• Safety and Health at Work
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• v.8 no.2
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• pp.117-129
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• 2017

Chronic disease rates have become more prevalent in the modern American workforce, which has negative implications for workplace productivity and healthcare costs. Offering workplace health interventions is recognized as an effective strategy to reduce chronic disease progression, absenteeism, and healthcare costs as well as improve population health. This review documents intervention and evaluation strategies used for health promotion programs delivered in workplaces. Using predetermined search terms in five online databases, we identified 1,131 published items from 1995 to 2014. Of these items, 27 peer-reviewed articles met the inclusion criteria; reporting data from completed United States-based workplace interventions that recruited at-risk employees based on their disease or disease-related risk factors. A content rubric was developed and used to catalogue these 27 published field studies. Selected workplace interventions targeted obesity (n = 13), cardiovascular diseases (n = 8), and diabetes (n = 6). Intervention strategies included instructional education/counseling (n = 20), workplace environmental change (n = 6), physical activity (n = 10), use of technology (n = 10), and incentives (n = 13). Self-reported data (n = 21), anthropometric measurements (n = 17), and laboratory tests (n = 14) were used most often in studies with outcome evaluation. This is the first literature review to focus on interventions for employees with elevated risk for chronic diseases. The review has the potential to inform future workplace health interventions by presenting strategies related to implementation and evaluation strategies in workplace settings. These strategies can help determine optimal worksite health programs based on the unique characteristics of work settings and the health risk factors of their employee populations.

• Journal of Hospice and Palliative Care
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• v.24 no.4
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• pp.214-225
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• 2021

Purpose: This study reviewed screening and assessment tools that are used to measure delirium in patients with cancer in hospice and palliative care settings and examined their psychometric properties. Methods: Four databases were searched for studies using related search terms (delirium, tools, palliative care, cancer, and others). The inclusion criteria were a) studies that included screening/assessment tools for measuring delirium in cancer patients receiving hospice/palliative care, and b) studies published in English or Korean. The exclusion criteria were a) studies that were conducted in an intensive care setting, and b) case studies, qualitative studies, systematic reviews, or meta-analyses. Results: Out of the 81 studies identified, only 10 examined the psychometric properties of tools for measuring delirium, and 8 tools were ultimately identified. The psychometric properties of the Memorial Delirium Assessment Scale (MDAS) were the most frequently examined (n=5), and the MDAS showed good reliability, concurrent validity, and diagnostic accuracy. The Delirium Rating Scale had good reliability and diagnostic accuracy. The Delirium Rating Scale-Revised 98 also showed good reliability and structural validity, but its diagnostic performance was not examined in hospice/palliative care settings. The Nursing Delirium Screening Scale showed relatively low diagnostic accuracy. Conclusion: The MDAS showed evidence of being a valid assessment tool for assessing delirium in patients with cancer in palliative care. Few studies examined the diagnostic performance of delirium tools. Therefore, further studies are needed to examine the diagnostic performance of screening/assessment tools for the optimal detection of delirium in patients with cancer in hospice/palliative care.

• Journal of Technologic Dentistry
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• v.46 no.1
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• pp.1-7
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• 2024

Purpose: The goal of this study was to determine the clinical acceptability of various cement space settings for the marginal and internal fit of a zirconia core manufactured using additive manufacturing. Methods: The maxillary right incisor served as the master model. After scanning the maxillary right incisor with a dental 3D (three-dimensional) scanner, the stereo lithography file was created using different cement space settings of 40, 120, and 200 ㎛ using computer-aided design software (Dental System 2018; 3Shape). The marginal and internal fit of the 3 groups were determined using the silicon replica technique. Measurement points were divided into the following three categories: margin, axial wall, and incisal. To ensure more accurate measurements, these three measurement points were divided into 8 points. The Shapiro-Wilk, one-way ANOVA, and Tukey's honestly significant difference test (for all tests α=0.05) were the statistical analyses that were included in the study. Results: The CS (cement space)-200 group had better marginal and internal fit than the CS-40 and CS-120 groups, and there were statistically significant differences at the marginal and incisal points, except for the axial wall points. CS-200 group, both marginal and internal fit were within 120 ㎛, which is the clinically acceptable value. Conclusion: This study suggests that a 200 ㎛ cement space setting is ideal for optimal marginal and internal fit of 3D-printed ceramic crowns.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.9
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• pp.472-481
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• 2017

