• Title/Summary/Keyword: Evaluation of Value at Risk

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Guideliness of the Parameters Using Integrated Test in Down Syndrome Risk Prediction (다운증후군위험도 예측에서 통합선별검사를 이용한 파라미터의 유의성)

  • Lee, Jin-Won;Go, Sung-Jin;Kang, Se-Sik;Kim, Chang-Soo
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.549-555
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    • 2016
  • This study was an evaluation of the significance of each parameter through aimed at pregnant women subjected to screening test(integrated test) in predicting risk of Down syndrome. We retrospectively analysed the correlation of risk of Down's syndrome with Nuchal Translucency(NT) images measured by ultrasound, Pregnancy Associated Plasma Protein A(PAPP-A), alpha-fetoprotein(AFP), unconjugated estriol(uE3), human chorionic gonadotrophin(hCG) and Inhibin A by maternal serum. As a result, a significant correlation with NT, uE3, hCG, Inhibin A is revealed with Down's syndrome risk(P<.001). In ROC analysis, AUC of Inhibin A is analysed as the biggest predictor of Down's syndrome(0.859). And the criterion for cut-off was inhibin A 1.4 MoM(sensitivity 81.8%, specificity 75.9%). In conclusion, Inhibin A was the most useful in parameters to predict Down's syndrome in the integrated test. If we make up for the weakness based on the cut-off value of parameters they will be able to be used as an independent indicator in the risk of Down's syndrome screening.

Comparison of the Frequency of Unsafe Ship-Handling Situations and the Frequency of Marine Accidents at the Kurushima Strait

  • Yasuda, Masaru;Inoue, Kinzo;Usui, Hideo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.10a
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    • pp.184-190
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    • 2006
  • It is requested to be evaluated whether environmental change in marine traffic passage by maintenance work affect ship handling, safety, when re-design of traffic passage is planned. In the maintenance work, it is also important to evaluate the change of risk and also benefits. However, in a current evaluation index, it is difficult to evaluate the benefit. The recently developed safety index that is led by employing the Unsafe Ship-handling situations model (US-model) is able to estimate risk level of marine accident in a process of a ship handling. We have already reported the relation of the ratio of 10-3 in harbors (Yokohama, Kobe, and Osaka in Japan) [1]. In this study, we acquired the relation of the ratio between the US value and the marine accident at a narrow waterway; Kurushima Strait in Japan, using a ship handling simulator. And we experimented to estimate a marine accident reduction achieved by the maintenance work of the altered shape of passage.

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Evaluation of Risk Factors for Uterine Myoma Diagnosed by Ultrasonography (초음파로 진단된 자궁근종의 위험인자 평가)

  • Yang, Sung-Hee
    • Journal of radiological science and technology
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    • v.44 no.4
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    • pp.307-313
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    • 2021
  • The purpose of this study was to analyze the risk factors for uterine myoma diagnosed by ultrasonography in Korea women and to evaluate the risk. Among the patients who visited the outpatient department of obstetrics and gynecology at I hospital in Busin between January 2019 and March 2021 for the purpose of examination, 98 patients in the experimental group diagnosed with uterine myoma and 163 patients in the normal control group without other diseases were retrospectively conducted. Among the general characteristics of the subjects, age, body mass index, parity, and menopause showed significant differences between the myoma group and the normal control group. ROC(receiver operating characteristic) curve analysis and logistic regression analysis were performed to obtain the cut off value and odds ratio that can predict the occurrence of uterine myoma. The cut off value for the prediction of uterine myoma was determined to be 30 years old and a body mass index of 23 kg/m2. After that adjusting for menopause, non menopausal cases with a body mass index of 23 kg/m2 and over 39 years of age had the highest odds ratio of 6.04. Therefore, premenopausal women over 40 years of age require regular checkups and thorough weight management. This study was conducted with a small number of subjects. Therefore, there is a limit to generalizing to all Korean women. However, based on this study if a large scale prospective study considering various variables is made, it can play a role as a predictive marker in early detection of uterine myoma.

