• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.215-228
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• 2015

A creative innovation and an innovative problem-solving of industrial companies can be achieved by overcoming the challenges of technical and physical contradictions. The approaches to address conflicting and paradoxical problems, such as technical and physical contradictions have a crucial role in advancing the quality assessment for manufacturer and service provider. The term, technical contradiction, depicts the state that improvement of one ends of IFR (Ideal Final Result) leads to unfavorable condition of the other ends, and results in conflicting problem. Another type of contradictions that's discussed in this study is a physical contradiction which is due to two mutually opposing states of the means of ends, and gives paradoxical situation. By integrating the means-ends chain perspectives, the physical contradiction that is a specifically root-causes, "means", can be initially addressed to resolve the downstream problem of technical contradiction which represents a general and abstract goals, "ends". This research suggests IFR resolution processes to handle both physical contradiction of means and technical contradiction of ends by employing causal relationship with IFR, effects and causes. In summary, the study represents three major processes that resolve such contradictions are demonstrated as follows: 1) Derivation of causal and hierarchical relationship among IFR, ends and means by considering CAED (Cause-And-Effect Diagram) and LT (Logic Tree). 2) Identification of causal relationship between physical contradiction and technical contradiction by using TPCT (TRIZ Physical Contradiction Tree) and TCD (Technical Contradiction Diagram). 3) Application of integrated TRIZ principles by classifying 40 inventive principles into 4 general conditions of the separation principle of mutually opposite states in space, in time, based on conditions, and between the parts and the whole. In order to validate the proof of proposed IFR resolution processes, the analysis of the TRIZ case studies from National Quality Circle Contest in the years, 2011 to 2014 have been proposed. The suggested guidelines that are built based on TRIZ principles can uniquely enhance the process of quality innovation and assessment for quality practitioners.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.273-282
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• 2017

This paper is aimed at proposing a new approach to connecting the measurements of customer satisfaction on healthcare services with the prioritized identification of healthcare service processes to be improved. As customers' requirements for healthcare services have become too diverse and healthcare service systems have been increasingly complex, there has been growing interest in the customer-oriented evaluation of healthcare service quality and the systematic improvement of healthcare service processes. Most of the previous studies on service quality evaluation are based on SERVQUAL model. However, because of the unique characteristics and constraints inherent in healthcare service systems, it has been reported that SERVQUAL would be inadequate to be applied to healthcare service systems. As an alternative, SERVPERF has recently been widely used in the evaluation of healthcare service quality. However, there is a lack of studies on how to use the measurements of healthcare service quality systematically to improve service functions and processes. With this issue in mind, we firstly measured the customer-perceived satisfaction on the healthcare service quality from the six dimensions based on SERVPERF. Then we identified the relationships between the subjective measurements and healthcare service processes through brainstorming and expert interview. By using the relationships, we developed a customer journey map in healthcare services that visually describe the interaction between customers and healthcare service systems. The developed customer journey map would help service designers easily identify a healthcare service process that needs to be improved with priority. It is expected that the design improvement process proposed in this study would be a useful method for enhancing the quality of healthcare services.

• Journal of Industrial Convergence
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• v.19 no.6
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• pp.177-186
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• 2021

This review aims to propose a model that can reinterpret the abnormal and functional connections between cognitive processes and emotional regulations based on the neurocognitive networks for a comprehensive understanding of pathologic processes and treatment approach of depression and anxiety disorder. Through the processes of rebuilding the network model for depression and anxiety disorder, it was confirmed that depression can be said to be 'over-immersion in self-referencing' due to hyper-activation of default mode network (DMN), and anxiety disorders to be 'disconnection with self-referencing' due to hypo-activation of DMN. The attempts to link up between abnormal activation and pathological function of DMN which is thought to be involved in self-referential processing associated with self-consciousness and projection among neurocognitive networks may be another starting point that can afford to be suggestive in integrated interpretation and therapeutic approach to depression and anxiety disorder.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.19-33
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• 2023

Objectives: The purpose of this study is to systematically identify situations where exposure levels are expected to be high by structuring domestic lead measurement data according to exposure processes and activities. Methods: Occupational exposure data on lead was collected from the results of the Evaluation of Reliability of Working Environment Measurement conducted by the government from 2019 to 2020. Lead exposure characteristics were analyzed by PROC (process category) and activity. The Risk Characterization Ratios (RCRs) of five PROCs according to ventilation type and lead content were evaluated using the MEASE (Metal's EASE) model. Results: The exposure data on lead (n=250) was classified into 12 PROCs and 12 activities, with an average concentration of 0.040 mg/m³ and about 14% exceeding the occupational exposure limit of 0.05 mg/m³. Processes with high exposure levels were PROC 7 (industrial spraying), 23 (open processing and transfer operations of molten metal), 24 (mechanical treatment), 25 (welding), and 26 (handling of powder containing lead). The results of evaluating RCR for the five PROCs were greater than 1 or close to 1 even if local exhaust ventilation was used. Conclusions: There is a possibility that the concentration of exposure is high in the casting and tapping of molten metal containing lead, mechanical treatment such as fracturing and abrasion, handling of powder, spraying, battery manufacturing, and waste battery recycling processes. It is necessary to implement chemical management policies for workplaces with such processes.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.191-199
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• 2021

