• Earthquakes and Structures
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• v.9 no.1
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• pp.73-91
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• 2015

The effectiveness of tuned mass dampers (TMDs) in reducing the seismic response of civil structures is still a debated issue. The few studies regarding TMDs on inelastic structures indicate that they would perform well under moderate earthquake loading, when the structure remains linear or weakly nonlinear, while tending to fail under severe ground shaking, when the structure experiences strong nonlinearities. TMD seismic efficiency should be therefore rationally assessed by considering to which extent moderate and severe earthquakes respectively contribute to the expected cost of damages and losses over the lifespan of the structure. In this paper, a method for evaluating, in a life-cycle cost (LCC) perspective, the seismic effectiveness of TMDs on inelastic building structures is presented and exemplified on the SAC LA 9-storey steel moment-resisting frame benchmark building. Results show that the LCC concept may provide an appropriate alternative to traditional performance criteria for the evaluation of the effectiveness of TMDs and that TMD installation on typical existing middle-rise buildings in high seismic hazard regions may significantly reduce building lifetime cost despite the poor control performance observed under the most severe seismic events.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.387-393
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• 2001

Installing vibration control devices in the structure rises as a solution instead of increasing structural strength considering construction cost. Especially, viscoelastic dampers show excellent vibration control performance at low cost and are easy to install in existing structures compared with other control devices. Therefore, cost-effectiveness of structure with viscoelastic dampers needs to be evaluated. Previous cost-effectiveness evaluation method for the seismically isolated structure(Koh et al., 1999;2000)is applied on the building structure with viscoelastic dampers, which combines optimal design and cost-effectiveness evaluation for seismically isolated structures based on minimum life-cycle cost concept. Input ground motion is modeled in the form of spectral density function to take into account acceleration and site coefficients. Damping of the viscoelastic damper is considered by modal strain energy method. Stiffness of shear building and shear area of viscoelastic damper are adopted as design variables for optimization. For the estimation of failure probability, transfer function of the structure with viscoelastic damper for spectral analysis is derived from the equation of motion. Results reveal that cost-effectiveness of the structure with viscoelastic dampers is relatively high in how seismic region and stiff soil condition.

• Architectural research
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• v.1 no.1
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• pp.47-53
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• 1999

An interesting of desktop air-conditioning system is the Personal Environmental Module(PEM) System. The PEM system allows the occupant to choose the desired temperature, air volume and direction of the discharged air. In this study, the measurements on the age of air and the air change effectiveness, using the tracer gas method, are carried out to analyze the ventilation performance for provision of fresh air near the breathing zone by the PEM. The relations between the PEM for optimal control and other factors related to indoor air quality, and the ventilation for the PEM are examined. Also, three different supply diffuser types(desktop, floor and ceiling) are compared in view of their ability to distribute supply air to the workstation breathing zone. The desktop diffuser type could deliver air directly to the occupants breathing zone with a high degree of effectiveness. The minimum local age of air was measured in the breathing zone, which is directly supplied with air from the PEM diffusers, and the measured local air change effectiveness of the desktop diffuser in the breathing zone was about 1.13 to 1.23 times greater than that of the ceiling and floor diffusers. When the minimum outside air change rate as specified using ASHRAE Standard 62R is supplied with a desktop diffuser type, the volume of outside air can be reduced 13 to 23%, resulting in a commensurate in ventilation energy use.

• The Journal of Information Systems
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• v.17 no.4
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• pp.129-156
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• 2008

This study empirically tested a research model and hypothesis extracted and based on IT governance and knowledge sharing theories. In this study we targeted CIO and IS managers to find the effects of the degree of knowledge sharing between CEO and CIO regarding five areas of IT governance decision-making: IT principles, IT architecture, IT infrastructure, business application needs, and IT investment and prioritization, on IT and business alignment. Additionally we studied the effects of business alignment on the effectiveness of information systems. Results showed that the degree of knowledge sharing in CEO and CIO on IT principles, IT infrastructure, IT investment and prioritization had a positive influence on IT and business alignment, ultimately showing a positive influence on the effectiveness of information systems. This research has shown that fording the preferable relationship between IT and business affected by performing high quality decision making based on knowledge sharing and consequently it also is a basis to provide a positive influence to the effectiveness of the information system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.305-309
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• 2008

This experimental study has been conducted to investigate the installation of the vertical flame holder shape in ramjet combustor, which affects on the film cooling effectiveness. All slot position, the film cooling effectiveness decreases because of the shear layer and high turbulence intensity between separated flows and coolant flows. When the flame holder is installed, film cooling effectiveness decreases abruptly on the beginning of the slot exit region due to the mixing effect. As the blowing rate increases, the film cooling effectiveness is increased for all cases due to the augmented momentum of injected coolant from the slot.

