• Earthquakes and Structures
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• v.22 no.6
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• pp.625-635
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• 2022

High-rise buildings (HRBs) are considered one of the most common structures nowadays due to the population growth, especially in crowded towns. The lack of land in crowded cities has led to the convergence of the HRBs and the absence of any gaps between them, especially in lands with weak soil (e.g., liquefaction-prone soil), but then during earthquakes, these structures may be exposed to the risk of collision between them due to the large increase in the horizontal displacements, which may be destructive in some cases to the one or both of these adjacent buildings. To evaluate methods of reducing the risk of collision between adjacent twin HRBs, this research investigates three vibration control methods to reduce the risk of collision due to five different earthquakes for the case of two adjacent reinforced concrete (RC) twin high-rise buildings of 15 floors height without gap distance between them, founded on raft foundation supported on piles inside a liquefaction-prone soil. Contact pounding elements between the two buildings (distributed at all floor levels and at the raft foundation level) are used to make the impact strength between the two buildings realistic. The mitigation methods investigated are the base isolation, the tuned mass damper (TMD) method (using traditional TMDs), and the pounding tuned mass damper (PTMD) method (using PTMDs connected between the two buildings). The results show that the PTMD method between the two adjacent RC twin high-rise buildings is more efficient than the other two methods in mitigating the earthquake-induced pounding risk.

• Korean Journal of Social Welfare
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• v.51
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• pp.29-61
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• 2002

This study was designed to find out the determinants of types of bullying behavior, and the effects of types of bullying behavior on the bullies. For this purpose, a hypothetical model which explains the relationships among 6 environmental factors, 5 types of bullying behavior, and 5 outcome variables for the bullies was developed. Using the data collected from 177 junior and high school students who have bullied the other students, the hypothetical model was tested. For data analysis, a path analysis was used, and the best-fitting model was found (df=78, GFI=0.953, CFI=1.00). As a result of analyzing the model, types of bullying behavior were found to be determined by the different environmental factors: Isolation was determined by 2 factors (feeling of isolation from friends, exposure to bullying), social bullying by 2 factors (lack of support from parents, exposure to bullying), verbal bullying by conflicts with parents, physical bullying by 3 factors (lack of support from parents, exposure to isolation and exposure to bullying), and instrumental bullying by lack of support from parents. On the other hand, the pleasure that the bullies feel after bullying behavior was increased by isolation, verbal bullying and physical bullying, while decreased by instrumental bullying. Guilt feeling was decreased by isolation and instrumental bullying, while increased by physical bullying. Isolation increased the tendency of blaming the victim. Isolation and instrumental bullying increased bullies' self-esteem, while social bullying decreased self-esteem. Verbal bullying increased the extent of bullying, while instrumental bullying decreased the extent of bullying. Based on the findings, the intervention strategies to change the bullies' attitudes toward victim, and to increase social support from the significant others as well as the effective ways to reorganize the school environment in order to reduce and prevent bullying behavior were suggested.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.9
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• pp.25-33
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• 2007

In this paper, the high isolation and wideband 94 GHz MIMIC(Millimeter-wave Monolithic Integrated Circuit) single balanced cascode mixer was designed and fabricated. Also, we designed and fabricated a 3 dB tandem coupler which has a high isolation and wideband characteristic. The single balanced resistive mixer which does not require an external IF balun was designed using the 0.1 ${\mu}m$ InGaAs/InAlAs/GaAs metamorphic HEMT(High Electron Mobility Transistor). The DC characteristics of MHEMT's are 665 mA/mm of drain current density, 691 mS/mm of maximum transconductance. The current gain cut-off frequency($f_T$) is 189 GHz and the maximum oscillation frequency($f_{max}$) is 334 GHz. A 94 GHz single balanced cascode mixer was fabricated using our 0.1 ${\mu}m$ MHEMT MIMIC process. From the measurements, the fabricated couplers showed wideband characteristics. The conversion loss of single balanced cascode mixer was 9.8 dB at an LO power of 10.9 dBm. The LO to RF isolation of single balanced cascode mixer was 29.5 dB at 94 GHz. We obtained in this study a higher LO-RF isolation compared to some other single balanced mixers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.409-412
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• 2000

