• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.762-769
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• 2018

This study was carried out to examine the improvement plan by analyzing the characteristics of imported wastes, operation rate, and benefits of energy recovery for incineration facilities with a treatment capacity greater than 50 ton/day. The incineration facility capacity increased by 3,280 tons over 15 years, and the actual incineration rate increased to 2,783 ton/day. The operation rate dropped to 76% in 2010 and then rose again to 81% in 2016. The actual calorific value compared to the design calorific value increased by 33.8% from 94.6% in 2002 to 128.4% in 2016. The recovery efficiency decreased by 29% over 16 years from 110.7% to 81.7% in 2002. Recovery and sales of thermal energy from the incinerator (capacity 200 ton/day) dominated the operation cost, and operating income was generated by energy sales (such as power generation and steam). The treatment capacity increased by 11% to 18% after the recalculation of the incineration capacity and has remained consistently above 90% in most facilities to date. In order to solve the problem of high calorific value waste, wastewater, leachate, and clean water should be mixed and incinerated, and heat recovery should be performed through a water-cooled grate and water cooling wall installation. Twenty-five of the 38 incineration facilities (about 70%) are due for a major repair. After the main repair of the facility, the operation rate is expected to increase and the operating cost is expected to decline due to energy recovery. Inspection and repair should be carried out in a timely manner to increase incineration and heat energy recovery efficiencies.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.159-176
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• 1991

The probability of target survival is the most important factor in the target assignment, Most of the studies about it have assumed the case of one target and ane weapon type. Therefore, they can not be applied to the real situation. In this paper. the quantity and type of enemy assets of the friendly force are considered simultaneously. Considered defense type is the coordinated defense with no impact point prediction. The objective function is to minimize the expected total survival value of targets which are scattered in the defense area. The rules of aircraft assignment are as follows : first, classify targets into several groups, each of those has the same desired damage level secondly. select the critical group which has the least survival value in accordance with the additional aircraft assignment, and finally. assign the same number of attack assets against each target in the critical group. In this paper, the attack assets, the escort assets, and the defense assets are considered. The model is useful to not only the simple aircraft assignment problem but also the complicated wargame models.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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• pp.295-308
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• 2000

OSMI(Ocean Scanning Multi-Spectral Imager) raw image data(Level 0) were acquired and radiometrically corrected. We have applied two methods, using solar & dark calibration data from OSMI sensor and comparing with the SeaWiFS data, to the radiometric correction of OSMI raw image data. First, we could get the values of the gain and the offset for each pixel and each band from comparing the solar & dark calibration data with the solar input radiance values, calculated from the transmittance, BRDF (Bidirectional Reflectance Distribution Function) and the solar incidence angle($\beta$, $\theta$) of OSMI sensor. Applying this calibration data to OSMI raw image data, we got the two odd results, the lower value of the radiometric corrected image data than the expected value, and the Venetian Blind Effect in the radiometric corrected image data. Second, we could get the reasonable results from comparing OSMI raw image data with the SeaWiFS data, and get a new problem of OSMI sensor.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.4
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• pp.466-475
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• 1999

A backward Dynamic Programming(DP) model for the optimal facility replacement decision problem during a finite planning horizon is presented. Multiple alternative challengers to a current defender are considered. All facilities are assumed to have finite service lives. The objective of the DP model is to maximize the profit over a finite planning horizon. As for the cost elements, purchasing cost, maintenance costs and repair costs as well as salvage value are considered. The time to failure is assumed to follow a weibull distribution and the maximum likelihood estimation of Weibull parameters is used to evaluate the expected cost of repair. To evaluate the revenue, the rate of operation during a specified period is employed. The cash flow component of each challenger can vary independently according to the time of occurrence and the item can be extended easily. The effects of inflation and the time value of money are considered. The algorithm is illustrated with a numerical example. A MATLAB implementation of the model is used to identify the optimal sequence and timing of the replacement.