C7 Fracture as a Complication of C7 Dome-Like Laminectomy : Impact on Clinical and Radiological Outcomes and Evaluation of the Risk Factors

  • Yang, Seung Heon;Kim, Chi Heon;Lee, Chang Hyun;Ko, Young San;Won, Youngil;Chung, Chun Kee
    • Journal of Korean Neurosurgical Society
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    • v.64 no.4
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    • pp.575-584
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    • 2021
  • Objective : Cervical expansive laminoplasty is an effective surgical method to address multilevel cervical spinal stenosis. During surgery, the spinous processes of C2 and C7 are usually preserved to keep the insertion points of the cervical musculature and nuchal ligament intact. In this regard, dome-like laminectomy (undercutting of C7 lamina) instead of laminoplasty is performed on C7 in selected cases. However, resection of the lamina can weaken the C7 lamina, and stress fractures may occur, but this complication has not been characterized in the literature. The objective of the present study was to investigate the incidence and risk factors for C7 laminar fracture after C7 dome-like laminectomy and its impact on clinical and radiological outcomes. Methods : Patients who underwent cervical open-door laminoplasty combined with C7 dome-like laminectomy (n=123) were classified according to the presence of C7 laminar fracture. Clinical parameters (neck/arm pain score and neck disability index) and radiologic parameters (C2-7 angle, C2-7 sagittal vertical axis, and C7-T1 angle) were compared between the groups preoperatively and at postoperatively at 3, 6, 12, and 24 months. Risk factors for complications were evaluated, and a formula estimating C7 fracture risk was suggested. Results : C7 lamina fracture occurred in 32/123 (26%) patients and occurred at the bilateral isthmus in 29 patients and at the spinolaminar junction in three patients. All fractures appeared on X-ray within 3 months postoperatively, but patients did not present any neurological deterioration. The fracture spontaneously healed in 27/32 (84%) patients at 1 year and in 29/32 (91%) at 2 years. During follow-up, clinical outcomes were not significantly different between the groups. However, patients with C7 fractures showed a more lordotic C2-7 angle and kyphotic C7-T1 angle than patients without C7 fractures. C7 fracture was significantly associated with the extent of bone removal. By incorporating significant factors, the probability of C7 laminar fracture could be assessed with the formula 'Risk score = 1.08 × depth (%) + 1.03 × length (%, of the posterior height of C7 vertebral body)', and a cut-off value of 167.9% demonstrated a sensitivity of 90.3% and a specificity of 65.1% (area under the curve, 0.81). Conclusion : C7 laminar fracture can occur after C7 dome-like laminectomy when a substantial amount of lamina is resected. Although C7 fractures may not cause deleterious clinical outcomes, they can lead to an unharmonized cervical curvature. The chance of C7 fracture should be discussed in the shared decision-making process.

Evaluation of Treatment Plan Quality between Magnetic Resonance-Guided Radiotherapy and Volumetric Modulated Arc Therapy for Prostate Cancer

  • Chang Heon Choi;Jin Ho Kim;Jaeman Son;Jong Min Park;Jung-in Kim
    • Progress in Medical Physics
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    • v.33 no.4
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    • pp.121-128
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    • 2022
  • Purpose: This study evaluated the quality of plans based on magnetic resonance-guided radiotherapy (MRgRT) tri-Co-60, linac, and conventional linac-based volumetric modulated arc therapy (linac-VMAT) for prostate cancer. Methods: Twenty patients suffering from prostate cancer with intermediate risk who were treated by MAT were selected. Additional treatment plans (primary and boost plans) were generated based on MRgRT-tri-Co-60 and MRgRT-linac. The planning target volume (PTV) of MRgRT-based plans was created by adding a 3 mm margin from the clinical target volume (CTV) due to high soft-tissue contrast and real-time motion imaging. On the other hand, the PTV of conventional linac was generated based on a 1 cm margin from CTV. The targets of primary and boost plans were prostate plus seminal vesicle and prostate only, respectively. All plans were normalized to cover 95% of the target volume by 100% of the prescribed dose. Dosimetric characteristics were evaluated for each of the primary, boost, and sum plans. Results: For target coverage and conformity, the three plans showed similar results. In the sum plans, the average value of V65Gy of the rectum of MRgRT-linac (2.62%±2.21%) was smaller than those of MRgRT tri-Co-60 (9.04%±3.01%) and linac-VMAT (9.73%±7.14%) (P<0.001). In the case of bladder, the average value of V65Gy of MRgRT-linac was also smaller. Conclusions: In terms of organs at risk sparing, MRgRT-linac shows the best value while maintaining comparable target coverage among the three plans.

