• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.204-211
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• 2009

In this study, the optimal method is applied to strengthening of RC hollow slab bridges using external prestressing. The Queen-post and King-post shapes are considered to find the effective tendon configurations. In order to achieve the objective rating factor, the optimal configurations and tendon forces are obtained by using the Sequential Unconstrained Minimization Technique (SUMT). The object function for optimal strengthening is constituted with the dimensionless function of material costs. The constraints are formulated by design specification and the rating factor. The validity of this study is presented by the analysis of the results of strengthening of the RC hollow slab bridges.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2192-2204
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• 2011

Recently, The government is actively transit road-oriented Traffic System to the eco-friendly and high-efficiency railroad-oriented transportation system for the sustainable green growth. The second plan of Nationwide Railway Network which has been officially announced rearrange to integration, multi-core, open architecture country by the railway network and integrate to the one mega city that rink an important city in one hour 30 minute. But the railroad industry is disadvantageous when it compares with the road industry on the ground that railroad industry peculiarities(a cost-benefit analysis, an environment value, etc) have not reflected in the (preliminary) feasibility study for SOC industry. The government establish Improved methodology of Rail Investment Rating System and improved preliminary feasibility study in railroad project by introduction many content(analysis periods, rate of discount, the benefits of shortening of transit hours, the estimation of traffic accident reduction benefits, investment cost of vehicle substitution and operation and maintenance cost of high speed rail) about the Improved methodology of Rail Investment Rating System. This study is intended to consideration the key content that was included in the Improved methodology of Rail Investment Rating System. In addition, the points to be considered for additional study have been reviewed in this study. We hope we will carry out make a reasonable and objective Rail Investment Rating System and to perform the railway industry of the virtuous cycle such improvement plans are reflected at a hereafter railroad section.

• Journal of Korea Water Resources Association
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• v.48 no.10
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• pp.807-816
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• 2015

In general, the water stage-discharge relationship curve is established based on the assumptions of linearity and homoscedasticity. However, the relationship between the water stage and discharge is affected from geomorphological factors, which violates the basic assumptions of the water stage-discharge relationship curve. In order to reduce the error due to the violations, the curve is divided into several sections based on the manager's judgement considering change of cross-sectional shape. In this research, the objective-splitting criteria of the curve is proposed based on the measured data without the subjective decision. First, it is assumed that the coefficient of variation follows the normal distribution. Then, if the newly calculated coefficient of variation is outside of the 95% confidential interval, the curve is divided. Namely, the groups is divided by the characteristics of the coefficient of variation and the reasonable criteria is provided for establishing a multi-segmented rating curve. To validate the proposed method, it was applied to the data generated by three artificial power functions. In addition, to confirm the applicability of the proposed method, it is applied to the water stage and discharge data of the Muju water stage gauging station and Sangegyo water stage gauging station. As a result, it is found that the automatically divided rating curve improves the accuracy and extrapolation accuracy of the rating curve. Finally, through the residual analysis using Shapiro-Wilk normality test, it is confirmed that the residual of water stage-discharge relationship curve tends to follow the normal distribution.

• Physical Therapy Rehabilitation Science
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• v.2 no.2
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• pp.99-103
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• 2013

Objective: Clinical measures that quantify upper extremity function are needed for the accurate evaluation of patients and to plan an intervention strategy. The purpose of this study was to examine the relationship between the Unified Parkinson's Disease Rating Scale (UPDRS)-Motor Exam and upper extremity performance as a quantifying clinical tool of upper extremity function in persons with Parkinson's disease. Design: Cross-sectional study. Methods: Thirty-two idiopathic Parkinson's Disease persons participated in this study. To investigate the relationship between the UPDRS-motor exam, Box and Block test (BBT), and Action Research Arm Test (ARAT) by two physical therapists. The examination took up to 1 hour, and the participants were invited to rest between each clinical measure in order to minimize the effects of fatigue. Clinical measures were assessed while the subjects were in the "on" phase of their medication cycle, generally 1-3 hour after taking their anti-Parkinson's medications. Results: In more affected side, the UPDRS-motor exam was significantly negative correlated with the BBT (p<0.05) but it was not significantly correlated with the ARAT. In less affected side, only positively correlation was significantly shown between BBT and ARAT (p<0.05). On the other hand, between BBT and ARAT were not significantly correlated with the UPDRS-motor exam. Conclusions: The UPDRS-motor exam is effective tool which was significantly correlated with manual dexterity in more affected upper extremity. But The UPDRS-motor exam is not effective tool in less affected upper extremity.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.15 no.2
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• pp.152-159
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• 2004

