• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.10
• /
• pp.900-906
• /
• 2010

This note proposes vibration-free motor control through modified LQG/LTR methodology. A conventional LQG/LTR method is a design tool in the frequency domain. However, unlike the conventional one, the proposed one is a time response based design method. This feature is firstly designed by parameterized settling time control gain through the target loop design procedure and the feature is secondly realized by loop transfer recovery. In order to show convergence to the target loop transfer functions, asymptotic behaviors of the open and the closed loop transfer functions are shown. At the conclusion, it is verified that the proposed method is robustly stable to parametric uncertainties through ${\mu}$-plot.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.12
• /
• pp.1184-1189
• /
• 1995

The rapid quenching dynamics of F center excitation by OH- defects in KCl crystals are investigated by monitoring ground state absorption bleach recovery, using a picosecond streak camera absorption spectrometer. F center absorption bleach in OH--doped crystals shows three distinguishable recovery components with the current temporal resolution, designated as slow, medium and fast components. The slow one is due to the normal relaxation process of F* centers as found in OH--free crystals. The others are consequent on energy transfer from electronically excited F centers to OH--vibrational levels. The fast component is a minor energy transfer process and resulting from the relaxation of somewhat distant, not the closest, associated pairs of F* and OH- defects. The energy transfer between widely separated F* and OH- defects opens up a recovery process via the medium component which is assisted by OH- librations, lattice vibrations and OH- dipole reorientations. The quenching behaviors of F* luminescence and photoionization by OH- are explained well by the relaxation process of the medium component.

• Journal of the Korean Society of School Health
• /
• v.15 no.2
• /
• pp.167-182
• /
• 2002

The purpose of this study was to examine the factors related to adolescence' post-sexual assault attitudes and behaviors. 906 students from 5girls high schools completed self-reported questionnaires. Independent variables are sexual attitudes, rape myth acceptance, perceived importance of sexuality education, parent sexuality education, parent closeness, parent superintendence, family functioning and socioeconomic variables. The data were analyzed by Factor Analysis, Correlation Analysis, Stepwise Multiple Regression Analysis using SPSS program. The significant influencing factors were home sexuality education, perceived necessity & importance of sexuality education, parent closeness, parent superintendence, family functioning, grade, vocational school, rape myth(rapists are mentally ill, dating partner would not be rapist. rapists are stranger), sexual attitudes(sexual permissiveness, gender equality, family planning, STDs & prostitution, marriage and divorce and abortion), and dating experience. Examination of barriers to post-sexual assault coping behaviors and attitudes is critical component of victim recovery and rape prevention. This study would gives basic information to the effective prevention and coping program development related to sexual assault.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.742-745
• /
• 2001

Plastics are one of difficult materials for recycling due to their characteristics in use. Recycling ratio of waste plastics was around 40% in last year in Japan, which includes energy recovery. Feed stock recycling and mechanical recycling are not easy because of additives in commercial plastics. Then, pyrolysis treatments have been done to recovery energy. Although plastics are easy to fire, complete combustion of them is not easy if anti-firing agents are added especially. Therefore, researches on pyrolysis or combustion behaviors of plastics containing additives are important from a view point recycling of plastics. Direct observation of popular plastics like polystyrene (PS), polycarbonate (PC), polyphenyle ether (PPE) and polyvinyl chloride (PVC) to investigate their pyrolysis behaviors in the present study. In case of PS, melting and gas evolution started at 9$0^{\circ}C$ and 39$0^{\circ}C$ respectively. And combustion finished at 445$^{\circ}C$. On the other hand, more than $600^{\circ}C$ and sufficient oxygen are required for complete combustion of PC and PPE.

• Korean Journal of Adult Nursing
• /
• v.26 no.2
• /
• pp.203-213
• /
• 2014

Purpose: The purpose of this study was to understand and describe the every day life experience of patients with acute myocardial infarction (AMI) during the recovery period after Percutaneous Coronary Intervention (PCI) using a qualitative approach. Methods: Twelve patients with AMI participated in this study. Their age ranged from 42 to 75. The data were collected by individual in-depth interviews and all interviews were audio-taped and transcribed verbatim. The transcribed data were analyzed using traditional qualitative content analysis. Results: Six sub-themes emerged from the data as follows: Getting to know about illness, getting motivated for health behavior, putting an effort into health behavioral change, having difficulties maintaining health behavior, setting up coping strategies for health behavior and having a need for a tailored education. The results of this study showed how the health behaviors of patients with AMI are related to their every day life experiences. Conclusion: The results of this study could help health professionals to better understand patients with AMI and design effective educational interventions to improve their health behaviors.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.1
• /
• pp.462-473
• /
• 2019

The effects of the location and dimension of the gate, location, and volume of the feeder, application of a chill, chill volume, and heating method of the feeder with respect to the effect of the mold-designing technologies on the defect status of the products are described. It is possible to increase the solidification time of the feeder by heating feeder. Furthermore, the pressure generated from the feeder is imposed on a product, and this decreases the generation of shrinkage porosities. In this study, two types of gating and feeding systems had been proposed: the bottom L-type junctions and the top L-type junctions. Additionally, solidification behaviors, such as solidification time, shrinkage porosities, weight percentage of chill system to product, hot spot, and solidification time ratio (=Solidification time of feeder/solidification time of product), are extensively analyzed by using commercial casting simulation software. Based on the solidification behaviors, reasonable mold design, feeding system, critical feeder heating temperature, and solidification time ratios are proposed in the sand casting process for the fabrication of carrier housing in order to reduce the casting defects and to increase the recovery rate.

