• Journal of Labour Economics
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• v.43 no.1
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• pp.59-91
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• 2020

The recent reform of child care policy is to give priority to double-income households in the use of childcare facilities. This study analyzed the effect of the use of childcare facilities on the employment of married women under the on-going reform. Using the data from the 19th and 21st wave of the Korean Labor and Income Study, the marginal treatment effect (MTE) analysis method was used to eliminate the selection bias in which the sub-population targeted for policy is determined according to the priority when childcare demand exceeds supply. The study finds that the employment effect of married women who use childcare facilities does not differ statistically from the employment effect of married women who do not use childcare facilities.

• The Journal of Korean Physical Therapy
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• v.5 no.1
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• pp.109-114
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• 1993

The originator of the proprioceptive neuromuscular facilitation method was Dr. Herman Kabat, a man who received the bachelor of science degree from New York University in 1932. In 1936 he moved to the University of Minnesota where he served as instructor in physiology and also studies medicine. He received his medical doctorate in 1942. When Dr. Karbat meet Sister Kenny suggested that certain change. She does not receptive his ideas. So that he decided to pursure the treatment of patients. Upon the establishment of the Karbat- kaiser Institute to be opened in 1946. Margaret Knott, the first physical therapist to be employed by him and to become his head physical therapist. In 1948 Vallejo center was opened. Dr. Kabat developed the PNF method combined motions to ascertain the effectiveness of maximal resistance and stretch in facilitating the response of a weak distal muscle. He identified mass movement patterns that were spiral and diagonal in character in 1965. Margaret Knott presented lecture at tile APTA Annual Conference in Las Vegas. The title was In the groove. On December 18, 1978 she passed away at her home in Vallejo. Marie-Louise Mangold is director of the Kaiser Foundation Rehabilitation Center now. She is the Vice President of International Proprioceptive Neuromuscular facilitation Association. About 20 physical therapist working teaching and study at KFRC in Vallejo. PNF neuromuscular mechanism becomes integrated and efficient without awareness of individual muscle action, reflex and a multitude of other neurophysiological reactions. The principles of PNF are visual consideration, verbal consideration, and proprioceptive input consideration with tactile stimulation, joint receptors, appropriate facilitation, stretch reflex normal timing, irradiation, pattern of movement.

• Transactions on Electrical and Electronic Materials
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• v.11 no.4
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• pp.155-165
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• 2010

As a promising candidate to replace the conventional floating gate flash memories, polysilicon-oxide-nitride-oxidesilicon (SONOS)-type nonvolatile semiconductor memories have been investigated widely in the past several years. SONOS-type memories have some advantages over the conventional floating gate flash memories, such as lower operating voltage, excellent endurance and compatibility with standard complementary metal-oxide-semiconductor (CMOS) technology. However, their operating speed and date retention characteristics are still the bottlenecks to limit the applications of SONOS-type memories. Recently, various approaches have been used to make a trade-off between the operating speed and the date retention characteristics. Application of high-k dielectrics to SONOS-type memories is a predominant route. This article provides the state-of-the-art research progress of high-k dielectrics applicable to SONOS-type nonvolatile semiconductor memories. It begins with a short description of working mechanism of SONOS-type memories, and then deals with the materials' requirements of high-k dielectrics used for SONOS-type memories. In the following section, the microstructures of high-k dielectrics used as tunneling layers, charge trapping layers and blocking layers in SONOS-type memories, and their impacts on the memory behaviors are critically reviewed. The improvement of the memory characteristics by using multilayered structures, including multilayered tunneling layer or multilayered charge trapping layer are also discussed. Finally, this review is concluded with our perspectives towards the future researches on the high-k dielectrics applicable to SONOS-type nonvolatile semiconductor memories.

• Journal of Korean Society of Archives and Records Management
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• v.18 no.1
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• pp.79-99
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• 2018

The system for reporting record production has been operated to collect and transfer the public records adequately since the enactment of the Public Records Management Act in 1999. The Act, which was revised in 2007, regulates automated reporting methods in which the production reporting files are generated in the records creation systems and transferred to the records management systems. However, only one type of record is being notified electronically among seven types, which should be notified under the Act. The remaining six types of records are laboriously reported using complicated templates. Furthermore, the current working electronic notification mechanism is also causing various errors mainly because of inadequate specifications. This study analyzes the causes of failure of the electronic notification through the electronic records systems and suggests some policies for its improvement.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.65-72
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• 2016

In this study, a fully active transfemoral prothesis with a knee joint is designed considering stair walking conditions. Since the torque at the knee joint required for stair walking condition is relative high compared with the one in normal walking condition, the proposed design has high torque generating mechanism. Moreover, the transfemoral prothesis is designed in compact size to reduce its weight, which is related to comfortable fit and fatigue of patients. Flat type BLDC motor is used for simple and compact structure and various components are used to generate required torque with target working angle and speed. The weight reduction of structure is carried out using optimization method after the initial design process is complete. The optimization is conducted under the load conditions of stair walking. The optimized design is validated via finite element analysis and experiments. As a result, the weight is reduced using topology and shape optimization but maintaining the safety of structure. Also the space efficiency is improved due to its compact size.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.719-725
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• 1997

