• Journal of the Korean Society of Physical Medicine
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• v.7 no.1
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• pp.69-75
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• 2012

Purpose : The study was designed to investigate analysis of kinematics of lower extremity in healthy adults during walking with external loads on trunk. Methods : Fifteen healthy adults were recruited and The subjects provided written and informed consent prior to participation. They walked on a ten-meter walkway at a self-selected pace with loads of 0, 5, 10, and 15kg. They completed three trials in each condition and kinematic changes were measured. A three-dimensional motion analysis system was used to analyze lower extremity kinematic data. The data collected by each way of walking task and analyzed by One-way ANOVA. Results : There were significant differences in hip and knee joint on saggittal plane at initial contact and preswing, and significant differences in ankle joint on transverse plane at preswing. Conclusion : These findings revealed that increased external loads were changed joint angles and influenced postural strategies because of kinematic mechanism and future studies is recommended to find out prevention from damage of activities of daily living.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.796-804
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• 2011

Railway vehicles are capable of indicating several types of instability. This phenomenon, which is called hunting motion, is a self excited lateral oscillation that is caused by the running velocity of the vehicle and wheel frail interactive forces. The interactive forces act to change effectively the damping characteristics of railway vehicle systems. This paper will show the impact of instability on the transfer function behavior using damping characteristics of secondary suspension. The vehicle dynamics are modeled using a 17 degree of freedom considering linear wheel/rail contact. The paper deals with certain condition of the damper characteristics that one is about various damping coefficient and another is equipped damper direction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.305-310
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• 2007

This paper presents a damper system design in torque converter to minimize the vibration in powertrain of automatic transmission vehicle. The lock-up clutch in torque converter makes engine and transmission connected directly. When the lock-up clutch is engaged the torque fluctuation of engine is attenuated by the damper system. This function decides the vehicle power-train dynamic characteristics. At first, the dynamic hysteresis effect with any self and surface to surface contact problems of the damper springs in the damper system for torque converter is analyzed by using FEM. It is shown that these simulation results have a good design reference to energy dissipation operating by damper system in torque converter. And, to calculate dynamic characteristics, the vehicle model is structured by using $AMESim^{(R)}$?? that is a common use program. The vehicle model shows the frequency response of vehicle by changing the stiffness of damper spring, and these results lead the most suitable stiffness of spring. Also, new damper system is analyzed resonance frequency variation and is compared with prior damper.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.05a
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• pp.125-130
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• 2007

Recently, the paradigms of residential planing are changing by digitalization, diversity and globalization. Since the infortance of residential living behavior and lifestyle have been recognizing, house can be perceived as a lifestyle engineering product which realizes lifestyle in a concrete way. The purpose of this research scrutinizes lifestyles through resident's value and preference of everyday living behavior in the residential, special contact. This research was conducted through the small group workshop to housewives divided into three groups such as the age 30-40s, 45-55s, 60-70s group. The workshop consisted of three stages, such as the awareness of family and home, the satisfaction of residential space, the value and preference of everyday living behavior. This study shows that Lifestyle characterize by ages, differences of living pattern and individual traits. The 30-40s' housewives relate to foster of a preschool child and it makes load of household. their characteristic is the preference of rest as releasing stresses. The 44-55s' housewives have self-oriented traits. they pursue own space and interaction with others. The 60-70s' housewives require natural interaction with family more than private space and an open view.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.96-100
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• 1998

Bakground: At our institution, We have controlled pain during vaginal delivery with epidural block since 1986. We designed a questionaire for parturients to analyze the degree of satisfaction of epidural block. Method: The self-questionaire were sent to parturients(N=200), who had epidural block to control labor pain during vaginal delivery. The questionaire covered topics dealing with motivation, fear, satisfaction and complications, of epidural block. Results: Motivation by an experienced person was 72.5%(145 parturients), fear of epidural block was 66%(132 parturients), and satisfactory response was 84%(168 parturients). Parturients who knew the role of anesthesiologist numbered 105(52.5%). Scarcely, 46 parturients displayed confidence for safety of fetus; 111 parturients experienced more than one complications. But special therapy for complications were not necessary. Conclusions: Publicity through mass-media and direct contact will improve the recognition and merit of epidural block by parturients as well as the role of the department of anesthesiology.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.66-71
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• 2011

This study analyzed the mechanical characteristics and evaluated their subsequent performance for two types of seals which reinforced characteristics with lower friction and anti-wear functions among the foremost important features in the automotive engine seals; one with the addition of glass fiber to PTFE(Polytetrafluoro ethylene); the other with the addition of self-lubricant molybdenumin addition to the glass fiber. Based on the configuration design of seal installed to the front part in the automotive engine, this study carried out interpretations on the stress and reaction for those two types of oil seals to compare the maximum stress and contact load generated from the seal steel, rubber and PTFE lip. This study also verified the stress concentration and anti-wear performance through the coefficient of friction, torque and durability test by producing two types of PTFE seals actually.

