• 제목/요약/키워드: underestimation

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Debt Issuance and Capacity of Korean Retail Firms (유통 상장기업들의 부채변화에 관한 연구)

  • Lee, Jeong-Hwan;Son, Sam-Ho
    • Journal of Distribution Science
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    • v.13 no.9
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    • pp.47-57
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    • 2015
  • Purpose - The aim of this paper is to investigate the explanatory power of the Pecking-order theory (the cost of financing increases with asymmetric information) among Korean retail firms from the perspective of debt capacity. According to the Pecking-order theory, a firm's first preference is to use internal funds for its capital needs, its next preference is the issuance of debt, and its last preference is the issuance of equity; this is due to the information asymmetry problem between existing shareholders and investors. However, prior empirical studies, such as Lemmon and Zender (2010), argue that the entire sample test for the Pecking-order theory could be misleading due to the different levels of debt issuance capability of each of the individual firms; in fact, they confirm that the explanatory power of the Pecking-order theory improves after taking into account the differences in debt capacity of the U.S. firms they examined. This paper implements a case study approach among Korean retail firms to examine the relationship between debt capacity and the explanatory power of the Pecking-order theory in Korea. Research design, data, and methodology - This study uses the sample of public retail firms on the Korea Composite Stock Price Index (KOSPI) from the time period of 1990 to 2013. We gather related financial and accounting statements from the financial information firm WISEfn. Credit rating information is provided by the Korea Investor Service. We employ the models of Lemmon and Zender (2010) and Son and Kim (2013) to measure a firm's debt capacity. Their logit models use the rating dummy variable as a dependent variable and incorporate other firm characteristics as independent variables to estimate debt capacity. To test the Pecking-order theory, we adopt variants of the financing deficit model of Shyam-Sunder and Myers (1999). In the test of the Pecking-order theory, we consider all of the changes in total debt obligations, current debt obligations, and long-term debt obligations. Results - Our main contribution to the literature is our confirmation of the predicted relationship between debt capacity and the explanatory power of the Pecking-order theory among Korean retail firms. The coefficients on financing deficits become greater as a firm's debt capacity improves. This is consistent with the results of Lemmon and Zender (2010). The coefficients on the square of the financing deficits are also negative for the firms in the largest debt capacity group, which is also consistent with the predictions in prior literature. Conclusions - This study takes a case study approach by examining Korean retail firms. We confirm that the Pecking-order theory explains the capital structure of retail firms more appropriately, after taking into account the debt capacity of each firm. This result suggests the importance of debt capacity consideration in the testing of the Pecking-order theory. Our result also implies that there has been a potential underestimation of the explanatory power of the Pecking-order theory in existing studies.

Weight Control Behaviors, Health-related Quality of Life and Nutritional Status by Overestimation of Body Image among Young Korean Females: Data from the Fifth Korea National Health and Nutrition Examination Survey, 2010-2011 (20·30대 여성의 체형 과대인식에 따른 체중조절행위, 삶의 질, 식행동 및 영양소 섭취상태: 2010-2011년 국민건강영양조사 자료 이용)

  • Park, Seulki;Hyun, Taisun;Lee, Hongmie
    • Korean Journal of Community Nutrition
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    • v.20 no.5
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    • pp.362-374
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    • 2015
  • Objectives: This study was performed to investigate the effects of overestimation of their own body shape on weight control behaviors, mental condition, physical activity, dietary behavior, health-related quality of life, and nutritional status among young Korean females. Methods: A total of 1,514 women aged 20-39 years who are not pregnant and lactating among those who participated in the Fifth Korea National Health and Nutrition Examination Survey (2010~2011), were analyzed and grouped into underestimation (n=120), normal estimation (NE, n=840), and overestimation (OE, n=554), based on their body perception compared to actual percent ideal body weights. Variables were compared between OE group and NE group. Results: The subjects in OE group were significantly younger (29.5 vs. 30.5 years, respectively p < 0.05) and had lower body mass index (20.9 vs. 22.2 respectively, p < 0.01), health-related quality of life measured by EQ-5D (EuroQol-5 Dimension)(0.97 vs. 0.98 respectively, p < 0.05), nutrition adequacy ratio (NAR) of protein (0.91 vs. 0.93 respectively, p < 0.05), phosphorous (0.93 vs. 0.96 respectively, p < 0.05), and iron (0.70 vs. 0.75 respectively, p < 0.01), and index of nutrition quality (INQ) of iron (0.84 vs. 0.89 respectively, p < 0.05) compared to those in the NE group. The results of logistic regression showed that unmarried status (OR 1.32; 1.01~1.72) and severely underweight/underweight status (OR 1.94; 1.01~3.75)/(OR 1.81; 1.34~2.45) were significantly related to the probability of overestimation by the subjects. Significantly more women in OE group practiced fasting, skipping meals, and taking prescribed pills to lose body weights and had skipped breakfast compared to those in the NE group. Conclusions: The results of this study suggested that the Korean young women's distorted perception of own body shape may be associated with undesirable weight control behavior, low quality of life, and lower nutritional status. Therefore, nutrition education for this group should include information on correct body shape perception and its importance.

