• 한국전문물리치료학회지
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• 제19권3호
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• pp.91-97
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• 2012

The primary aim of this study was to compare responsiveness of self-report by worker and therapist-scored functional capacity instrument. Self-report and therapist-scored interval-level person measures and item difficulties were compared at admission and discharge. Therapist and worker ratings were collected on 230 clients from 27 rehabilitation sites using the newly developed Occupational Rehabilitation Data Base (ORDB) functional capacity instrument. ORDB comprises several subscales measuring relevant variables of "a return-to-work model" in work-related rehabilitation clinics. The functional capacity scale deals with 10 DOT job factors. The rating scale categories were 1-severely impaired, 2-moderately impaired, 3-mildly impaired, and 4-not impaired. Only data from clients with low back pain (n=98) with complete data (both admission and discharge scores) were used for the present study. Therapists and workers completed the functional capacity instrument at admission and discharge. Rasch analysis [1-parameter item response theory model (IRT)] was applied to calibrate item difficulty and person ability measure of therapist and workers ratings. Effect sizes for therapist and self-report ratings were slightly different, .69 and .30, respectively. Therapist and worker ratings were more consistent at discharge (r=.54) than at admission (r=.32). Workers have a tendency to be more severe in their ratings (show higher item difficulties) than therapists at admission and discharge. Therapists and workers report similar magnitudes of improvement following treatment program. These findings challenge the belief that injured workers may unreliable source for monitoring therapeutic outcomes. Self-report measures have the advantage of conserving therapist time for treatment (versus evaluation). While the therapist and self-report ratings are comparable at discharge, there is less consistency at admission. Comparable therapist-worker ratings may be achieved by controlling for rating severity using IRT methodologies.

• 한국전문물리치료학회지
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• 제23권4호
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• pp.71-80
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• 2016

Background: Functional capacity evaluations (FCEs) are designed to systematically assess the capacity to perform work-related tasks and to determine worker's ability to return to the previous job following work-related injuries. These evaluations may be rated either by clinician or worker. There has been a lack of consensus between the two scoring methods. Objects: This study aimed: 1) to confirm if the data are fit to the Rasch rating scale model and 2) to investigate the item-level concordance rate between the ratings of clinician and injured worker of the FCE. Methods: A cross-sectional study was conducted with a sample (n=124) of a rehabilitation program with the Occupational Rehabilitation Data Base for workers with low back pain. The functional capacity evaluation at admission and discharge was administered to clinicians and workers. The data were analyzed using both classical test theory-based Pearson's r and intra-class coefficient followed by item-level analysis with Rasch rating scale model. Results: All items of the FCE, except sitting items rated by clinician at admission and handling items rated by both clinician and worker throughout admission and discharge, were acceptable fit statistics with minor out of ranges for a misfit criterion. This may indicate that the items of the FCE overall fit to the Rasch rating scale model. Few problematic items responding differently to clinician and worker both at admission and discharge were detected with the differential item functioning analysis despite the excellent concordance rate using the two conventional statistics-sitting and handling items at admission and handling item at discharge. Conclusion: The item-level speculations using Rasch analysis of the FCE demonstrate that the ratings of clinician and self ratings of worker were psychometrically acceptable though there was an apparent discrepancy between the raters both at admission and discharge.

• 전력전자학회논문지
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• 제9권4호
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• pp.341-349
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• 2004

본 논문에서는 전체 시스템의 용량 증대와 부하 중요도에 따른 신뢰성 향상을 위해 사용되는 UPS 병렬 운전시 발생하는 문제점을 해석하고, 이를 해결하기 위해 기존에 연구되어온 다양한 제어기법들을 조사하였다. 또한 기존의 연구방법에서 적용할 수 없었던 다른 정격의 병력 운전 적용시 L, C 출력필터에 의한 문제점을 해결하기 위해 주종 제어를 이용한 3상 UPS의 전류 분달 제어기법이 연구되었다. 제안된 제어 알고리즘의 타당성을 검증하기 위해 시뮬레이션 및 실험을 수행하였다.

• 대한간호학회지
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• 제23권4호
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• pp.678-693
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• 1993

