• Safety and Health at Work
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• v.8 no.1
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• pp.36-41
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• 2017

Background: Police work is generally sedentary although there may be situations that require physical endurance and strength, such as foot chases and arresting suspects. Factors such as excessive body fat can impede an officer's physical ability to deal with such occurrences. Our objective was to examine associations between officers' body fat percentage (BF%) and performance on a standardized fitness protocol. Methods: Data were obtained from fitness screening among 1,826 male and 115 female officers in a large US police agency. The screening consisted of a 2.4-km run, push-ups, sit-ups, and sit-and-reach test. Sex-specific body fat percentages were estimated from skinfold thickness measured using calipers. Linear regression models were used to examine unadjusted and adjusted mean scores of fitness tests across BF% tertiles. Results: The prevalence of overall fitness was 4.3 times greater in male officers and 3.6 times greater in female officers having the lowest BF% tertile compared with the highest tertile (30.3% vs 7.1% and 46.0% vs 12.8%, respectively). BF% was linearly and positively associated with the time of 2.4-km run (p < 0.001), and linearly and inversely associated with the number of push-ups (p < 0.001), sit-ups (p < 0.001), and the distance of sit-and-reach (p < 0.001) in men. Similar associations were observed in women with the exception of sit-and-reach (p = 0.122). Associations were independent of age, race/ethnicity, rank, and duty station. Conclusion: Overall, BF% was inversely associated with fitness levels in male and female officers. Future longitudinal studies should be initiated to explore the potentially causal relationship between BF% and fitness in law enforcement officers.

• Journal of Service Research and Studies
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• v.7 no.2
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• pp.1-16
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• 2017

The service that has been recognized as both a non-productive activity and auxiliary activity of manufacturing have become the driving force of the customers' demand with the 'service' itself. The service base is expanding and evolving rapidly. It is important to look at changes in service concepts to understand service systems. Because the service system itself has a cyclic nature based on the concept of service, it can help in the study and the "how" of service by looking at changing the system according to the evolution of the service concept. The ability to organize and utilize relationships is considered to be an important factor for managers in the service economy era. However, the attention of corporate is focused on their internal capabilities and they are familiar with external resources (knowledge and competence of customers). In this case study for each type of service, we analyzed the activities of interacting service providers-consumers in service relationship, and constructed a new service system model emphasizing intangible value and long-term outcome. This study is worth re-examining the role of customers in today's service economy era and actively utilizing a new service model for business performance.

• Journal of Gifted/Talented Education
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• v.25 no.6
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• pp.771-797
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• 2015

The purpose of this study was to assess musically gifted students'needs in order to develop the gifted curriculum in music. The survey was carried out with 103 musically gifted students who are being educated in institutes for the gifted. The survey asked the needs about components of the gifted curriculum in music: the educational objectives, contents, teaching strategies, evaluation as well as educational environment influencing on the curriculum. As for the objectives, the result showed the highest needs was the ability to communicate with audience by expressing one's feeling. For the high school students, a large number items had significant differences between the necessary level and the current level. As for the contents, the highest needs were the class piano, second instrument, and the experience of the musical field. High school students needed the second instrument more than middle school students did. As for the teaching strategies, the highest needs were the autonomous choice by learners, the instruction pursuing learners' interests, and the field work. As for the evaluation, the highest needs were the peer evaluation and the evaluation on the collaborative performance or team work. As for the educational environment, the gifted in music strongly needed spaces to practice instruments. Additionally, high school students needed a space to perform like a concert hall. Thus the gifted curriculum in music must be thoroughly developed based on the result above.

• Journal of Life Science
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• v.17 no.10
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• pp.1400-1405
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• 2007

The effect of supplementation with docosahexaenoic acid into n-3 fatty acid deficient diet on improvement of loaming related brain function was investigated. On the second day after conception, Sprague Dawley strain dams were subjected to a diet containing either n-3 fatty acid deficient (Def) or n-3 fatty acid deficient + docosahexaenoic acid (Def+DHA). After weaning, male pups were fed on the same diet of their respective dams until adulthood. Motor activity and Morris water maze tests were measured at 10 weeks old. In motor activity test, there were no statistically significant differences in moving time and moving distance between the Def and Def+DHA diet groups. The n-3 fatty acid deficient with DHA (Def+DHA) group exhibited a shorter escape latency, swimming time and swimming distance (P<0.05) compared to the n-3 fatty acid deficient group (Def) but there was no difference in resting time and swimming speed between the experimental diet groups. In memory retention trial, the number of crossing of the platform position (region A) was significantly greater than those of other regions for the Def+DHA group. However, the Def group swam randomly without preference for the provisions platform location, indicating poorer memory retention. From those results, supplementation with DHA into the n-3 fatty acid deficient diet improved the spatial loaming ability in rats as assessed by Morris water maze test.