The Effect of Social Discount Rate Manipulation on the Economic Feasibility Tests: Focusing on the Environmental Public Investment Projects (사회적할인율 조정이 공공투자사업의 경제성 평가에 미치는 영향: 환경투자사업을 중심으로)

  • Kim, Sang Kyum
    • Journal of Environmental Policy
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    • v.12 no.4
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    • pp.71-92
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    • 2013
  • Unlike general public investment projects, when it comes to environmental public investment projects, there is a gap between those who pay the costs, and those who receive the benefits. This is because of the long term nature of environmental investments, which entails that the majority of the costs are paid by the current generation, while the benefits are reaped by future generations. Because of this, when the social discount rate is set at a standard, singular rate, an issue of relative underestimation of the benefits reaped by future generations may occur during the analytic process. This paper begins with the recognition of this problem, and attempts to estimate a suitable social discount rate that can be applied to environmental investment projects. Taking into account recent economic situations, the social discount rate is currently being estimated at between 2.9 ~ 4.9%. Also, this paper used preliminary feasibility studies that took place so far, to analyze the standard pattern of benefit generation. This revealed that alterations in social discount rates can bring significant changes in economic feasibility test results. Simulation results showed that roughly 6% of B/C ratios could be increased by 1%p. resulting in a decrease in social discount rates. Also if we use hyperbolic discount rates, instead of using the current singular rate, there would be a meaningful increase in the benefits for the future generation.

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A Case Study on Quantifying Uncertainties of Geotechnical Random Variables (지반 확률변수의 불확실성 정량화에 관한 사례연구)

  • Han, Sang-Hyun;Yea, Geu-Guwen;Kim, Hong-Yeon
    • The Journal of Engineering Geology
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    • v.22 no.1
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    • pp.15-25
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    • 2012
  • Probabilistic design methods have been used as a design standard in Korea and abroad for achieving reasonable design by considering the statistical uncertainties of soil properties. In this study, the following techniques for reflecting geotechnical uncertainty are analyzed: quantification of the uncertainties of geotechnical random variables, and consideration of economic feasibility in design by minimizing the uncertainties related to the number of samples. To quantify the uncertainties, the techniques were applied to soil properties obtained from samples collected and tested in the field. The results showed an underestimation of the standard deviation by the 3-sigma approach in comparison with calculations using data from the samples. This finding indicates that economical design is possible in terms of probability. However, when compared with the Bayesian approach, which does not consider the number of samples, variability in the 3-sigma approach is underestimated for some variables. This finding also indicates a safety issue, whereas the number of samples based on the Bayesian approach showed the lowest variance. The variance of the probability density function showed a marked decrease with increasing number of samples, to converge at a certain level when the number exceeds 25. Of note, the estimation of values is more reliable for random variables having low variability, such as soil unit weight, and can be obtained with a small number of samples.