A high performance EEG signal measurement system is fabricated. It consists of high precision pre-amplifier and auto identification bandwidth unit. High precision pre-amplifier is composed of signal generator, signal amplifier with a impedance converter, body driver and isolation amplifier. The pre-amplifier is designed for low noise characteristics, high CMRR, high input impedance, high IMRR and safety, Auto identification bandwidth unit is composed of AD-converter and PIC micro-controller for real time processing EEG signal. The performance of EEG signal measurement system has been shown the classified bandwidth through the clinical demonstrations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.102-110
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• 2002

In this paper, we present the fabrication of tunable capacitors and 3-dimensional inductors. This work was related to fabricated 3-dimensional device for need of micro device in developing new intelligence age. This device was fabricated by electroplating used electroplating PR and high-vacuum evaporation of metal. Fabricated micro-inductor is consisted of air-bridge on electroplating rod and electroplated core. Micro-capacitor is consisted of thin metal membrane and electroplated core. Electroplating material is used Cu metal solvent. Air-gap between metal-layers function as almost perfect isolation layer. The most advantage of our micro-inductor and micro-capacitor compared to present device is a possibility that can fabricate on RF MEMS(microelectro-mechanical systems) application with high performance and various function. In this paper, we present the fabrication of tunable capacitors and 3-dimensional inductors. This work was related to fabricated 3-dimensional device for need of micro-device in developing new intelligence age. This device was fabricated by electroplating used electroplating PR and high-vacuum evaporation of metal. Fabricated micro-inductor is consisted of air-bridge on electroplating rod and electroplated core. Micro-capacitor is consisted of thin metal membrane and electroplated core. Electroplating material is used Cu metal solvent. Air-gap between metal-layers function as almost perfect isolation layer. The most advantage of our micro-inductor and micro-capacitor compared to present device is a possibility that can fabricate on RF MEMS application with high performance and various functions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.165-171
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• 2004

In this paper, the modeling and design of high-Q multilayer passives have been investigated, and multilayer diplexer for GSM/DCS applications has been designed and fabricated using the passives. Modeling of a multilayer inductor was performed by the subsystems of distributed components, and using the modeling the optimal structures of the high-Q multilayer inductor could be designed by analyzing parasitics and couplings which affect their frequency characteristics. Multilayer diplexers for GSM/DCS applications have been designed and fabricated using LTCC technology. LPF for GSM band had the passband insertion loss of less than 0.55 dB, the return loss of more than 12 dB, and the isolation level of more than 26 dB. HPF for DCS band had the passband insertion loss of less than 0.82 dB, the return loss of more than 11 dB, and the isolation level of more than 38 dB.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.53-60
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• 2009

Isolated structures use devices such as high damping rubber bearings (HDRB) in order to dramatically reduce the seismic forces transmitted from the substructure to the superstructure. The laminated rubber bearing is the most important structural member of a seismic isolation system. The basic characteristics of rubber bearings have been confirmed through compression tests, compressive shearing tests and creep tests. This paper presents the results and analysis of a 1000hr, ongoing creep test conducted at 7.5MPa, 8.37MPa in our laboratory. The long-term behavior of bridge bearings, such as high-damping rubber bearings, will be discovered through a compression creep test subjected to actual environmental conditions. These tests indicated that the maximum creep deformation is about $0.3{\sim}1.92%$ of total rubber thickness.

• Journal of IKEEE
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• v.26 no.4
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• pp.584-589
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• 2022

For DC-AC power conversion from a high-voltage photovoltaic panel to a single-phase grid, the two-stage transformerless inverter with a buck-boost converter followed by a full-bridge inverter is widely used. To avoid an excessive leakage current due to the large parasitic capacitance of the photovoltaic panel, the full-bridge inverter can only adopt the bipolar PWM which results in much higher power loss compared to the unipolar PWM. In order to overcome such a poor efficiency, this paper proposes a new topology in which an IGBT and a diode for circuit isolation are added to the buck-boost converter. The proposed circuit isolation method allows the unipolar PWM in the full-bridge inverter without any increase in the leakage current so that the overall efficiency can be improved. The validity of the proposed solution is verified by computer simulation and power loss calculation.