• Journal of Information Technology Services
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• v.20 no.4
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• pp.23-33
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• 2021

The prolonged coronavirus 19 (COVID-19) has caused serious problems such as job losses and youth unemployment, but as the fourth industrial revolution and digital transformation accelerate, the importance of SW is highlighted and more qualified jobs are expected in the SW industry. However, domestic SW companies are having difficulties in not properly recognizing the value of SW products. Among many related issues, commercial SW maintenance-related issues are representative, and the main problem is the difference in the maintenance fee rates between domestic and foreign SW. In this study, the expected job creation effect when the SW maintenance rate is raised was analyzed using data related to the SW industry and commercial software. As a result of the analysis, the amount required to raise the commercial SW maintenance rate by 1% is 162 billion won. If all of these are used for employment, the expected new job creation effect is 3,240 jobs per year, and 15,451 jobs are created per year when calculated and estimated as the effect of increasing sales through the employment inducement coefficient. In addition, the amount required to raise the current average maintenance rate of 11.1% to 15% is 631.9 billion won, and it was possible to estimate the effect of creating jobs for 12,648 people based on the simple average wage and 60,259 people from the sales increase effect.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.197-205
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• 2019

The purpose of this research was examining the effects of problem-based learning strategies(PBL) on problem solving skill conducted in Korea, using meta-analysis technique. This meta-analysis reviewed the results of 41 studies published between 1998 and 2017 in Korea. The overall weighted mean effect size value was .753 with .064 standard error which was calculated by random effects model. PBL strategies have been found to be more effective in mathematics course (d=.922), art course (d=.916), practical art course (d=.827), E-PBL (d=.791) and middle school level (d=.972). As PBL exhibit a substantial effect on students' problem solving skill, it is recommended that teachers should learn how to implement these strategies in their lesson. PBL is expected to contribute to the improvement of teaching methods as the learning environment changes during the 4th Industrial Revolution.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.23-36
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• 2016

We consider a model that minimizes the total cost incurred by assigning available weapons to existing targets in order to reduce enemy threats, which is called the weapon target assignment problem (WTAP). This study addresses the stochastic versions of WTAP, in which data, such as the probability of destroying a target, are given randomly (i.e., data are identified with certain probability distributions). For each type of random data or parameter, we provide a stochastic optimization model on the basis of the expected value or scenario enumeration. In particular, when the probabilities of destroying targets depending on weapons are stochastic, we present a stochastic programming formulation with a simple recourse. We show that the stochastic model can be transformed into a deterministic equivalent mixed integer programming model under a certain discrete probability distribution of randomness. We solve the stochastic model to obtain an optimal solution via the mixed integer programming model and compare this solution with that of the deterministic model.

• Journal of Korean Academy of Nursing
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• v.40 no.2
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• pp.161-171
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• 2010

Purpose: The purpose of the study was to identify the prevalence, risk factors and clinical meanings of geriatric foot problems and to suggest implications for the future. Methods: One hundred eighty nine elderly aged 60 and over from institution as well as community were investigated for their foot conditions by means of a questionnaire including general characteristics, self care capacity, risk factors, foot problem checklist, X-ray, podoscopy and foot scan. Descriptive statistics and $\chi^2$-test was performed as appropriate utilizing SPSS version 14. Less than .05 of p-value was adopted as statistical significance level. Results: All subjects had at least one kind of foot problem and the most prevalent ones were nail problems, foot deformities in order. Prevalence of foot pain and edema was relatively low. Conclusion: Foot problem in elderly is prevalent and geriatric foot is expected to emerge as one of the most important problems in the geriatric field. Therefore strategies to deal with geriatric foot should be developed and practiced for better quality of life in later life.

• The Journal of Information Technology
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• v.4 no.1
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• pp.71-79
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• 2001

This paper presents an adaptive back propagation algorithm that update the learning parameter by the generated error, adaptively and configuration of the range for the initial connecting weight according to the different maximum target value from minimum target value. This algorithm is expected to escaping from the local minimum and make the best environment for the convergence. On the simulation tested this algorithm on three learning pattern. The first was 3-parity problem learning, the second was $7{\times}5$ dot alphabetic font learning and the third was handwritten primitive strokes learning. In three examples, the probability of becoming trapped in local minimum was reduce. Furthermore, in the alphabetic font and handwritten primitive strokes learning, the neural network enhanced to loaming efficient about 27%~57.2% for the standard back propagation(SBP).

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.128-137
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• 2006

Recently the role and the importance of design value engineering is expected to be high, so research is needed for its effective accomplishment. But in domestic arena, the introduction of the history of design value engineering is too short and insufficient in act of research. Therefore in this research we have suggest the standard for the effective accomplishment of design value engineering work. The way is the abstraction many causes. firstly, we analyzed the team project case of value engineering professional instruction. second, we analyzed the cause of problem produced in accomplishment process of design value engineering work through research for the professional field. So from the base of the analyzed content, we have suggest main control factor for the effectiveness of design value engineering work and the following scheme and process of work efficiency optimization.