Evaluation of a Fall Risk Assessment Tool to Establish Continuous Quality Improvement Process for Inpatients' Falls (낙상예방 활동의 지속적 질 관리 프로세스 확립을 위한 위험 사정도구 평가)

  • Park, Ihn-Sook;Cho, In-Sook;Kim, Eun-Man;Kim, Min-Kyung
    • Journal of Korean Academy of Nursing Administration
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    • v.17 no.4
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    • pp.484-492
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    • 2011
  • Purpose: The aims of study were; (1) to evaluate the validity and sensitivity of a fall-risk assessment tool, and (2) to establish continuous quality improvement (CQI) methods to monitor the effective use of the risk assessment tool. Methods: A retrospective case-control cohort design was used. Analysis was conducted for 90 admissions as cases and 3,716 as controls during the 2006 and 2007 calendar years was conducted. Fallers were identified from the hospital’s Accident Reporting System, and non-fallers were selected by randomized selection. Accuracy estimates, sensitivity analysis and logistic regression were used. Results: At the lower cutoff score of one, sensitivity, specificity, and positive and negative predictive values were 82.2%, 19.3%, 0.03%, and 96.9%, respectively. The area under the ROC was 0.60 implying poor prediction. Logistic regression analysis showed that five out of nine constitutional items; age, history of falls, gait problems, and confusion were significantly associated with falls. Based on these results, we suggested a tailored falls CQI process with specific indexes. Conclusion: The fall-risk assessment tool was found to need considerable reviews for its validity and usage problems in practice. It is also necessary to develop protocols for use and identify strategies that reflect changes in patient conditions during hospital stay.

An Empirical Study on the Investment Evaluation of Korean Global Companies Using a Real Option Valuation Model (우리나라 글로벌 기업의 실물옵션을 이용한 투자안 평가 실증연구)

  • Jeong, Eui-Jong
    • Plant Journal
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    • v.8 no.3
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    • pp.42-48
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    • 2012
  • Under traditional analysis of the capital budgeting, NPV, it is assumed that management cannot react to deviation from the expected scenario of cash flow at the time of evaluation. In practice, however, it is less likely that the expected scenario will come true when new information arrives and uncertainty is resolved. Uncertainty and risk can be influenced through 'managerial flexibility', which becomes a central instrument for value creation. Real option framework including option to defer, option for staged investment, option to alter, option to abandon, option to switch, etc. takes this managerial flexibility into account. Therefore, it is more appropriate to use real option method to evaluate the project than the traditional DCF(discounted cash flow) tool if the firm has high volatility of the expected returns.

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The Effect of Online WOM of Menu Product Consumers on Product Perception Risk and WOM Effect