The purposes of this study were to describe the level of vision and hearing impairments, depression and functional capacity, among Korean institutionalized elderly and to examine the relation-ship between sensory impairments, depression, and functional capacity in these people. The final pupose was to test the cognitive function path model using sensory competencies as predictors. A convenience sample of thirty nine male and 90 female subjects with a mean age of 80.5 were the subjects of this study. The subjects were tested for cognitive function, and vision and hearing impairments. Physical function and social function were measured by observation of designated task performance by the subjects. Their level of de-pression was measured using a Geriatric Depression Scale administered through an interview. Individual subjective ratings of hearing and vision were marked by the subjects, on a ladder scale. The results of the study showed that 48.8% of the subjects had a hearing impairment, 63.5% had a vision impairement, and 36.4% had both a vision and hearing impairement. The four sensory groups (no sensory impairement, hearing impairement, vision impairement, hearing and vision impairement) were tested for differences in depression, physical function, social behavior and cognitive function. The only significant difference that was found was in cognitive function, between the no sensory impairement group and the hearing and vision impairement group(F=3.25, P<.05), Subjective ratings of hearing showed a significant correlation with cognitive function(r=.34, p<.001) and with social behavior(r=.31, p<.001). There was no correlation between subjective vision ratings and cognitive function or social behavior. However there was a significant correlation between vision and hearing(r=.49, p<.001). There was also a significant negative correlation between age and vision(r=-.21, p<.01) and between age and hear-ing(r=-.34, p<.001). There was a significant correlation between depression and physical function (r=-.32, p<.001) but there was no correlation between depression and cognitive function or social behavior. Based on the literature review and the result, this study, a path model of sensory competence-> cognitive function- >social behavior was developed and tested : Perceived vision and perceived hearing were the exogenous variahles and cognitive function and social behavior were the endogeneous variables in the model. The path analysis result demonstrated an accept-able fit (GFI=.997, AGFI=.972, X$^2$=.72 (p=.396), RMSR=.019) between the data and the model. There was a significant direct effect($\beta$=.38) of perceived hearing on cognitive function. There was a significant direct effect ($\beta$=.32) of cognitive function on social behavior. The total effect of hearing on social behavior was $\beta$=.32 including the indirect effect ($\beta$=.12) . However perceived vsion had little effect ($\beta$=-.08) on cognitive function. The result of path analysis confirms that hearing levels influence cognitive function, and both hearing and cognitive function levels influence social behavior. However, vision has little effect on cognitive function or on social behavior. For the next study, a combined model of the pre viously developed environment - >depression- > physical and social function model, and the present cognitive function model, should be tested to further refine the functional capacity model. There also a need for longitudinal study of functional capacity and sencory competence in order to better understand how declining sensory competence influences functional capacity and how it effects in-creasing dependency and nursing needs in the elderly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.476-479
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• 2001

Interconnection of new energy sources, such as photovoltaic generation, wind power generation, etc., into the electric power distribution system may result in the increasing short-circuit capacity when a short circuit fault occurs. The short-circuit capacity becomes over the interrupting ratings of circuit breakers, and then they fails to operate in the proper way they prevent fault currents from flowing into the distribution facilities and thus causing them serious damages. This study deals with impacts on the respective short-circuit capacity of both low voltage and extra high voltage distribution systems at which new energy sources are installed. In order to obtain more accurate and all-case values very close to reality in the complicated distribution system, computer simulation tools should be required. In this paper, however, its focus is placed on examining the varying trend of short-circuit capacity, which may happen owing to new energy source interconnection, as a previewing step for exhaustive simulation studies.

• Structural Engineering and Mechanics
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• 제77권5호
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• pp.661-672
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• 2021

In this article, the role of spans number and length in fire-resistance ratings (FRRs) of fireproofed steel frames are investigated. First, over a span-lengthening scenario, two one- and three-bay frames under the ISO834 fire are examined. It is shown that the FRRs of the frames rely highly on the changes made on their span length. Second, a building designed for three spans number of three, four, and five under natural fire is investigated. The beams are designed for two load-capacity-ratios (LCRs) of optimum and ultimate. The fire curves are determined through a probabilistic-based approach. It is shown that the structural vulnerability vastly increases while the number of spans decreases. The results show that for an optimum LCR, while the five-span frame can meet the required FRR in 87% of the fire scenarios, the four- and three-span frames can meet the required FRR in only 56%, and 50% of the fire scenarios, respectively. For an ultimate LCR, the five-, four- and three-span frames can meet the required FRR in 81%, 50%, and 37.5% of the fire scenarios, respectively. Functional solutions are then proposed to resolve the insufficiencies in the results and to rectify the application of the standard-based FRRs in the cases studied. The study here highlights how employing current standard-based FRRs can endanger structural safety if they are not connected to structural characteristics; a crucial hint specifically for the structural engineering community who may be not well familiar with the fundamentals of performance-based approaches.

• Structural Engineering and Mechanics
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• 제47권5호
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• pp.643-660
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• 2013

In the present work, the capacity ratings of steel truss bridges have been carried out incorporating dynamic effect of moving vehicles and its accumulating effect as fatigue. Further, corrosion in the steel members has been taken into account to examine the rating factor. Dynamic effect has been considered in the rating procedure making use of impact factors obtained from simulation studies as well as from codal guidelines. A steel truss bridge has been considered to illustrate the approach. Two levels of capacity ratings- the upper load level capacity rating (called operating rating) and the lower load level capacity rating (called inventory rating) were found out using Load and Resistance Factor Design (LRFD) method and a proposal has been made which incorporates fatigue in the rating formula. Random nature of corrosion on the steel member has been taken into account in the rating by considering reduced member strength. Partial safety factor for each truss member has been obtained from the fatigue reliability index considering random variables on the fatigue parameters, traffic growth rate and accumulated number of stress cycle using appropriate probability density function. The bridge has been modeled using Finite Element software. Regressions of rating factor versus vehicle gross weight have been obtained. Results show that rating factor decreases when the impact factor other than those in the codal provisions are considered. The consideration of fatigue and member corrosion gives a lower value of rating factor compared to those when both the effects are ignored. In addition to this, the study reveals that rating factor decreases when the vehicle gross weight is increased.