Objective : The present study investigated the interpretation bias and expectation and judgemental bias of performance in socially anxious children. Method : Children with high social anxiety (n=18) and low social anxiety (n=16) were recruited through self-report and peer nomination, Participants performed three tasks to assess for cognitive bias. The first task measured interpretation of ambiguous social situations. The second task measured expectations regarding performance in a three minute impromptu speech. The third task assessed for judgemental bias via comparison between post-speech self rating and observer rating. Result : Children with high social anxiety did not differ significantly from low social anxiety children on the dependent measures assessing bias in interpretation, expectation and judgement. However, a significant difference was found in the judges' rating of children's performances on the speech task, with high social anxiety children obtaining significantly lower scores compared to low social anxiety children. Conclusion : The role of cognitive biases in the development and maintenance of social anxiety in children was discussed.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.87-92
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• 1996

This paper formulates dynamic optimization model for Time-Of-Use Rates when a electric power system consists of three generators and a rating period is divided into three sub-periods. We use Pontryagin's Maximum Principle to derive optimal price and investment policy. Particularly the cross-price elasticities of demand are considered in the objective function. We get the following results. First, the price is equal to short-run marginal cost when the capacity is sufficient. However, if the capacity constraint is active, the capacity cost is included in the price. Therefore it is equal to the long-run marginal cost. Second, The length of rating period affects allocation of capacity cost for each price. Third, the capacity investment in dynamic optimization is proportional to the demand growth rate of electricity. However the scale of investment is affected by not only its own demand growth rate but also that of other rating period.

• The Journal of Korean Medicine
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• v.31 no.1
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• pp.47-56
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• 2010

Objective: Many drug or non-drug therapies are reported to be effective in reducing the severity of attention deficit/hyperactivity disorder (ADHD). The aim of this study was to assess the effect of color and pattern on the severity of ADHD in young ADHD patients. Method: We randomly assigned 30 children into two groups and had them participate in 15-minute block play sessions once in a week. The experimental group used blocks with green (3G, Munsell color system) circle patterns on them, while the control group played with plain white blocks. We also provided a set of playing cards with the corresponding patterns. This trial continued for 4 weeks and 29 children (96.7%) completed. The primary outcome measurement was the ADHD rating scale-IV and was evaluated on every visit. Results: After the trial, ADHD score decreased in both groups but not significantly ($34.4{\pm}8.0$ to $30.0{\pm}4.3$; $34.0{\pm}6.0$ to $30.3{\pm}3.2$). However, there were significant differences in 4 items of ADHD rating scale between the two groups. These consisted of 3 inattention (Q3, Q7, Q15) and 1 hyperactivity-impulsivity (Q12) items and the reduction between the first and final visits was significant (p=0.0240, p=0.0498, p=0.0237 and p=0.0012 respectively). Conclusion: Repeated exposure to a green circle pattern might not influence the total score of ADHD rating scale but reduced 3 inattention items and 1 hyperactivity-impulsivity significantly in children with ADHD. Proper visual stimuli are partially helpful for pediatric ADHD.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.671-681
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• 2011