  • HEO, Yeong-Wook
    • Journal of Distribution Science
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    • v.18 no.3
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    • pp.77-85
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    • 2020
  • Purpose: This study examined marketing value as online word-of-mouth media in the foodservice industry, and it did research on online word-of-mouth (e-WOM) communication marketing schemes using mass communication in the industry. The study is also intended to investigate the impact of electronic word-of-mouth (e-WOM) information and communication on product awareness risks, benefits, and word-of-mouth (WOM) impacts on restaurant consumers. Research design, data, and methodology: The analysis was conducted on a valid questionnaire of 425 menu product consumers. The survey was conducted for two months in March 2019. The collected data was analyzed using SPSS and hierarchical regression analysis was applied. Results: It did empirical research on the reciprocal casual relations to online and the existing word-of-mouth communication that have to be preceded to understand characteristics of online word-of-mouth communication for the purpose of this study. The result is summarized as follows. First, the online word-of-mouth (e-WOM) effect on product recognition risk shows the statistically significant effect of information sender characteristics, information recipient characteristics, and online word-of-mouth (e-WOM) communication on product recognition risk. Second, the influence of online word-of-mouth (e-WOM) on product risk benefits shows that the information sender characteristics, the information receiver characteristics, and online communications have a statistically significant effect on product risk benefits. Third, online word of mouth risk recognition had a statistically significant effect on word of mouth acceptance. Fourth, online risk benefit had a statistically significant positive effect on word of mouth (WOM) effect. Conclusions: The communication between online word of mouth (e-WOM) sender and recipient had a positive influence on the product evaluation and attitude change in the foodservice industry, and the word-of-mouth (WOM) effect affected financial and non-financial performance. The results mentioned above indicated that the communication between the sender of the information and the receiver of the information had a positive effect on the product evaluation and attitude change of the menu consumer, and the word-of-mouth (WOM) result affected the financial. Therefore, the online word-of-mouth (e-WOM) effect has a positive effect on the word-of-mouth (WOM) effect of menu products when performed simultaneously and positively between the information sender and the information receiver.

Bond Ratings, Corporate Governance, and Cost of Debt: The Case of Korea

  • Han, Seung-Hun;Kang, Kichun;Shin, Yoon S.
    • The Journal of Asian Finance, Economics and Business
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    • v.3 no.3
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    • pp.5-15
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    • 2016
  • This study examines whether Korean rating agencies such as Korea Investors Service (KIS), National Information & Credit Evaluation (NICE), and Korea Ratings Corporation (KR), incorporate corporate governance into their corporate bond ratings in Korea. We find that the Korean rating agencies assign higher ratings to the bonds issued by Chaebol (Korean business group) affiliated firms. Our results also indicate that those rating agencies give higher ratings to the bonds with greater foreign investor share ownership. Moreover, if the rating agencies value corporate governance, higher rated firms should issue bonds at lower yield to maturity. We discover that Chaebol affiliation is counted favorably by the rating agencies. We find that investors are willing to pay lower risk premium for bonds with higher institutional ownership, but higher risk premium to bonds with greater equity ownership in the form of depository receipts. Therefore, even if the rating agencies and investors in Korea consider corporate governance (Chaebol affiliation and ownership structure) an important determinant in bond ratings and the yields to maturity, they have opposite views on institutional ownership and share ownership in the form of depository receipts.

Development of Non-Contact Penetration Measuring Device for Pile Driving Workers (항타 시공 작업자를 위한 비접촉식 관입량 측정기 개발)

  • Kim, J.K.;Kong, Y.K.;Choi, K.H.;Cho, M.U.;Kim, S.Y.;Kim, M.J.;Lee, J.H.;Park, Chae Won
    • Journal of the Korean Society of Safety
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    • v.35 no.3
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    • pp.58-63
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    • 2020
  • At the construction site of the driving site, the pile rebound and penetration measurements are performed manually to determine the end point of the driving operation, thereby causing the measurer to be exposed to a death accident. In this study, in order to eliminate the risk of this work, a non-contact penetration measuring device was developed and usability evaluation was conducted. The penetration measuring device is manufactured based on the ultrasonic sensor, and can be combined with the pile to deliver the data in real time, and the delivered data can be output in real time on the portable PC and the final penetration can be calculated. Usability evaluation on the device was conducted by comparison with manual work. Usability evaluation was largely evaluated on measured values, subjective comfort, and body parts comfort. The result of the measured value tended to overestimate the value measured manually by the measuring device, which is similar to the previous research. In terms of subjective comfort and body part comfort, overall satisfaction was higher than the manual method when using the measuring device. Taken together, these results indicate that it is possible to use the rudder measuring device in place of manual work in the construction site, and it is judged that the worker's comfort is greatly increased by using the measuring machine. The results of this study suggest that the use of non-contact measuring device in the field can be used as basic data to support them.