• Korean Journal of Human Ecology
• /
• v.16 no.2
• /
• pp.421-432
• /
• 2007

The purpose of this study was to investigate the relationships between appearance-related attitude(attitude toward appearance, body satisfaction) and clothing attitude, and to examine how clothing attitude was influenced by appearance-related attitude. The method of this study was survey research by using questionnaires. Subjects were 700(middle school students 217, high school students 227, university students 256) girl students located in Junrabookdo province. In this statistical analysis, SPSS 11.5 for Windows program was utilized to calculate frequency, mean, factor analysis, cronbach's $\alpha$, one-way ANOVA, Pearson's correlation, multiple regression analysis. The results of this research were as follows: The results of analysing the factors to the response clothing attitude emerged five dimensions(fashion pursuit, gender attractiveness, self-expression, aesthetic, and modesty). University school girls' students showed higher attitude toward appearance, body satisfaction, clothing attitude except of modesty. Clothing attitude variables except of modesty had positive correlations with appearance-related attitude. However, modesty of clothing had negative correlations with appearance-related attitude. As a conclusion, adolescents' appearance-related attitude constituted important characteristics which could affect clothing attitude directly.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.4
• /
• pp.181-187
• /
• 2004

With the proliferation of nonlinear loads, high neutral harmonic currents in three-phase four-wire distribution system have been observed. It has been known that the ground impedance has an effect on the neutral currents of a system which operates with harmonics present. On-site measurements of harmonic currents and voltages according to the fall-of-potential method under case study system were made and the ground impedance modeling using the pattern search method for the harmonic analysis was developed The ground impedance model obtained by the proposed method was compared with the frequency characteristics by field tests and has shown appropriate results, and would be applicable to evaluate the harmonic and transient response characteristics of the ground system.

• Korean Journal of Oriental Medicine
• /
• v.14 no.1
• /
• pp.113-116
• /
• 2008

Petiole explant of Glehnia littoralis Fr. Schmidt was in vitro cultured MS plant medium(DUCHEFA co.) supplemented with various plant growth regulators and examined to find out their optimum combination and concentration for plantlet regeneration. We investigated optimal condition for efficient plant regeneration through adventitious shoot formation on MS plant medium with various kinds of plant growth regulators. Embryogenic calli and adventitious shoot formation were greatly influenced by plant growth regulators. Embryogenic calli induction showed a good response on MS medium supplemented with NAA and BA than others. Especially, combination of 1.0 mg/L NAA and 0.5 mg/L BA on MS medium led to the greatest frequency in adventitious shoot. The results suggest that plant regulator selection be important factor to achieve an efficient regeneration.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.3
• /
• pp.297-302
• /
• 2002

The direct torque control(DTC) of induction machines has the advantages of a simple control scheme and a very quick and robust torque response and its application is extended in the traction field. However, some drawbacks of the conventional DTC strategy using a hysteresis controller are the relatively large torque ripple in the steady state and the variation of switching frequency according to the amplitude of hysteresis bands and the motor operating conditions. In this paper, a navel direct t()roue control scheme of induction machines based on stator flux control and Space Vector Modulation Is proposed to acquire the advantage of a fixed switching period and the minimization of the torque and stator current ripple in a wide speed range. The effect of proposed method has been proven by simulations and experiments.

• Journal of Power System Engineering
• /
• v.17 no.6
• /
• pp.40-46
• /
• 2013

This paper describes the suggestion of the special seat with the auxiliary plastic member for movie theater chair. In the previous paper, we have reported on the development of foaming sponge seat with the auxiliary spring member. And we have confirmed that it was more effective on vibration transfer than the chair seat of foaming sponge only. In this study, we have examined the major design parameters needed in the development of a foaming sponge seat in which the mesh type plastic member are inserted to improve the vibration transfer effect of a chair seat. By applying experimentation to the prototype as well as the experimental modal analysis method, we made sure that the effect of the vibration transfer could be improved through the use of a mesh type plastic member as similar as the auxiliary spring member.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.9
• /
• pp.1577-1582
• /
• 2016

Now we are facing severe environmental issues such as global warming. Due to these, the concerns about eco-friendly energy have been increased. Kyoto protocol and Copenhagen climate change conference are circumstantial evidence of it. With these trends, the interests for the Electric Vehicles(EVs) which do not emit any harmful gases have gradually been raised. Unfortunately, however, massive connection of EVs to the power system could cause negative impacts such as voltage variations, frequency variations and increase of demand power. To prevent the mentioned issues, KEPCO adopts Time-of-Use(ToU) price for EVs charging. Nevertheless, it is important to verify the propriety of the charging system. In this paper, therefore, we used pre-introduced price elasticity concept to predict possible Demand Response(DR) on charging of EVs. And analyzed possible demand power increase according to various price elasticities. Simulation results show that given ToU based charging system would not enough to control the increase of demand power by EVs on the power system. It is concluded, therefore, additional methods and/or algorithms are required.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.3
• /
• pp.156-165
• /
• 1997