• Journal of Life Science
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• v.8 no.6
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• pp.711-722
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• 1998

This study was undertaken to determine the antimicrobial susceptibilities of 716 bacterial strains among 1,104 microbes which were isolated in blood culture from 13,595 in-patients and out-patients in K hospital during the pe-riod of 1993 to 1996. The results obtained were as follows : The isolation rate of microbes from the blood culture for 3 years was 8.1% (1,104/13,595). Among 716 bacte-rial strains, Escherichia coli and Staphylococcus epidermidis were 29.8% (213) and 19.5% (140) respectively. The bacterial isolation frequency according to ages was high at fifties, sixties and two or less years old groups, especially the isolation rate of S. epidermidis was 47% at two or less years old group and that of Salmonella typhi was 36% at thirties years old group. The seasonal isolation rate of the bacterial species except E. coli was high during May to September. Gram positive cocci were resistant to penicillin-G except Enterococcus faecalis, but susceptible to vanco-mycin and teicoplanin. Gram negative bacilli were susceptible to amikacin, ciprofloxacin, and imipenem, but resistant to ampicillin except S. typhi. These results indicate that bacterial strains isolated from bacteremia patients were resis-tant to penicillins, but susceptible to vancomycin, teicoplanin, amikacin, ciprofloxacin and imipenem.

• Journal of Korean Academy of Nursing
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• v.6 no.1
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• pp.72-79
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• 1976

Contemper nursing literature place much importance on human- centered and individualized care. Nursing research has related stress during hospitalization of adolescent patients to adaptation to a new environment, isolation from friends, limitation due to illness, over protection of parents and communication with member of the medical team. The investigator conducted this study in the hope that an understanding of adolescents responses to hospitalization, their perceptions, the kinds and levels of stress, and the relationships between stressors and individual characteristics would contribute to the improvement of adolescent patient care. The objective of the study was to obtain informations related to the adolescents psychological stress experience during hospitalization, specifically stress from interpersonal relationships and communication, isolation from the family, social or economic problems, illness and from the treatment environment and nursing care. An interview schedule adopted from Holmes and Rahe's Social Readjustment Rating Scale and selected items from Voicer's instrument on stress-producing events was used with 120 adolescent inpatients aged 13 to 18 years three general hospitals in Seoul during Aug. 10, to Sep. 30, 1975. 1. The sample consisted of 66 male and 54 female patients. Sixty-six percent were late adolescents, aged 16 to 18 years: 4% were early adolescents, aged 13 to 15 years. The primary cause for hospitalization was for orthopedic problems (35.8%). More than half of these (54.4%) were due to injury or accident. 2. Stress eclated to illness revealed the highest score (4.97), followed by stress related to treatment environment and nursing care (4.34) , isolation from family and social or economic problems (4.01) and interpersonal relationships and communication (3.96). 3. The perceived indifference of doctors and nurses was a serious cause of stress (mean=4.83). Fellow patients and visitors caused least stress (mean=2.06). 4. Discontinuation of education or unemployment were major stressful events (mean=4.71). Least stressful was isolation from the family (mean=3.47). 5. More than 94% of the respondents expressed fears related to body image (mean=4.97) 6. Within the category of treatment environment and nursing care, items related to restrictions because of treatment, discomfort because of treatment, inadequate explanation from nurses about procedures were rated as severe stress events (mean=4.6). Items related to the ward environment and to having a relative stay with them were seen by the group as less serious events (mean=3.7). 7. Stress related to interpersonal relationships and communication was correlated positively with female patients and those preferring passive activities. (P〈0.05) 8. Stress related to family problems was positively related to female and early adolescent patients (P< 0.05). Stress related to social problems was positively , elated to students and those preferring active pursuits (P< 0.05). 9. There were no correlation between the high stress related to disease and any of the characteristic items. (P> 0.05) 10. Stress related to treatment environment and nursing care was positively related of early adolescent and female and student patients. (P< 0.05) This group of hospitalized adolescents reported high level of stress related to treatment environment and nursing care, due to lack of consideration of normal growth and development and individual characteristics. The findings have important implications for the planning of effective, individualized, comprehensive nursing care of adolescents during hospitalization.