• Asia Marketing Journal
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• 제25권1호
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• pp.37-44
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• 2023

Firm innovativeness and financing capacity are critical signals to stakeholders as they are key drivers of firm performance and competitiveness and indicate the firm's ability to fund its operations and growth initiatives. Based on signaling theory, this study investigates the signaling effect of a firm's innovativeness and creditworthiness and examines its signaling effectiveness. Using Korean innovation data and Korea Investors Service financial data for nine years, the findings indicate that a firm's technological innovation has a negative impact on its credit ratings, while non-technological innovation has a positive impact. Furthermore, a firm's credit ratings positively impact its performance. The current study contributes to the literature on signaling theory by exploring the signaling effect of a firm's innovativeness and creditworthiness. The findings provide insights for managers on how to send and monitor signals to stakeholders.

• 유통과학연구
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• 제13권10호
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• pp.73-82
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• 2015

Purpose - This paper aims to investigate whether information asymmetry could explain capital structures in Korean corporations. According to Myers (1984), firms prefer internal funding to external financing due to the costs associated with information asymmetry. When external financing is necessary, firms prefer to issue debt rather than equity by the same reasoning. Since Shyam-Sunder and Myers (1999), numerous studies continue to debate the validity of the theory. In this paper, we show how the theory depends on assumptions and incorporated variables. We hope our investigation can provide helpful implications regarding capital structure, information asymmetry, and other firm characteristics. Specifically, our empirical results are complementary to the analysis of Son and Lee's (2015), a recent study that examines the pecking order theory prediction for Korean retail firms. Research design, data, and methodology - We test empirical models that are some variants of model used in Shyam-Sunder and Myers (1999). The financial and accounting data are provided by WISEfn for the firms listed on the KOSPI during 1990 to 2013. Bond ratings are supplied by the Korea Investor Service (KIS). We take into account the heterogeneity in debt capacity; a firm's debt capacity is measured by using the method of Lemmon and Zender (2010) based on its bond ratings. Finally, we estimate empirical models suggested by Shyam-Sunder and Myers (1999), Frank and Goyal (2003), and Lemmon and Zender (2010). Results - First, we find that Shyam-Sunder and Myers' (1999) prediction fails to explain total debt changes of Korean firms. Second, we find a non-monotonic relationship between total debt changes and financial deficits with respect to debt capacity. This contradicts the prediction of Lemmon and Zender (2010) that argues the pecking order theory survives with a monotonically increasing relationship. Third, we estimate a negative correlation coefficient between financial deficit and current debt changes. The result is the complete opposite of the prediction of Lemmon and Zender (2010). Finally, we also confirm the non-monotonic relationship between non-current debt changes and financial deficits with respect to debt capacity. Yet, the slope of coefficient is smaller than that of total debt change case. Indeed, the results are, to some extent, consistent with the prediction of pecking order theory, if we exclude the mid-debt capacity firms. Conclusions - Our empirical results complementary to the analysis of Son and Lee (2015), a recent study focusing on capital structure in Korean retail firms; their paper suggests interesting topics regarding capital structure, information asymmetry, and other firm characteristics in Korean corporations. Contrary to Son and Lee (2015), our results show that total debt changes and current debt changes are inconsistent with the prediction of Shyam-Sunder and Myers (1999). However, similar to Son and Lee (2015), non-current debt changes are consistent with the pecking order prediction, in the case of excluding the mid-level debt capacity firms. This contrast allows us to infer that industry characteristics significantly affect the validity of the pecking order prediction. Further studies are needed to analyze the economics behind this phenomenon, which is beyond the scope of our paper. In addition, the estimation bias potentially matters regarding the firm-level debt capacity calculation. We also reserve this topic for future research.

• 한국강구조학회 논문집
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• 제24권3호
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• pp.349-360
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• 2012

본 논문은 GFRP 슬래브 교량 상부구조에 대한 장기성능, 내하력, 사용성 및 구조적 안전성의 상세한 평가를 기술하고 있다. 국내 최초로 완전 GFRP 슬래브 교량이 2002년 5월에 가설되었다. GFRP 슬래브 교량은 단순지지로 지간 10.0 m, 폭 8.0 m 인 2차선으로 설계되었다. 본 GFRP 슬래브교량은 콜루게이트(corrugate) 심재를 갖는 샌드위치 구조로서 유리섬유와 비닐 에스테르를 사용하여 수적층으로 제작되었다. GFRP 슬래브 교량의 장기성능 평가는 2002년 수행되었던 동일한 현장재하시험으로 2004, 2011년에 실시되었다. GFRP 슬래브교량은 예상되었던 대로 공용 중에서 구조적 문제점이 없이 성능이 잘 발휘되고 있었음을 평가를 통하여 나타내고 있다. 본 평가 자료는 GFRP 슬래브 교량의 내하력 평가에 대한 기초자료와 완전 GFRP 슬래브교량 상부구조의 장기성능의 일부자료로서 제공될 수 있을 것이다.