• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.63-69
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• 1999

The research trend of the simulation optimization has been focused on exploring continuous decision variables. Yet, the research in discrete decision variable area has not been fully studied. A new research trend for optimizing discrete decision variables ha just appeared recently. This study, therefore, deals with a discrete simulation method to get the system evaluation criteria required for designing a complex probabilistic discrete event system and to search the effective and reliable alternatives to satisfy the objective values of the given system through a on-line, single run with the short time period. Finding the alternative, we construct an algorithm which changes values of decision variables and a design alternative by using the stopping algorithm which ends the simulation in a steady state of system. To avoid the loss of data while analyzing the acquired design alternative in the steady state, we provide background for estimation of an auto-regressive model and mean and confidence interval for evaluating correctly the objective function obtained by small amount of output data through simulation with the short time period. In numerical experiment we applied the proposed algorithm to (s, S) inventory system problem with varying Δt value. In case of the (s, S) inventory system, we obtained good design alternative when Δt value is larger than 100.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.135-143
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• 2005

The shoes process management monitoring system for supporting SCM is developed in this study. This system consists of a monitoring program, a conveyer system, a pneumatic unit, a controller, an USB camera, and a server and a client computer. To operate the developed system easily, the monitoring program using LabVIEW in the Windows environment is developed. This program consists of 5 modules: production management, inventory control, media management, defective management, and communication management. The developed system has several advantages: reduced time for managing process work, decreased labor costs, effective operation, and continuous work without an operator. Nowadays advanced manufacturing companies are trying to find a way to check the performance of their production equipments and plants from remote sites. Thus, to manage the developed system from remote sites, communication network is constructed. In order to evaluate the performance of the monitoring system, experiments were performed. The experimental results showed that the developed system provided a reliable performance and a stable communication.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.1
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• pp.113-121
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• 2021

A safety assessment of radioactive waste repositories is a mandatory requirement process because there are possible radiological hazards owing to radionuclide migration from radioactive waste to the biosphere. For a reliable safety assessment, it is important to establish a parameter database that reflects the site-specific characteristics of the disposal facility and repository site. From this perspective, solubility, a major geochemical parameter, has been chosen as an important parameter for modeling the migration behavior of radionuclides. The solubilities were derived for Am, Ni, Tc, and U, which were major radionuclides in this study, and on-site groundwater data reflecting the operational conditions of the Gyeongju low and intermediate level radioactive waste (LILW) repository were applied to reflect the site-specific characteristics. The radiation dose was derived by applying the solubility and radionuclide inventory data to the RESRAD-OFFSITE code, and sensitivity analysis of the dose according to the solubility variation was performed. As a result, owing to the low amount of radionuclide inventory, the dose variation was insignificant. The derived solubility can be used as the main input data for the safety assessment of the Gyeongju LILW repository in the future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.77-85
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• 2004

Regulations and guidelines for radioactive waste disposal require detailed information about the characteristics of radioactive waste drums prior to transport to the disposal sites. However, estimation of radionuclide concentrations in the drummed radioactive waste is difficult and unreliable. In order to overcome this difficulty, scaling factor (SF) method has been used to assess the activities of radionuclides, which could not be directly analyzed. A radioactive waste assay system has been operated at Korean nuclear power plant (KORI site) since 1996 and consolidated SF concept has played a dominant role in the determination of radionuclide concentrations. However, SFs are somewhat dispersive and limited in KORI site. Therefore establishment of the assay system using more improved SFs is planned and progressed. In this paper, the scope of research is briefly introduced. For the selection of more reliable activity determination method, the accuracy of predicted SF values for each activity determination method is compared. From the comparison of each activity determination method, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system. And, this change of SF determination method will prevent an inordinate over-estimation of radionuclide inventory in radwaste drum.

• Korean Journal of Social Welfare
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• v.66 no.3
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• pp.253-276
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• 2014

The purpose of the present study was to examine psychometric properties of the BSI-18 in Korean adults with mental disorders. This study examined internal consistency, test-retest reliability, convergent validity, and a factor structure of the BSI. The sample consisted of 180 adults with mental disorders, who enrolled in mental hospitals and in a day hospital. Data was analysed using reliability analysis, correlation analysis, and confirmatory factor analysis. Major findings were as follows. The Korean version of the BSI showed good internal consistency and test-retest reliability, as well as excellent convergent validity. The original three-factor structure of the BSI-18, proposed by Derogatis, 2001, fitted to the data. These findings indicate that the BSI-18 is a reliable and valid measure as a psychiatric assessment tool and a treatment outcome measure.