Objective: The purpose of this study is to compare the workload level at each lower limbs posture and suggest the ergonomic workstation guideline for working period by evaluating the imbalanced lower limbs postures from the physiological and psychophysical points of view. Background: Many workers like welders are working in various imbalanced lower limbs postures either due to the narrow working conditions or other environmental conditions. Method: Ten male subjects participated in this experiment. Subjects were asked to maintain 3 different lower limbs postures(standing, squatting and bending) with 3 different working conditions(balanced floor with no scaffold, imbalanced floor with 10cm height of scaffold, and imbalanced floor with 20cm height of scaffold). EMG data for the 4 muscle groups(Retus Femoris, Vastus Lateralis, Tibialis Anterior, Gastrocnemius) from each lower limbs posture were collected for 20 seconds every 2 minutes during the 8 minutes sustaining task. Subjects were also asked to report their discomfort ratings of body parts such as waist, upper legs, lower legs, and ankle. Results: The ANOVA results showed that the EMG root mean square(RMS) values and the discomfort ratings(CR-10 Rating Scale) were significantly affected by lower limbs postures and working time(p<0.05). The correlation was analyzed between the EMG data and the discomfort ratings. Also, prediction models for the discomfort rating for each posture were developed using physical condition, working time, and scaffold height. Conclusion: We strongly recommend that one should not work more than 6 minutes in a standing or squatting postures and should not work more than 4 minutes in a bending posture. Application: The results of this study could be used to design and assess working environments and methods. Furthermore, these results could be used to suggest ergonomic guidelines for the lower limbs postures such as squatting and bending in the working fields in order to prevent fatigue and pain in the lower limbs body.

• Safety and Health at Work
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• v.8 no.4
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• pp.364-370
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• 2017

Background: Labeled noise reduction (NR) data presented by manufacturers are considered one of the main challenging issues for occupational experts in employing hearing protection devices (HPDs). This study aimed to determine the actual NR data of typical HPDs using the objective fit testing method with a microphone in real ear (MIRE) method. Methods: Five available commercially earmuff protectors were investigated in 30 workers exposed to reference noise source according to the standard method, ISO 11904-1. Personal attenuation rating (PAR) of the earmuffs was measured based on the MIRE method using a noise dosimeter (SVANTEK, model SV102). Results: The results showed that means of PAR of the earmuffs are from 49% to 86% of the nominal NR rating. The PAR values of earmuffs when a typical eyewear was worn differed statistically (p < 0.05). It is revealed that a typical safety eyewear can reduce the mean of the PAR value by approximately 2.5 dB. The results also showed that measurements based on the MIRE method resulted in low variability. The variability in NR values between individuals, within individuals, and within earmuffs was not the statistically significant (p > 0.05). Conclusion: This study could provide local individual fit data. Ergonomic aspects of the earmuffs and different levels of users experience and awareness can be considered the main factors affecting individual fitting compared with the laboratory condition for acquiring the labeled NR data. Based on the obtained fit testing results, the field application of MIRE can be employed for complementary studies in real workstations while workers perform their regular work duties.

• Anxiety and mood
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• v.17 no.2
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• pp.73-77
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• 2021

Objective : The Hoarding Rating Scale-Self-Report (HRS-SR) is a five-item scale that simply assesses the hoarding symptoms. We evaluated the factor structure, reliability, and validity of the Korean version of the HRS-SR (HRS-SR-K). Methods : A total of 144 individuals completed the self-administered questionnaires including HRS-SR-K, Obsessive-Compulsive Inventory-Revised-Korean version (OCI-R-K), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). Psychometric properties of the HRS-SR-K were analyzed. Results : The Cronbach's α value for internal consistency of the HRS-SR-K was excellent (Cronbach's α=0.84). The construct validity was analyzed on the basis of principal component analysis and one-factor structure of the original scale was maintained. The HRS-SR-K total score and each item scores were more strongly correlated with the hoarding subscale score in OCI-R-K (convergent validity, r=0.71, p<0.01) than the corresponding scores of nonspecific depression or anxiety measures (discriminant validity). Conclusion : The HRS-SR-K is a simple and reliable self-report scale for examining the severity of hoarding symptoms.