• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.339-342
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• 2006

The power outputs of renewable energy such as wind turbines and solar energy powers depend on natural sources. Accordingly, the power outputs of renewable energy is different from capacity rate at the time of peak load. Because of this gap, long term electricity power plan can have over-estimated reserve margin. So, this paper suggests the chronological approach to calculate the reliability assessment of renewable energy.

• Radiation Oncology Journal
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• 제32권1호
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• pp.1-6
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• 2014

Purpose: To evaluate the outcome of ductal carcinoma in situ (DCIS) patients who underwent surgery followed by radiation therapy (RT). Materials and Methods: We retrospectively reviewed 106 DCIS patients who underwent surgery followed by postoperative RT between 1994 and 2006. Ninety-four patients underwent breast-conserving surgery, and mastectomy was performed in 12 patients due to extensive DCIS. Postoperative RT was delivered to whole breast with 50.4 Gy/28 fx. Tumor bed boost was offered to 7 patients (6.6%). Patients with hormonal receptor-positive tumors were treated with hormonal therapy. Results: The median follow-up duration was 83.4 months (range, 33.4 to 191.5 months) and the median age was 47.8 years. Ten patients (9.4%) had resection margin <1 mm and high-grade and estrogen receptor-negative tumors were observed in 39 (36.8%) and 20 (18.9%) patients, respectively. The 7-year ipsilateral breast tumor recurrence (IBTR)-free survival rate was 95.3%. Resection margin (<1 or ${\geq}1$ mm) was the significant prognostic factor for IBTR in univariate and multivariate analyses (p < 0.001 and p = 0.016, respectively). Conclusion: Postoperative RT for DCIS can achieve favorable treatment outcome. Resection margin was the important prognostic factor for IBTR in the DCIS patients who underwent postoperative RT.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.99-108
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• 2021

As expansion of interest income business faces several limitations, non-interest revenue can play a vital role in increasing the net profit margin and the productivity of the assets to sustain the growth rate. This study aims to analyze the Effect level (partial or total) of a bank's size on the relationship between non-interest revenue and the sustainable growth rate of Jordanian commercial banks. Baron and Kenny's methodology (1986) was adopted to test and analyze the effect of non-interest revenue: including the bank's size, on the sustainable growth rate during the period from 2008-2019. Data collection was done for thirteen commercial banks which constituted 100% of the study population. Testing four hypotheses by using Amos program and a regression model to diagnose the partial and total effect of size. Findings indicate that there is a nonlinear relationship between Non-IR and SGR due to the total effect of bank size on the sustainable growth rate. The results of this study is expected to enable the banks to diversify their revenue to support financial performance towards healthy growth without facing additional financial problems. This study adopted a different methodology from the prior efforts, by using the mediation effect role to verify the effect of non-interest revenue.

• 치과방사선
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• 제22권2호
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• pp.339-348
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• 1992

The purpose of this study was to evaluate the correlationship between histopathologic types of ameloblastoma and their radiographic appearances. The materials for this study consisted of 106 patients diagnosed as ameloblastoma both radiographically and histologically. The obtained results were as follows: 1. The incidence of ameloblastoma in male(60cases, 56.6%) was slightly higher than that in female (46 cases, 43.4%). The average age was estimated as 30.7 years with a range from 6 to 76 years. The second decade revealed the highest rate. 2. 106 ameloblstomas were histopathologically classified as 36 unicystic, 28 plexiform, 20 follicular, 14 acanthomatous, 7 granular cell, and 1 basal cell ameloblastoma. 3. Unilocular, soap-bubble appearance and scalloped margin were the radiographic appearances frequently seen in unicystic ameloblastoma. The predominant radiographic appearance of plexiform ameloblastoma showed unilocular radiolucency with scalloped margin. 4. 19.8%, 21 cases of ameloblastoma in this study showed containing tooth in their tumor mass by radiography. 5. Root resorption occured in 37 cases(34.9%) and tooth displacement in 7 cases(6.6%). Root resorption and tooth displacement occured in same patient were 24 cases(22.6%). 6. Recurrence occured in 21.7% and average year between initial treatment and recurrence were 2 years.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1527-1534
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• 2016

Online voltage stability monitoring using real-time measurements is one of the most important tasks in a smart grid system to maintain the grid stability. Loading margin is a good indicator for assessing the voltage stability level. This paper presents an Extreme Learning Machine (ELM) approach for estimation of voltage stability level under credible contingencies using real-time measurements from Phasor Measurement Units (PMUs). PMUs enable a much higher data sampling rate and provide synchronized measurements of real-time phasors of voltages and currents. Depth First (DF) algorithm is used for optimally placing the PMUs. To make the ELM approach applicable for a large scale power system problem, Mutual information (MI)-based feature selection is proposed to achieve the dimensionality reduction. MI-based feature selection reduces the number of network input features which reduces the network training time and improves the generalization capability. Voltage magnitudes and phase angles received from PMUs are fed as inputs to the ELM model. IEEE 30-bus test system is considered for demonstrating the effectiveness of the proposed methodology for estimating the voltage stability level under various loading conditions considering single line contingencies. Simulation results validate the suitability of the technique for fast and accurate online voltage stability assessment using PMU data.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.91-98
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• 2017