A Segment-based Minimum Cutset Method for Estimating the Reliability of Water Distribution Systems (상수관망의 신뢰도 산정을 위한 Segment 기반의 Minimum Cutset 방법)

  • Jun, Hwan-Don;Park, Jae-Il;Baek, Chun-Woo;Kim, Joong-Hoon
    • Journal of Korea Water Resources Association
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    • v.40 no.9
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    • pp.735-742
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    • 2007
  • In this study, a methodology which is based on segments and minimum outsets to estimate the reliability of a real water distribution system efficiently and accurately is suggested. The current reliability assessment models based on minimum cutset consider a pipe as only area impacted by a pipe failure which incurs underestimation of pipe failure impact. In contrary, the suggested methodology adopts "segment" and "unintended isolation" with the hydraulic pressure failure area to define the actual service interruption area in a water distribution system due to a pipe failure, which is different from the Previous reliability estimating methodologies. In addition, a minimum cutset is defined as a single segment incurring abnormal operating conditions and the success mode approach is used to account for the probability of multiple failure combinations of minimum outsets. The model considers numbers and locations of on-off valves when the service interruption area is defined. Once the methodology is applied to a real water distribution system, it is possible to define actual service interruption areas and using the defined areas, the reliability of the water distribution system is estimated reliably, compared with the previous reliability assessment methodologies.

Turbid water atmospheric correction for GOCI: Modification of MUMM algorithm (GOCI영상의 탁한 해역 대기보정: MUMM 알고리즘 개선)

  • Lee, Boram;Ahn, Jae Hyun;Park, Young-Je;Kim, Sang-Wan
    • Korean Journal of Remote Sensing
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    • v.29 no.2
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    • pp.173-182
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    • 2013
  • The early Sea-viewing Wide Field-of-view Sensor(SeaWiFS) atmospheric correction algorithm which is the basis of the atmospheric correction algorithm for Geostationary Ocean Color Imager(GOCI) assumes that water-leaving radiances is negligible at near-infrared(NIR) wavelengths. For this reason, all of the satellite measured radiances at the NIR wavelengths are assigned to aerosol radiances. However that assumption would cause underestimation of water-leaving radiances if it were applied to turbid Case-2 waters. To overcome this problem, Management Unit of the North Sea Mathematical Models(MUMM) atmospheric correction algorithm has been developed for turbid waters. This MUMM algorithm introduces new parameter ${\alpha}$, representing the ratio of water-leaving reflectance at the NIR wavelengths. ${\alpha}$ is calculated by statistical method and is assumed to be constant throughout the study area. Using this algorithm, we can obtain comparatively accurate water-leaving radiances in the moderately turbid waters where the NIR water-leaving reflectance is less than approximately 0.01. However, this algorithm still underestimates the water-leaving radiances at the extremely turbid water since the ratio of water-leaving radiance at two NIR wavelengths, ${\alpha}$ is changed with concentration of suspended particles. In this study, we modified the MUMM algorithm to calculate appropriate value for ${\alpha}$ using an iterative technique. As a result, the accuracy of water-leaving reflectance has been significantly improved. Specifically, the results show that the Root Mean Square Error(RMSE) of the modified MUMM algorithm was 0.002 while that of the MUMM algorithm was 0.0048.

Assessment of Radiation Dose Due to X-Ray Simple Series Examinations (X-선 단순 Series 촬영 시 피폭 선량 평가)

  • Gang, Eunbo;Hwang, Incheol;Shin, Woonjae
    • Journal of the Korean Society of Radiology
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    • v.8 no.2
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    • pp.81-88
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    • 2014
  • In diagnostic radiology, each part is examined through serial radiography in most cases of general radiography. However, the reality is that, as for diagnostic reference level, measured values have been set up only for AP projection of each part and lateral projection. In the clinical setting, cumulative dose is incurred by serial radiography of patients, and this can make comparison of diagnostic reference level and cumulative exposure dose impossible or can lead to underestimation of diagnostic reference level. In this study, measurement of cumulative dose of serial radiography of each part revealed that when converting entrance surface dose to effective dose in case it is included in the exposure field, cumulative dose measured from a maximum of 38.06% to a minimum of 0.23% of individual dose limitation of the public. Also, when converting entrance surface dose of each part that is not included in the exposure field into effective dose, it measured from a maximum of 5% to a minimum of 0.04% of individual dose limitation of the public. Results of this study show entrance surface dose substantially increases in serial radiography of each part. Therefore, it is deemed that hospitals need to establish diagnostic reference level specifically, and subdivision of radiography orders for patients is also required in order to reduce unnecessary inspections. Moreover, the need of accurate exposure field is emphasized in case of inspection of several parts.

