptive QoS based admission control can perform well taking capacity and resource availability into account in a dynamic and predictive manner. Combined with advanced techniques such as adaptive modulation or rate control and power control, the proposed mechanism can adjust the conventional stringent link quality information efficiently, and deliver accurate information of the resource availability. Thus, these can guarantee the maximization of resource utilization of multimedia service applications.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.684-701
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• 2016

The Gaussian process model (GPM) is a flexible surrogate model that can be used for nonparametric regression for multivariate problems. A unique feature of the GPM is that a prediction variance is automatically provided with the regression function. In this paper, we estimate the safety margin of a nuclear power plant by performing regression on the output of best-estimate simulations of a large-break loss-of-coolant accident with sampling of safety system configuration, sequence timing, technical specifications, and thermal hydraulic parameter uncertainties. The key aspect of our approach is that the GPM regression is only performed on the dominant input variables, the safety injection flow rate and the delay time for AC powered pumps to start representing sequence timing uncertainty, providing a predictive model for the peak clad temperature during a reflood phase. Other uncertainties are interpreted as contributors to the measurement noise of the code output and are implicitly treated in the GPM in the noise variance term, providing local uncertainty bounds for the peak clad temperature. We discuss the applicability of the foregoing method to reduce the use of conservative assumptions in best estimate plus uncertainty (BEPU) and Level 1 probabilistic safety assessment (PSA) success criteria definitions while dealing with a large number of uncertainties.