• Korean Journal of Labor Studies
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• v.17 no.1
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• pp.269-295
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• 2011

This paper is about the part-time work and related polices in Netherland, which increased the employment rate for the past 30 years with part-time job creation. Netherland has been successful in making part-time 'good' jobs. There were many factors which contributed to increaing part-time jobs such as market, institution, policies, and industrial relations. There was virtuous cycle between increase in the supply of female labor power and increase in the demand for part-time worker in the labor market. The policies were reinforced which protect part-time workers, introduced the incentive system which was favorable to part-time wokres, guaranteed the right to select working hours to workers. Particularly, the labor market, institutions and policies were created in the midst of the social dialogue. As the polder model has been persisted for almost 30 years, the switch to full-time work or long working-hour model would not be possible. As the poler model is a very specific model based on the Netherland's own social conditions, it is not easy to copy and transplant in other countries.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.501-504
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• 2006

The estimation of the work of heart can be treated as one of the most important parameters for determining the amount of circulating blood needed for harmonious metabolism in the human body. By monitoring the work of heart, one can detect increased work load of heart and start the treatment at the early stage of CHF. Thus it is necessary to estimate the work of heart. The contractility of the left ventricle, the second important parameter for representing the motion of heart, can be estimated through information on the work of heart. In this study, the modified Windkessel model, which has been used for a measure of vascular hemodynamic impedance parameters, was adapted to estimate the work of heart.

• Journal of Labour Economics
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• v.35 no.3
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• pp.83-100
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• 2012

This paper estimates the impacts of introducing the 40 hour work week standard in South Korea on actual working hours, wages and employment. We exploit variation in timing of implementing the 40 hour work week standard across industries and establishment size and estimate the causal effects by a triple difference model. Our results show that the 40 hour work week standard decreased actual working hours by about 43 minutes while it increased hourly wage rate by 6.6%. The probability of new hires decreased by about 2.3% points.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.37-46
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• 2003

This paper is to predict quality deterioration resulting from a caulking process of yoke which is a part of automotive steering system. The caluking is a plastic deformation process involving such as impact of high speed tool, contacts between part and fixtures and strain rate sensitivity of the part material. Elaborate application of finite element method is neccesary to calculate changes of part dimensions because they fall into a level of tolerances. Simple work hardening and strain rate sensitive model is proposed fur the material and applied for the simulation by using Abaqus which is able to cater for elastoplastic rate sensitive material and contacts. Numerical results of test models that represent tensile bar and tensile plate are compared with material data inputs. Dimensional changes for the yoke are calculated from simulations and compared to the mesurements and they show good agreement. The method presented here with the material model proved to be valuable to assess quality deterioration for similar metal forming processes.

• Journal of the Korea Institute of Building Construction
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• v.21 no.2
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• pp.105-112
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• 2021

While the scale of the domestic market for demolition work is steadily increasing, research on cost prediction for demolition work is insufficient. Thus, this study proposes a cost prediction model for demolition work that reflects various attributes influecing the fluctuation of demolition cost. 13 influencing factors and historical cost data were collected based on literature review and experts' advice, and two prediction models were constructed through regression analysis and the prediction accuracy was evaluated. As a result, it showed an average error rate of about 6 to 12%, and it was possible to explore the possibility of use as a reliable prediction model. The results of this study can contribute to estimating appropriate construction cost and improving related standards for domestic demolition works in the future.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.2
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• pp.299-306
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• 1996

This work presents an analytical model, so called modified LMTD method, to predict the thermal performance of finned-tube heat exchanger under frosting conditions. In this model, the total heat transfer coefficient and effective thermal conductivity of the frost layer were defined as a function of frost surface temperature. The surface temperature of the frost layer formed on the heat exchanger was calculated through the analysis of the heat and mass transfer process in the air and frost layer. To examine the validity of this analytical model, the computed results from the present model, such as heat transfer rate, frost mass and thickness of frost, were compared with the ones of the expermental work and LMED method.

• Journal of Biosystems Engineering
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• v.16 no.2
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• pp.159-166
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• 1991

A simulation model was developed for analyzing a crop transport system using SLAMSYSTEM. The developed model could predict total delivered amount and delivery rate of a crop under various conditions of transport and analyze the effects of work factors on the efficiency of the crop transport system. A simulation model was also developed to analyze a rice transport system based on the generalized model of the crop transport system.

• Biomaterials and Biomechanics in Bioengineering
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• v.5 no.1
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• pp.51-64
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• 2020

In this study, the mathematical model that describes blood cell development in the bone marrow (i.e., hematopoiesis) has been studied via the Homotopy Perturbation Method (HPM). The results from the present work compared very well with the numerical solutions from published literature. This work has shown that the HPM is viable for solving delay differential equations born from hematopoiesis problem. The influence of the proliferating cells loss rate, time delay rate and the phase re-entry rate on the population densities of both the proliferating and resting cells were also determined through the underlined procedure.

• ETRI Journal
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• v.43 no.4
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• pp.758-768
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• 2021

In this work, the secrecy of a typical wireless cooperative dual-hop non-orthogonal multiple access (NOMA)-enabled decode-and-forward (DF) relay network is investigated with the impact of collaborative and non-collaborative eavesdropping. The system model consists of a source that broadcasts the multiplexed signal to two NOMA users via a DF relay, and information security against the eavesdropper nodes is provided by a helpful jammer. The performance metric is secrecy rate and ergodic secrecy capacity is approximated analytically. In addition, a differential evolution algorithm-based power allocation scheme is proposed to find the optimal power allocation factors for relay, jammer, and NOMA users by employing different jamming schemes. Furthermore, the secrecy rate analysis is validated at the NOMA users by adopting different jamming schemes such as without jamming (WJ) or conventional relaying, jamming (J), and with control jamming (CJ). Simulation results demonstrate the superiority of CJ over the J and WJ schemes. Finally, the proposed power allocation outperforms the fixed power allocation under all conditions considered in this work.

• Information Systems Review
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• v.14 no.3
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• pp.99-114
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• 2012

In July 2010, The Korean government announced a plan to implement smart work centers to resolve low birth rate, low productivity and social costs of the urban traffic jams. The Plan calls for up to 30 percent of the working population to be working under the smart work system by 2015. This empirical study was conducted to find factors affecting the Smart Work Center use. Based on the IS Success Model, 'operation Infra Quality' and 'User Satisfaction' have positive impact on the Smart Work Center use. 'System Infra Quality' and 'IT Infra Quality' have positive impact on the 'User Satisfaction'. Consequently 'System Infra Quality' and 'IT Infra Quality' have positive impact on the Smart Work Center use indirectly.