• The Journal of Korean Physical Therapy
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• v.26 no.2
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• pp.90-96
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• 2014

Purpose: The aim of the study was to develop the Korean version of the Working Alliance Inventory (KWAI) and to assess reproducibility of both its therapist and client forms. Methods: The 12-item WAI was translated into Korean. The translation procedure followed the guidelines proposed by Beaton et al. (2000). Development of KWAI involved its translation, back-translation, and pilot testing of the pre-final version to establish Korean cultural adaptation of the original version of WAI. For test-retest reliability, therapists (N=30) and clients (N=47) completed the questionnaire on two different occasions. The interval between occasions was two to seven days, depending on subject availability. Data were collected from clinicians working in general hospitals and private clinics, and clients who had received treatment within three months. The intra-class correlation (ICC ($_{2.1}$)) was calculated for assessment of the reproducibility of the translated questionnaire. Results: The test-retest ICC ($_{2.1}$) of the client form and the therapist form was 0.92 (95%CI:0.86-0.95) and 0.94 (95%CI:0.89-0.97), respectively. Answers to items 2, 8, and 11 showed a tendency to be omitted due to ambiguity of meaning in Korean. Idiomatic expression was employed rather than word-to-word translation to have clear meaning of those items. Conclusion: The KWAI was successfully translated and adapted for applications to Korean clients and therapists, with a satisfactory level of reliability. Therefore, it can be suggested that the KWAI is useful in providing a reliable assessment of working alliance between therapists and clients.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.73-78
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• 2016

Bhutanese forests have been well preserved and can sequester the atmospheric carbon (C). In spite of its importance, understanding Bhutanese forest C dynamics was very limited due to the lack of available data. However, forest C model can simulate forest C dynamics with comparatively limited data and references. In this study, we aimed to simulate Bhutanese forest C dynamics at 6 plots with the Forest Biomass and Dead organic matter Carbon (FBDC) model, which can simulate forest C cycles with small amount of input data. The total forest C stock ($Mg\;C\;ha^{-1}$) ranged from 118.35 to 200.04 with an average of 168.41. The C stocks ($Mg\;C\;ha^{-1}$) in biomass, litter, dead wood, and mineral soil were 3.40-88.13, 4.24-24.95, 1.99-20.31, 91.45-97.90, respectively. On average, the biomass, litter, dead wood, and mineral soil accounted for 36.0, 5.5, 2.5, and 56.0% of the total C stocks, respectively. Although our modeling approach was applied at a small pilot scale, it exhibited a potential to report Bhutanese forest C inventory with reliable methodology. In order to report the national forest C inventory, field work for major tree species and forest types in Bhutan are required.

• Journal of Educational Research in Mathematics
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• v.22 no.1
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• pp.69-99
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• 2012

This study aims to develop a highly-reliable inventory for measuring and analyzing the positive psychological experience in math learning. A measurement result provides meaningful information on the strength of students. Elements of positive psychological experience in math learning were extracted by the extensive research on the literature. The result was verified through the open survey. Through this process, the first preliminary questionnaire of 106 items was released, and was revised into the second one of 66 items through a continuous investigation on reliability and validity. Finally, a measurement inventory with 65 questions for testing 'positive psychological experience in math learning' was established.

• 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.

• Journal of The Geomorphological Association of Korea
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• v.26 no.3
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• pp.53-67
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• 2019

The purpose of this study is to identify the quality of landslide susceptibility in a landslide-prone area (Jinbu-myeon, Gangwon-do, South Korea) by spatial prediction modeling approach and compare the results obtained. For this goal, a landslide inventory map was prepared mainly based on past historical information and aerial photographs analysis (Daum Map, 2008), as well as some field observation. Altogether, 550 landslides were counted at the whole study area. Among them, 182 landslides are debris flow and each group of landslides was constructed in the inventory map separately. Then, the landslide inventory was randomly selected through Excel; 50% landslide was used for model analysis and the remaining 50% was used for validation purpose. Total 12 contributing factors, such as slope, aspect, curvature, topographic wetness index (TWI), elevation, forest type, forest timber diameter, forest crown density, geology, landuse, soil depth, and soil drainage were used in the analysis. Moreover, to find out the co-relation between landslide causative factors and incidents landslide, pixels were divided into several classes and frequency ratio for individual class was extracted. Eventually, six landslide susceptibility maps were constructed using the Bayesian Predictive Discriminant (BPD), Empirical Likelihood Ratio (ELR), and Linear Regression Method (LRM) models based on different category dada. Finally, in the cross validation process, landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract success rate curve. The result showed that Bayesian, likelihood and linear models were of 85.52%, 85.23%, and 83.49% accuracy respectively for total data. Subsequently, in the category of debris flow landslide, results are little better compare with total data and its contained 86.33%, 85.53% and 84.17% accuracy. It means all three models were reasonable methods for landslide susceptibility analysis. The models have proved to produce reliable predictions for regional spatial planning or land-use planning.