• Communications of Mathematical Education
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• v.23 no.1
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• pp.109-128
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• 2009

This study aimed to investigate students' learning process by examining their perception process of problem structure and mathematization, and further to suggest an effective teaching and learning of mathematics to improve students' problem-solving ability. Using the qualitative research method, the researcher observed the collaborative learning of two middle school students by providing problem-posing activities of five lessons and interviewed the students during their performance. The results indicated the student with a high achievement tended to make a similar problem and a new problem where a problem structure should be found first, had a flexible approach in changing its variability of the problem because he had advanced algebraic thinking of quantitative reasoning and reversibility in dealing with making a formula, which related to developing creativity. In conclusion, it was observed that the process of problem posing required accurate understanding of problem structures, providing students an opportunity to understand elements and principles of the problem to find the relation of the problem. Teachers may use a strategy of simplifying external structure of the problem and analyzing algebraical thinking necessary to internal structure according to students' level so that students are able to recognize the problem.

• Membrane Journal
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• v.15 no.3
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• pp.224-232
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• 2005

The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.425-431
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• 2015

Since the construction of Kori 1 was completed in 1978, the construction projects for nuclear power plant are increasingly expanded into domestic and foreign sites. However, some of construction sites of nuclear power plant have the problems of process delay and cost loss due to lack of ability of risk management. The construction of reactor containment building in nuclear power plant is especially dotted with many risk factors because it needs professional skills and large-scale resources due to long duration compared with different construction phase. Therefore, it needs the study that analyzes risk factors expected in construction of reactor containment building and suggests way of stable performance of projects. So, this study assesses risk factors of construction of reactor containment building. For the objectives, this study uses survey for group of minority specialists of 36 experts. The risks of 24 factors is classified by criterions of process, cost, safety, and quality and the results of assessment is analyzed by analytic hierarchy process. As the results, the importance and priority of risk factors classified by each criterion were calculated and the applicability of analytic hierarchy process was identified to analyze risk factors of nuclear power plant construction. These will be baseline data for risk management in construction phase of reactor containment building.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.68-76
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• 2014

The accurate estimation of construction cost is important to a successful development in construction projects. In previous studies, the construction cost are estimated by statistical methods. Among the statistical methods, support vector regression (SVR) has attracted a lot of attentions because of the generalization ability in the field of cost estimation. However, despite the simplicity of the parameter to be adjusted, it is not easy to find optimal parameters. Therefore, to build an effective SVR model, SVR's parameters must be set properly without additional data handling loads. So this study proposes a novel approach, known as genetic algorithm (GA), which searches SVR's optimal parameters, then adopt the parameters to the SVR model for estimating cost in the early stage of apartment housing projects. The aim of this study is to propose a GA-SVR model and examine the feasibility in cost estimation by comparing with multiple regression analysis (MRA). The experimental results demonstrate the estimating performance based on the percentage of estimations within 25% and find it can effectively do the accurate estimation without through the trial and error process.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.249-257
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• 2007

The periodic square wave (PSW) model was successfully applied to the optimal design of a batch-storage network. The network structure can cover any type of batch production, distribution and inventory system, including recycle streams. Here we extend the coverage of the PSW model to multitasking semi-continuous processes as well as pure continuous and batch processes. In previous solutions obtained using the PSW model, the feedstock composition and product yield were treated as known constants. This constraint is relaxed in the present work, which treats the feedstock composition and product yield as free variables to be optimized. This modification makes it possible to deal with the pooling problem commonly encountered in oil refinery processes. Despite the greater complexity that arises when the feedstock composition and product yield are free variables, the PSW model still gives analytic lot sizing equations. The ability of the proposed method to determine the optimal plant design is demonstrated through the example of a high density polyethylene (HDPE) plant. Based on the analytical optimality results, we propose a practical process optimality measure that can be used for any kind of process. This measure facilitates direct comparison of the performance of multiple processes, and hence is a useful tool for diagnosing the status of process systems. The result that the cost of a process is proportional to the square root of average flow rate is similar to the well-known six-tenths factor rule in plant design.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.819-826
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• 2018

The generalized Hamming weight is one of the important parameters of the linear code. It determines the performance of the code when the linear codes are applied to a cryptographic system. In addition, when the block code is decoded by soft decision using the lattice diagram, it becomes a measure for evaluating the state complexity required for the implementation. In particular, a bit-parallel multiplier on finite fields based on trinomials have been studied. Cellular automata(CA) has superior randomness over LFSR due to its ability to update its state simultaneously by local interaction. In this paper, we deal with the efficient synthesis of the pseudo random number generator, which is one of the important factors in the design of effective cryptosystem. We analyze the property of the characteristic polynomial of the simple 90/150 transition rule block, and propose a synthesis algorithm of the reversible 90/150 CA corresponding to the trinomials $x^2^n+x^{2^n-1}+1$($n{\geq}2$) and the 90/150 reversible CA(RCA) corresponding to the maximum weight polynomial with $2^n$ degree by using this rule block.