A distillation column, which is a main facility of the chemical process, separates the desired product from a mixture by using the difference of boiling points. The distillation process requires the optimization and the prediction of operation because it consumes much energy. The target process of this study is difficult to operate efficiently because the composition of feed flow is not steady according to the supplier. To deal with this problem, we could develop a data-driven model to predict operating conditions. However, data preprocessing is essential to improve the predictive performance of the model because the raw data contains outlier and noise. In this study, after optimizing the predictive model based long-short term memory (LSTM) and Random forest (RF), we used a low-pass filter and one-class support vector machine for data preprocessing and compared predictive performance according to the method and range of the preprocessing. The performance of the predictive model and the effect of the preprocessing is compared by using R2 and RMSE. In the case of LSTM, R2 increased from 0.791 to 0.977 by 23.5%, and RMSE decreased from 0.132 to 0.029 by 78.0%. In the case of RF, R2 increased from 0.767 to 0.938 by 22.3%, and RMSE decreased from 0.140 to 0.050 by 64.3%.

• Journal of the Korean institute of surface engineering
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• v.56 no.2
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• pp.147-151
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• 2023

Transparent ZnO (100 nm thick) and ZnO/Ti/ZnO (ZTZ) films were prepared with radio frequency (RF) and direct current (DC) magnetron sputtering on the glass substrate at room temperature. During the ZTZ film deposition, the thickness of the Ti interlayer was varied, such as 6, 9, 12, and 15 nm, while the thickness of ZnO films was kept at 50 nm to investigate the effect of the Ti interlayer on the crystallization and opto-electrical performance of the films. From the XRD pattern, it is concluded that the 9 nm thick Ti interlayer showed some characteristic peaks of Ti (200) and (220), and the grain size of the ZnO (002) enlarged from 13.32 to 15.28 nm as Ti interlayer thickness increased. In an opto-electrical performance observation, ZnO single-layer films show a figure of merit of 1.4×10^-11 Ω^-1, while ZTZ films with a 9 nm-thick Ti interlayer show a higher figure of merit of 2.0×10^-5 Ω^-1.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.2
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• pp.90-103
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• 2005

Objective: This study was carried out to assess the status of working environments, to improve the working environments, and to be helpful to prevent occupational disease. Methods: The authors measured the noise level, concentration of dust, heavy metals, organic solvents, and other chemicals at 95 industries (22 working processes) by type of working process in manufacturing industry of parts and accessories for motor vehicles and its engines from January to December 2003. Samples were measured and analyzed by regulations of Korea Ministry of Labor, manuals of National Institute for Occupational Safety and Health (NIOSH) and Occupational Safety and Health Administration (OSHA). Results: Results are as follows. 1. Major processes exceeding mean noise levels provided the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) were shakeout [97.5 dB(A)]. shot-blast [94.2 dB(A)], pressing [92.9 dB(A)], crushing [91.2 dB(A)], and cleaning [90.6 dB(A)]. 2. Mean concentrations of dusts were not exceeded to the TLV. But concentration on some points of processes as like welding (6.50 mg/m3), foundry (5.24 mg/m3) were exceeded. 3. Mean concentrations of heavy metals were not exceeded to the TLV. 4. Mean concentrations of organic solvents and chemicals were not exceeded to the TLV. 5. Improving rate for working environment were significantly higher in industries with health manager than without (p<0.05), and by increasing the year of working environmental measurement (p<0.01). Conclusions: The results suggest that working processes of exceeding to the TLV will be needed rapid improvement of the working environment, and also the others will be needed positive management of the working environment. Health managers must be recommended to employ in the workplace, and further studies for relationship between working environment and health effects for the workers must be carried out.

• Resources Recycling
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• v.23 no.6
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• pp.12-21
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• 2014

Nickel oxide ores are composed of two kinds of minerals; one is saprolite that is processed by smelting to obtain nickel products, and the other is limonite that is used in hydrometallugical processes. It is not efficient economically to process the mixture of limonite and saprolite, so the processes to saparate the ore mixture should be developed. In the present study, the mixture was separated by dry-classification after liberationg using grindability difference between limonite and saprolite. Consequently, it is possible to obtain the limonite with less than 10% of Mg+Si contents, which could be treated by hydrometallurgical processes, when the limonite contain less than 30% of saprolite.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.1
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• pp.56-67
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• 2005

The Processes of a new product design based on ergonomics and customer satisfaction have been studied for years. However, few attempts have been made to systematically include ergonomic design concept to communication service design. Service design can be regarded as a specific type of product design in a way that the processes of product design can also be employed to those of service design. However, a few difficulties may often arise in doing so. First, services have no explicit tangible features, which implies that a customer may not properly appraise contents, quality and functionality of newly designed services with a prototype before launching into market. Second, customer demands on services change more rapidly according to advances in related technology. In the study, we examined earlier studies of product design process and identified that a service design process must alos conform ergonomic methodology, extracting innovative values for creativitybased design and subsequently evaluate its level of customer satisfaction. In this study, we proposed a customer-centered ergonomic design process for communication services. This process includes a hierarchical structure of service requirement identification, customer-centered trend analysis, service scenario development and service evaluation. To prove the practicality of the design process, a case study of communication service design was conducted according to the procedure that follows.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.130-139
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• 2016

The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.