This paper presents results of experimental studies on the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. As a result, the crust, which is a solidified layer, may form at the top of the molten metal pool. Heat transfer is accomplished by a conjugate mechanism, which consists of the natural convection of the molten metal pool, the conduction in the crust layer and the convective boiling heat transfer in the coolant. This work examines the crust formation and the heat transfer rate on the molten metal pool with boiling coolant. The simulant molten pool material is tin (Sn) with the melting temperature of 232$^{\circ}C$. Demineralized water is used as the working coolant. The crust layer thickness was ostensibly varied by the heated bottom surface temperature of the test section, but not much affected by the coolant injection rate. The correlation beかeon the Nusselt number and the Rayleigh number in the molten metal Pool region of this study is compared against the crust formation experiment without coolant boiling and the literature correlations. The present experimental results are higher than those from the experiment without coolant boiling, but show general agreement with the Eckert correlation, with some deviations in the high and low ends of the Rayleigh number. This discrepancy is currently attributed to concurrent rapid boiling of the coolant on top of the metal layer.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.5
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• pp.1043-1058
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• 1990

The Strain rate effect in electro-magnetic forming, which is one of the high velocity forming methods, is studied by the finite element method in this paper. The forming process is simplified by neglecting the coupling between magnetic field and work-piece deformation, and the impulsive magnetic pressure is regarded as inner pressure load. A rate-dependent elasto-plastic material model, of which tangential modulus depends of effective strain rate, is proposed. The model is shown to well describe the transient increase of yield stresses, the decreases of the final displacement and yield stress, the decrease of the difference in the distribution of deformation along the axial direction, and the change of deformation mechanism due to strain rate effect. As a result, displacement, final deformed shape, radial velocity, deformation energy, and the changes of effective stress, effective strain and effective strain rate through plastic working are given. Based on the results, the effectiveness of this model and the strain rate effect of the deformation process of the work-piece are discussed.

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.103-113
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• 2012

The ButterStar Observatory at the Dongducheon High School has been working for photographic observations of the Sun since October 16, 2002. In this study, we observed the Sun at the ButterStar observatory for 3,364 days from October 16, 2002 to December 31, 2011, and analyzed the photographic sunspot data obtained in 1,965 days. The correction factor $K_b$ for the entire observing period is 0.9519, which is calculated using the linear least square method to the relationship between the daily sunspot number, $R_B$, and the daily international relative sunspot number, $R_i$. The yearly correction factor calculated for each year varies slightly from year to year and shows a trend to change along the solar cycle. The correction factor is larger during the solar maxima and smaller during the solar minima in general. This implies that the discrepancy between a relative sunspot number, R, and the daily international relative sunspot number, $R_i$, can be reduced by using a yearly correction factor. From 2002 to 2008 in solar cycle 23, 35.4% and 64.6% of sunspot groups and 35.1% and 64.9% of isolated sunspots in average occurred in the northern hemisphere and in the southern hemisphere, respectively, and from 2008 to 2011 in solar cycle 24, 61.3% and 38.7% of sunspot groups and 65.0% and 35.0% of isolated sunspots were observed, respectively. This result shows that the occurrence frequency for each type of sunspot group changes along the solar cycle development, which can be interpreted as the emerging and decaying process of sunspot groups is different depending on the phase of solar cycle. Therefore, it is considered that a following study would contribute to the efforts to understand the dependence of the dynamo mechanism on the phase of solar cycle.

• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.169-178
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• 2015

Purpose: This study was to investigate usage satisfaction of multi type handpiece with equipped air-jet function Methods: The subjects of this study through the survey was conducted for fifty-nine dental technicians in Daegu and Gyeongsangbukdo from the May 7 to 19, after the June 23 to July 4 2014. The survey was about the function and quality through user testing environment by cutting zirconia specimens using appliance for zirconia. The collected date was analyzed by the statistical program SPSS Win Ver 19.0 for the satisfaction of handpiece and control system. To test for significance on each item, p<0.05 had been decided a standard. General characteristics and relationship between the handpiece and control system was performed correlation analysis. Results: The results of this study is as follows. 35 dental technicians had 1~2 years career in zirconia part as the highest 59.3%, 95% of subjects expected that the prospects for the zirconia material have bright prospects. The satisfaction of multi type handpiece and control system design and function showed a significant difference. Subjects satisfied with the design and function of the multi type showed negative correlation with those of Standard. The satisfaction of multi type handpiece showed 3.37 points of air jet, 3.05 points of noise level, 2.69 points of water flow rate, and 1.98 points of cruise function. Sample differences in all parameters showed a statistically higher difference. Conclusion: High-speed cutting mechanism of multi-type is recommended working with zirconia materials and the multi-type unit combined handpiece motor, air-turbine and air-gun will be expected the increase of user due to the high satisfaction of air jet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.452-455
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• 2017

As the number of high - rise buildings has increased recently, this research society has become interested in the method of cleaning the external wall required. When cleaning these areas, an accident occurs every year when a person uses dangerous manual labor using a gondola. The main goal of this work is to enable people to manipulate the robot with simple operation without dangerous manual operation when working in a vertical structure. As the altitude increases, the concept of the mechanism attaching to the vertical structure while enduring the external resistance in the increase of the wind strength is applied, and the additional attachment device is attached to the end of the leg based on the existing four- According to the control, the development result of the robot having the function of detachable to the glass is presented.