• Child Health Nursing Research
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• v.5 no.1
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• pp.18-26
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• 1999

The purpose of this study was to explore the late schooler's health concept and health behavior. The research was a descriptive method using a self-report questionaire which include semi open-ended questions. the subjects were 458 late schooler's from 4 to 6 grade. The results were as follows : 1. Perceived health concepts were ‘having no illness’ ‘having normal physical feature and strength’ ‘eating food well’ ‘take exercise’ ‘having a bright mind’ ‘having good interpersonal relationships’‘having strong will’ ‘recovering well’. 2. Perceived health behaviors to maintain health were ‘taking proper exercise’ ‘eating proper food’ ‘maintaining cleanliness’ ‘taking sufficient rest and sleep’ ‘having a vigor life and positive thought’ ‘having good interterpersonal relationships’ ‘receiving health check and immunization’. 3. Health behaviors carried out at present were ‘taking proper exercise’ ‘eating proper food’ ‘having a vigor life and positive thought’ ‘receiving health check an immunization’ ‘taking supplementary drugs’ ‘having a regular life’ ‘maintaining cleanliness’ ‘maintaining warmth’. 4. Perceived causes of illness were ‘taking inproper food’ ‘uncleanliness’ ‘insufficient warmth or environment’ ‘lack of exercise or overexertion’ ‘irregular life habits’ ‘contact with germs’ ‘mental stress’. 5. Perceived treatments of illness were ‘having sufficient rest and sleep’ ‘mental relaxation’ ‘eating food’ ‘ maintinging cleanliness’ ‘ maintaining warmth’ ‘taking supplementary drug’ ‘receiving medical treatment’.

• Journal of Electrochemical Science and Technology
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• v.5 no.4
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• pp.95-104
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• 2014

Electrochemical performance of Li-ion cells with $LiMn_2O_4$ cathodes and graphite anodes with carbonates electrolytes containing quaternary ammonium-based room temperature ionic liquids (ILs) is investigated. Eight different ILs based on tetraalkylammonium, pyrrolidinium or piperidinium cations paired with bis(trifluoromethylsulfonyl)imide or tris(pentafluoroethyl)trifluorophosphate anions are examined in combination with dimethyl carbonate as a main solvent and fluoroethylene carbonate as a solid electrolyte interface forming agent. It is shown that cycling properties of the cells are strongly affected by the content of ILs in the electrolyte mixtures and its increase corresponds to lower discharge capacity retention. Since viscosity and conductivity of ILs are of a great importance for the electrolytes formulation, some kind of combined parameter should be used for the assessment of IL applicability and calculated values of Walden products for neat ILs represent one of the possible options. Besides, positive effect of ILs on reduction of flammability and enhancement of thermal stability of electrolytes in contact with charged electrodes have been demonstrated by means of self-extinguishing time test and differential scanning calorimetry respectively.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.489-494
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• 2001

This paper develops a finite element model for frontal crash analysis of a large-sized truck. It is composed of 220 parts, 70,041 nodes and 69,073 elements. This paper explains only major parts' models in detail such as frame, cab, floor, and bumper which affect on crash analysis a lot. In order to prevent penetration not only at a part itself but also between parts, all contact areas are defined using type-36, self-impact type. The developed model's reliability is validated by comparing simulation and crash test results. The results used for model validation are vehicle pulses at B-pillar, and frame and deformation of frame and cab. The frontal crash simulation is performed with the same conditions as crash test. And, it is performed using PAM-CRASH installed in super-computer SP2. The developed model whose reliability is verified may be used as a base to develop a finite element model for occupant behavior and injury coefficient analysis.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1741-1749
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• 2001

Recent studies of the structure of wall turbulence have lead to the development of a conceptual model that validates and integrates many elements of previous models into a relatively simple picture based on self-assembling packets of hairpin vortex eddies. By continual spawning new hairpins the packets grow longer in the streamwise direction, and by mutual induction between adjacent hairpins the hairpins are strained so that they grow taller and wider as they age. The result is a characteristic growth angle in the streamwise-wall normal plane. The spanwise growth of individual packets implies that packets must either merge or pass through each other when they come into contact. Direct numerical simulations of the growth and interaction of spanwise adjacent hairpins shows that they merge by the vortex connection mechanism originally proposed by Wark and Nagib (199). In this mechanism the quasi-streamwise legs of two hairpins annihilate each other, by virtue of having opposite vorticity, leaving a new hairpin of approximately double the width of the individuals. PIV measurements in planes parallel to the wall support this picture. DNS of multiple hairpins shows how the spanwise scale doubles when the hairpins form an array.