Radiant floor heating systems have been used as common heating supply systems in most residential buildings in Korea. Since the system uses a floor as thermal storage, proper control strategy should be adopted to avoid over-or under-heating problems. So far, studies related to control of the floor heating system have been conducted based on computer simulations. The active layer in TRNSYS is known for its usability as a floor heating system model and is integrated with the TRNSYS building model (Type 56). However, floor heating system simulations with the active layer are operated only if pre-defined minimum mass flow rate is ensured. This study proposes a simple RC (Resistance-Capacitance) model for radiant floor heating systems. Model parameters such as Rs and Cs are defined by optimization. The active layer, in this study, is used as the target system to search for optimal values. A TRNOPT optimization tool was used to conduct optimization under given simulation conditions. The RC model with optimal parameters are tested in other mass flow rates that were not used during optimization. Results reveal the RC model describes the active layer with successfully optimized model parameters. The RC model has fewer model limitations, and is expected to be used for various target systems, e.g. experimental data of a real radiant heating system.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.92-97
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• 2021

The importance of processes in cryogenic environments is increasing in a way to address problems such as critical dimension (CD) narrow and bottlenecks in micro-processing. Accordingly, in this paper, we proceed with the design and analysis of Electrostatic Chuck(ESC) and Coolant in cryogenic environments, and present optimal model conditions to provide the temperature distribution analysis of ESC in these environments and the appropriate optimal design. The wafer temperature uniformity was selected as the reference model that the operating conditions of the refrigerant of the liquid nitrogen in the doubled aluminum path were excellent. Design of simulation (DOS) was carried out based on the wheel settings within the selected reference model and the classification of three mass flow and diameter case, respectively. The comparison between factors with p-value less than 0.05 indicates that the optimal design point is when five turns of coolant have a flow rate of 0.3 kg/s and a diameter of 12 mm. ANOVA determines the interactions between the above factor, indicating that mass flow is the most significant among the parameters of interests. In variable selection procedure, Case 2 was also determined to be superior through the two-Sample T-Test of the mean and variance values by dividing five coolant wheels into two (Case 1 : 2+3, Case 2: 3+2). Finally, heat transfer analysis processes such as final difference method (FDM) and heat transfer were also performed to demonstrate the feasibility and adequacy of the analysis process.

• Animal Bioscience
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• v.36 no.11
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• pp.1757-1768
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• 2023

Objective: The number of bovine mammary epithelial cells (BMECs) is closely associated with the quantity of milk production in dairy cows; however, the optimal levels and the combined effects of hormones and essential amino acids (EAAs) on cell proliferation are not completely understood. Thus, the purpose of this study was to determine the optimal combination of individual hormones and EAAs for cell proliferation and related signaling pathways in BMECs. Methods: Immortalized BMECs (MAC-T) were treated with six hormones (insulin, cortisol, progesterone, estrone, 17β-estradiol, and epidermal growth factor) and ten EAAs (arginine, histidine, leucine, isoleucine, threonine, tryptophan, lysine, methionine, phenylalanine, and valine) for 24 h. Results: Cells were cultured in a medium containing 10% fetal bovine serum (FBS) as FBS supplemented at a concentration of 10% to 50% showed a comparable increase in cell proliferation rate. The optimized combination of four hormones (insulin, cortisol, progesterone, and 17β-estradiol) and 20% of a mixture of ten EAAs led to the highest cell proliferation rate, which led to a significant increase in cell cycle progression at the S and G2/M phases, in the protein levels of proliferating cell nuclear antigen and cyclin B1, cell nucleus staining, and in cell numbers. Conclusion: The optimal combination of hormones and EAAs increased BMEC proliferation by enhancing cell cycle progression in the S and G/2M phases. Our findings indicate that optimizing hormone and amino acid levels has the potential to enhance milk production, both in cell culture settings by promoting increased cell numbers, and in dairy cows by regulating feed intake.

• Journal of Music and Human Behavior
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• v.13 no.1
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• pp.19-40
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• 2016

This study provides numerical data on the status of music therapy practices in 54 hospice and palliative care settings in Korea. Two different questionnaires for music therapists and coordinators were sent to 54 coordinators via email, and 47 (87%) hospitals and centers replied by email or post. The survey period was October 30 through December 5, 2014. Music therapists were asked to respond to 65 questionnaire items regarding working conditions, environment, session process, and personal competence. Coordinators were asked to complete 28 questionnaire items regarding the status of music therapy in their perspective setting. Twenty-two (46.8%) hospitals and centers were running music therapy programs with 28 music therapists, and 19 (67.9%) of these music therapists majored in music therapy. There was a significant difference between music therapists (M= 3.43, SD = 0.96) and coordinators (M= 2.73, SD = 0.77) regarding conditions and environment of music therapy sessions (p < .05). The circumstances and conditions for music therapy are inad quate for optimal implementation of music therapy practice. However, the perceived benefits of music therapy by coordinators suggest that music therapists do play an important role in hospice and palliative care. This research provides the first quantitative baseline data of music therapy status in hospice and palliative care settings in Korea.