In the practical control systems, the dynamic range of actuatiors is limited(or saturated) when actuators are driven by sufficiently large signals. This gives rise to a nonlinearity as a result of actuator saturation. For example, the upper limit is imposed on productive capability by available factory space and capital equipment. Other examples of those kinds of actuator saturations are a maximum torque of the actua- ting motors and a throttle position in an aircraft speed control A saturating actuator may lead not only to a large overshoot during start-up and shut-down, but also to deterioration of the performance due to the uncertainties. That is, the speed of response is decreased and, possibly, the system output may not follow the lalrge reference inputs. The large-overshoot may be accompanied by rest wind-up(or called by integra- tor wind-up) which comes from controllers with integral action in saturation operation regions. Eventually, as the overshoot increases, the system has a limit cycle or becomes oscillatorily unstable. Due to these cir- cumstances, many studies are focused on the stability and robustness of the nonlinear systems with satu- rating actuator in the time-domain as well as in the frequency-domain.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.12 s.117
• /
• pp.1272-1278
• /
• 2006

This paper presents a novel MEMS condenser microphone with rigid backplate to enhance acoustic characteristics. The MEMS condenser microphone consists of membrane and backplate chips which are bonded together by gold-tin(Au/Sn) eutectic solder bonding. The membrane chip has $2.5mm{\times}2.5mm$, 0.5${\mu}m$ thick low stress silicon nitride membrane, $2mm{\times}2mm$ Au/Ni/Cr membrane electrode, and 3${\mu}m$ thick Au/Sn layer. The backplate chip has $2mm{\times}2mm$, 150${\mu}m$ thick single crystal silicon rigid backplate, $1.8mm{\times}1.8mm$ backplate electrode, and air gap, which is fabricated by bulk micromachining and silicon deep reactive ion etching. Slots and $50{\sim}60{\mu}m$ radius circular acoustic holes to reduce air damping are also formed in the backplate chip. The fabricated microphone sensitivity is 39.8 ${\mu}V/Pa$(-88 dB re. 1 V/Pa) at 1 kHz and 28 V polarization voltage. The microphone shows flat frequency response within 1 dB between 20 Hz and 5 kHz.

• Journal of the korean society of oceanography
• /
• v.38 no.3
• /
• pp.122-134
• /
• 2003

Low-pass filtered time series of wind, coastal temperature, sea level and current were analyzed to understand the coastal upwelling processes in the southeast coast of Korea. Southerly winds favorable for coastal upwelling were dominant in summer of 1997. Total period of four major wind events amounts to 58 days during one hundred days from June to early September. Coastal temperature is most sensitive to variations of wind. The time lag between the onset of southerly (northerly) winds and decrease (increase) of temperature is 3-18 hours. In the frequency domain the coherent bands have periods of 2.4 and 4.0-5.4 days with respective phase lags of 17 and 27-37 hours. Despite the sensitive response, the magnitude of temperature change is not quantitatively proportional to the intensity or duration of the wind, because it depends on the degree of baroclinic tilting of isotherms built dynamically by the strong Tsushima Warm Current (TWC). Current is particularly strong near the coast and has a large vertical shear during the upwelling periods, which is associated with the baroclinic tilting. Both of current and sea level are poorly coherent with wind or temperature except for the period of 4 days.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.10
• /
• pp.1062-1068
• /
• 2009

In this study, the impact force levels of bang machine and impact ball were measured, then the heavy-weight impact sounds generated by the bang machine and impact ball were investigated. It was found that the heavy-weight impact sources generated through modal excitation, and the impact force of the impact ball was similar to that of real impact source. The heavy-weight impact sounds were also measured in the real apartments with different slab thickness and floor structures. The results showed that the floor impact sound levels in terms of $L_{iFmax,AW}$, generated by impact ball sounds were reduced by using the resilient isolators. The frequency characteristics of heavy-weight impact sounds at 125 and 250 Hz were consistent with the characteristics of impact force spectrum. However, the difference between the impact sounds and the impact forces were found at 63 and 500 Hz due to the resonance of the floor structure and flanking noise, respectively.