A Study on the Optimal Sampling for Predicting Failure Rate of One-Shot Weapon Systems (원샷 무기체계 고장률 예측을 위한 최적 샘플링 방안 연구)

  • Ahn, Joo Han;Ma, Jungmok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.366-372
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    • 2020
  • The Army's rocket missile is a one-shot weapon system, which is produced and used for only one mission, and requires high reliability. While reliability analysis with failure data can result in underestimation of the life distribution, reliability analysis with all the non-failure data can result in overestimation of the life distribution. Under or overestimation of the life distribution can lead to cost increase by early disposal or complete observation of all rocket missiles. In order to overcome this problem, the Army suggests the guideline of the number of samples from non-failure data for reliability analysis with failure data. However, the currently used sampling method can generate errors for predicting the failure rate. To solve this problem, this study proposes a new sampling procedure for predicting a future failure rate using non-failure data. The comparison test between the currently used sampling method and the proposed sampling method is conducted and the result shows that the proposed sampling method can predict the future failure rate more accurately.

Symptom severity, Functional Impairment, and Personality Profiles between Partial and Full Post-traumatic Stress Disorder Patients among the Adolescent Survivors from the Incheon Fire Disaster (인천 화재사건 청소년 생존자를 대상으로 한 PTSD 하위유형간 증상, 기능 및 기질성격 특성 비교연구)

  • Hwang, Seo Hyun;Lee, Hong Seock;Lee, Sang Kyu;Lee, Heung Pyo;Jeon, Chul Eun;Lee, So Young;Lee, Yong Ku
    • Anxiety and mood
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    • v.7 no.2
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    • pp.92-100
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    • 2011
  • Objectives : The aim of this study was to investigate Post Traumatic Stress Disorder (PTSD)-related symptom severity, level of functional impairment and personality profiles between full-blown PTSD, partial PTSD and non-PTSD groups among 59 adolescent survivals from the Incheon fire disaster. Method : Using Short Screening Scale for DSM-IV PTSD, victims of the disaster were assigned to a full-blown PTSD group (n=18), a partial PTSD (n=22), or a non-PTSD group (n=19). Assessments included the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), the Impact of Event Scales (IES), the McBride's Degree of General Labor Loss, and the Korean Version of Temperament and Character Inventory (K-TCI). Results : Significantly severe PTSD symptoms (F=4.832, df=2, p<.05) and functional impairment (F=12.144, df=2, p<.01) were demonstrated by PTSD groups as compared to the non-PTSD group. Interestingly, full and partial PTSD did not differ in these comparisons. Similarly, the subtypes of PTSD did not differ with respect to personality profiles using the K-TCI ; however, personality profiles were sharply differentiated between the PTSD and non-PTSD group. Conclusion : Although high subject homogeneity and small sample size may limit the results of this study, the present results highlight the possibility of the underestimation as well as the insufficient, treatment and compensation of partial vs full PTSD.

Analysis of the Inequalities in Healthcare Service Usage Considering Healthcare Service Needs (의료필요를 고려한 의료이용의 형평성 분석)

  • Lee, Yong-Jae;Lee, Hyun-Ok;Kim, Hyung-Eick
    • The Journal of the Korea Contents Association
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    • v.17 no.11
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    • pp.435-445
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    • 2017
  • This study was conducted to overcome the limitations of prior research on the equity of medical care performed by identifying simple differences in the use of medical care or using limited medical needs and medical utilization indicators. Specifically, we used activity limits, chronic diseases, and subjective health status as medical needs, and used outpatient, inpatient, and emergency services as medical uses. In addition, we used concentration index, concentration curve, and Le Grand factor to analyze the equity of medical use considering medical needs. The main results are as follows. First, the amount of medical care for the low-income class is higher than that of the high-income class when considering the concentration of medical use. In particular, the number of hospitalization days for low-income households and hospitalization fees were higher than the fees of outpatient medical consultation and emergency room usage. Second, medical needs were concentrated in the low income class. In other words, low-income group is not as healthy as the high-income group. Third, the Le Grand factor was calculated in order to confirm the fairness of the medical uses considering the medical needs. Even if medical needs are taken into consideration, the high-income earners will have a large amount of medical care. In addition, when considering the limitation of activity and the number of chronic diseases, the medical use of the high income class was more frequent. However, when the subjective health condition and the chronic illness were considered, medical use of the low income class was more frequent. This may be due to the underestimation of the medical needs of the low-income earners by neglecting their own health status and perception of chronic diseases.