• Journal of The Korean Association For Science Education
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• v.4 no.1
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• pp.15-25
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• 1984

The purpose of this study is to develop a practical and ideal model of science laboratory enrolled 48-60 students by studying optimal facilities such as laboratory tables and chairs proper to elementary school settings. The science laboratory model was figured out in terms of the following six procedures; (1) Current status as well as problems of science laboratory and its facilities was identified by means of the questionnaires conducted to 201 elementary schools, using stratified cluster sampling tehnique, under the consideration of the school size and the regional characteristics across the country. (2) Collected were the anthropometric data with respect to sitting height, popliteal height, buttock popliteal length, elbow rest height, and back width from the 747 students, 4th-6th grade, in Seoul area. (3) It was measured the work apace necessary for individual student to perform his experiment. (4) Using the data of the process (2), we determined the optimal sizes of laboratory tables and chairs fitted for Korean elementary school students. (5) The optimal area of science laboratory for 48-60 students is determined in terms of the data obtained in (3) for individual work space in addition to the appropriate table size figured out by (4). (6) A practical and ideal model for a science laboratory in elementary school was designed according to the above procedures. For the optimal model of science laboratory, the results of this study can be summarized as follows: The sizes of chair and table are categorized into three groups such as small, medium, and large depending on students' physical outfit. The small size base on the 12.5th percentile point of students' sitting height is used for students of the 0-25th percentile ranks. The medium size base on the 50th percentile point of students' sitting height is used for students of the 26-75th percentile ranks. The large size base on the 87.5th percentile point of students' sitting height is used for students of the 76-100th percentile ranks. (1) Sizes of chairs: The small size is 28cm in width and 33cm in height. The medium size is 31cm in width and 36cm in height. The large size is 35cm in width and 38cm in height. (2) Sizes of laboratory tables: The small size is 120cm in length, 86cm in width, and 60cm in height. The large size is 120cm in length, 86cm in width, and 60cm in height. The large size is 120cm in length, 86cm in width, and 65cm in height. (3) Size of science laboratory: The optimal science laboratory for 48-60 elementary school students, which can install the 12 laboratory tables, is 12m in length and 10m in width.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.190-193
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• 2004

Optimal Power Flow (OPF) is becoming more and more important in the deregulation environment of power pool and there is an urgent need of faster solution technique for on-line application. So this paper presents parallel genetic algorithm-tap search for the solution of the OPF. The control variables modeled unit active power outputs, generator-bus voltage magnitudes and transformer-tap settings. A number of functional operating constraints, such as branch flow limits, load bus boltage magnitude limits and generator reactive capabilities are included as penalties in the fitness function. In parallel GA-TS, GA operators are executed for each process. If best fitness of the GA is not changed for several generations, TS operators are executed for the upper three populations to enhance the local searching capabilities. With migration operation, best string of each node is transferred to the neighboring node after predetermined iterations are executed. For parallel computing, we developed a PC-cluster system consisting of 8 PCs. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through ethernet switch based fast ethernet. To show the usefulness of the proposed method, developed algorithm has been tested and compared on an IEEE 30-bus system in the reference paper. From the simulation results, we can find that the proposed algorithm is efficient for the OPF.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.754-758
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• 2005

Optimization of process variables such as arc current, welding voltage and welding speed in terms of the weld characteristics desired is the key step in achieving high quality and improving performance characteristics without increasing the cost. Consequently, incorrect settings of those process variables give rise to deviations in the welding characteristics from the desired bead geometry. Therefore, trainee welders are referred to the tabulated information relating different metal types and thickness as to recommend the desired values of process variables. Basically, the bead geometry plays an important role in determining the mechanical properties of the weld. So that it is very important to select the process variables for obtaining optimal bead geometry. However, it is difficult for the traditional identification methods to provide an accurate model because the optimized welding process is non-linear and time-dependent. In this paper, the possibilities of the Infra-red sensor in sensing and control of the bead geometry in the automated welding process are presented. Infra-red sensor is a well-known method to deal with the problems with a high degree of fuzziness so that the sensor is employed to build the relationship between process variables and the quality characteristic the proposed above respectively. Based on several neural networks, the mathematical models are derived from extensive experiments with different welding parameters and complex geometrical features. The developed system enables to select the optimal welding parameters and control the desired weld dimensions during arc welding process.