• Journal of the Korean Society for Heat Treatment
• /
• v.21 no.6
• /
• pp.307-313
• /
• 2008

The tensile deformation and shape recovery behaviors were studied in Ni-Ti shape memory wires showing different transformation characteristics by annealing at $200{\sim}600^{\circ}C$. Both R phase ${\rightarrow}$ B19' martensitic transformation at lower temperature and B2 ${\rightarrow}$ R phase transformation at higher temperature occurred in the shape memory wires annealed at $200{\sim}500^{\circ}C$. Transformation temperature and heat flow of B19' martensite increase but those of R phase main almost constant even with increasing annealing temperature. In the case of wires annealed and then cooled to $20^{\circ}C$, plateau on stress-strain curves in tensile testing can be observed due to the collapse of R phase variants and the formation of deformation-induced B19' martensite. In the case of wires annealed and then cooled to $-196^{\circ}C$, however, plateau on stress-strain curves does not appear and stress increases steadily with increasing tensile deformation. Comparing shape recovery rate with cooling temperature after annealing, shape recovery rate of the wire cooled to $20^{\circ}C$ is higher than that of the wire cooled to $-196^{\circ}C$ after annealing, and maximum shape recovery rate of 95% appears in the wire annealed at $400^{\circ}C$ and then cooled to $20^{\circ}C$. $R_s$ and $R_f$ temperatures measured during shape recovery tests are higher than $A_s$ and $A_f$ temperatures measured by DSC tests even at the same annealing temperature.

• Journal of Korean Academy of Nursing
• /
• v.22 no.3
• /
• pp.297-315
• /
• 1992

Caring has been identified as the essence and unifying domin of nursing(Leininger). Many nurses believe that the art of nursing is comprised of actions that are predominantly caring in nature. Although caring has been the traditional ideology of nurses, it is only now beginning to emerge as the central construct for the development of nut sing research, theory and practice. The problem addressed by this study was to identify how hospitalized children and their nurses express the meaning of caring, how they think nurses should care for children and to describe their experiences of being cared for. The purpose was to provide theoretical understanding of caring as perceived in Korea to contribute to the development of Korean nursing knowledge. The subjects were 76 hospitalized children admitted to pediatric units in five teaching hospitals and 66 nurses who were caring for these children. In this descriptive study, data were collected from Nov 11, 1991 to Jan 30, 1992 by interviews and an open-ended questionnaire and analysed by van Kaam's method. Caring themes perceived by the children and their nurses were classified into eight categories, -helping, comfort, love, warmth(only by children), recovery from illness, health maintenance (only by nurses), presence, nurturance and responsibility. Ideal caring behaviors perceived by the children and their nurses were six categories, -to give help, provide comfort, give love, stay with, treat warmly and aid recovery. Subcategories of giving help were promptness and competence, detailed explanations and support and encouragement. Other subcategories of giving help reported only by nurses were individualizing care, recognizing needs and providing a familiar enviornment. Subcategories of maintaining comfort were making comfortable, alleviating pain ; one subcategory reported only by children was consolating. A subcategory of giving love was concern, two subcategories reported only by nurses were compassion and respect. Subcategories of staying with were playing with and touching : only nurses reported empathy, Subcategories of treating warmly were tenderness and kindness. In the experience of caring, there were 4 categories, -to give help, stay with, show concern and provide comfort. Both the hospitalized children and their nurses had experienced caring primarily from their mothers. Mothers' caring behaviors were direct, personal, basic, supportive nursing acts. On the other hand, nurses caring behaviors were task oriented skilled procedures and medically delegated acts. This study contributes understanding of the complexity of caring, more specifically the meaning and experience of caring and ideal caring behaviors. Research may be able to move into verification when instruments are developed to measure the complexity of caring beliefs, values and behaviors in Korea and other cultural settings.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.03a
• /
• pp.187-194
• /
• 2002

Bridge dynamic behaviors and the failure of the foundation are examined in this study under seismic excitations including the local scour effect. The simplified mechanical model, which can consider the effect of various influence elements, is proposed to simulate the bridge motions. The scour depths around the foundations are estimated by the CSU equation recommended by the HEC-18 and the local scour effect upon global bridge motions is then considered by applying various foundation stiffness based upon the reduced embedded depths. From the simulation results, it is found that seismic responses of a bridge with the same scour depth for both foundations increase due to the local scour effect. The bridge scour is found to be significant under weak and moderate seismic intensity. The recovery durations of the foundation stiffness after local scour are found to be critical in the estimation of the probability of foundation failure under earthquakes. Therefore, the safety of the whole bridge system should be conducted with the consideration of the scour effect upon the foundations and the recovery duration of stiffness should be determined rationally.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.5
• /
• pp.437-443
• /
• 2013

Clathrate samples, using hydroquinone as a host and ethylene or propylene as a possible guest, were prepared and analyzed by means of spectroscopic measurements. Obtained results showed that ethylene can form clathrate compounds with hydroquinone at 4.0MPa and room temperature, while propylene cannot form clathrate compounds. Different formation behaviors of these two olefin compounds can be applied to a clathrate-based storage/recovery of ethylene in a selective way, and can provide useful information on the cavity size of the formed clathrate compounds.