Performance of a low speed axial compressor is enhanced through a proper configuration of blade row tip injection and casing treatment of groove type. Air injectors were mounted evenly spaced upstream of the blade row within the casing groove and were all aligned parallel to the compressor axis. The groove, which covers all the blade tip chord length, extends all-round the casing circumference. Method of investigation is based on solution of the unsteady form of the Navier-Stokes equations utilizing $k-{\omega}$ SST turbulence model. Extensive parametric studies have been carried out to explore effects of injectors' flow momentums and yaw angles on compressor performance, while being run at different throttle valve setting. Emphasis has been focused on situations near to stall condition. Unsteady numerical analyses for untreated casing and no-injection case for near stall condition provided to discover two well-known criteria for spike stall inception, i.e., blade leading edge spillage and trailing edge back-flow. Final results showed that with only 6 injectors mounted axially in the casing groove and at yaw angle of 15 degrees opposite the direction of the blade row rotation, with a total mass flow rate of only 0.5% of the compressor main flow, surprisingly, the stall margin improves by 15.5%.

• 한국통신학회논문지
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• 제35권8A호
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• pp.743-751
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• 2010

OFDMA 초소형 기지국은 기존의 대형 기지국을 대신하여 실내에서의 고속 데이터 통신을 지원하기 위해 개발된 기술이지만 아직 실용화를 위해 해결해야할 여러 문제를 가지고 있다. 특히 초소형 기지국이 대형 기지국과 같은 주파수 대역을 사용할 경우 발생하는 셀간 간섭 문제는 시스템의 성능을 저하시키는 주요 원인이 된다. 초소형 기지국에 대한 사용 권한이 없는 사용자는 초소형 기지국의 서비스 영역 내에서도 대형 기지국과 통신을 수행하여야 하며 이때 하향링크에서 초소형 기지국의 전송 신호는 대형 기지국 사용자에게 간섭으로 작용하게 된다. 따라서 초소형 기지국의 전송 전력을 최소화하여 대형 기지국 사용자에게 미치는 간섭을 제어할 필요가 있다. 본 논문에서는 초소형 기지국의 전력 할당을 위한 margin adaptive 문제를 정의하고 이를 해결하기 위한 휴리스틱기법을 제안한다. 또한 모의실험을 통해 제안한 기법의 성능을 검증한다.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.807-813
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• 2011

High precision of planning in the preoperative phase can contribute to increase operational safety during computer-aided spinal fusion surgery, which requires extreme caution on the part of the surgeon, due to the complexity and delicacy of the procedure. In this paper, an advanced preoperative planning framework for spinal fusion is presented. The framework is based on spinal pedicle data obtained from CT (Computed Tomography) images, and provides optimal insertion trajectories and pedicle screw sizes. The proposed approach begins with safety margin estimation for each potential insertion trajectory that passes through the pedicle volume, followed by procedures to collect a set of insertion trajectories that satisfy operation safety objectives. The radius of a pedicle screw was chosen as 70% of the pedicle radius. This framework has been tested on 68 spinal pedicles of 8 patients requiring spinal fusion. It was successfully applied, resulting in an average success rate of 100% and a final safety margin of $2.44{\pm}0.51mm$.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.442-456
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• 1993

Financial stability is the foremost prerequisite for the continuous growth and development of hospitals. The present study aimed at developing a deterministic model using the factors which affect the hospitals profitability and at discovering which factor affected the hospital profitability. The study conducted questionnaire surveys on all general hospitals, with the exception of special hospitals, with over eighty hospital beds. Of the 274 subject hospitals, 136 of them, consituting 49.6% of the whole, were used in the study. The results are as follows. 1. In the deterministic model, outpatient revenue was affected more by the number of physician visits than by outpatient service intensity. Inpatient revenue was found to be affected more by the number of discharged patients than by inpatient service intensity. However, the increase rate of the service intensity not only contributed in stepping up the operating margin by $4{\sim}8%$ in outpatient and $3{\sim}6%$ in inpatient, but it was statistically significant. 2. Among the factors which determined the operating cost within the deterministic model, the number of patients had a greater impact on the operating cost than the resource consumption per patient. 3. The resource consumption per patient were proved to have the greatest effect on the profitability within the probabilistic model. The management cost per adjusted patient, in particular, was proven to have a statistically significant effect on the profitability in all hospitals.

• 한국환경복원기술학회지
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• 제16권5호
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• pp.39-47
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• 2013

The agricultural area is a priority to develop than the natural area for land developments. However, the importance of agricultural biodiversity is emphasized recently. The agricultural area does not only provide food for human and habitat for wild life but also contribute to improve biodiversity. It is necessary to preserve the agricultural area with rich biodiversity. The study was conducted to analyze biodiversity of insects for conservation value assessment of agricultural areas. According to the results of field survey, there is higher biodiversity index in agricultural areas surrounding the forest or small size agricultural areas. By contrast, the index is lower in agricultural areas near roads or in the intensive agricultural area. The results show that there is high biodiversity in agricultural areas, especially margin agricultural area such as below 2ha and over slop rate of 15%. Therefore, further studies should be conducted field survey more to generalize for biodiversity in agricultural area, and establish the criteria to protect agricultural area from land developments.