• Journal of Sasang Constitutional Medicine
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• v.15 no.3
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• pp.124-138
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• 2003

Objectives : To evaluate the properness and effectiveness of the question categories concerning 'sasang constitutional characteristics of mind', used in Iksan Wonkwang Oriental Medicine. Methods : We statistically analyzed data from those 1335 patients focussing on 'relative discrimination ability' to sasang constructions and 'response ratio'. Patients included in this research are only those who had been well treated in Iksan Wonkwang Oriental Medicine during the Period of three years from 2000 to 2002. The data are obtained through the electronic chart developed by Kim Jong-Yeal, and analyzed using the statistical Package SPSS. Results: In total characteristics of mind, the question category of 'timid' has high discriminating power and effectiveness to Soeum type, more in women than men, and especially with an age of 21 or more; The category of 'hasty-tempered' to Soyang type in women with all ages and men with ages 21-40; The category of 'broad-minded' to Taeum type with ages 41 or more; The category of 'timid and broad-minded' to Soyang type, and especially high to women with ages 41 or more. Question categories concerning response type in anger were estimated to have different response patterns to sasang constructions only for ages 21 or more by $X^2$2 test. The question category of 'bear and last long' has high discriminating power and effectiveness to Soeum type, more in men than women, and increasingly to ages; The category of 'impatient and disarmed quickly' to Soyang type in both women and men, especially with ages 21 or more; The category of 'impatient' to Soyang type women or with ages 21 or more. Other categories have low discriminating power or low effectiveness. Concernig expression type of one's thought, the question category of 'straightly' has high discriminating power and effectiveness to Soyang type, more in wemen than men, and especially to ages 21 or more; The category of 'tender' to Soeum type, in women or with ages 40 or less; The category of 'indirectly' to Taeum type in men or with ages 41 or more; The category of 'straightly and stuborn' to Soyang type with ages 41 or more; The category of 'indirectly and tender' to Soeum with with ages 20 or less; The category of 'not express and tender' to Soeum type with ages 41 or more; Conclusions : Question categories concerning total characteristics of mind, response type in anger and expression type of one's thought, are partially discriminating and effective to specific constitution according to sex and ages, and some categories are more discriminating and effective when they are composited. But generally, the discriminating power of Taeum constitution group and group with ages 20 or less was too low, so it is necessary to develope question categories for those groups.

• Korean Security Journal
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• no.14
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• pp.449-464
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• 2007

The Guard might focus on a king's personal safety in the wake of the system of the Silla and Taebong dynasties until the establishment of the Goryeo Dynasty's unique political system. The purpose of this research is to examine gob characteristics and organizational effectiveness of security guard on martial arts of security service guard. The subjects of this study are private guard as working security companies of Seoul and Kyongi area and 250 persons. It was a method of questionnaire for this study and used a questionnaire developed by Hackman and Oldham(1976) for gob characteristics and used a questionnaire developed by Tymon(1988) for organizational effectiveness that translated and modified from Kim, Ilsoon and measured by 5 point likert. It used to analyze the data for one-way ANOVA and multiple regression analysis. There are conclusions of this study. First, there was a partially difference on god characteristics and organizational effectiveness of population statistical character. Depending on sex, 'female' group was high, depending on the age, '46 year-old+ group' was high, depending on the educational level, 'bachelor group' was high, depending on the income, '400manwon+ group' was high. Second, it becomes positive result to the period, the frequency and the intensity of security martial arts practice. Third, it happened that gob characteristics is increase and organizational effectiveness is also positive way.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.2
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• pp.151-161
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• 2019

In this study, to evaluate the High Altitude Electromagnetic Pulse(HEMP) protection performance of UHPC/CNT composites by the content of Carbon nanotubes(CNTs), Electromagnetic Shielding Effectiveness(SE) test was performed based on MIL-STD-188-125-1. And the results were verified by applying the Antenna theory. In the case of UHPC with a thickness of 200 mm mixed with 1 % CNT of cement weight, the SE was 28.98 dB at 10 kHz and 45.94 dB at 1 GHz. Then the Scabbing limit thickness for bullet proof was computed based on the result of compressive strength test which was 170 MPa, and it was examined whether it satisfied the HEMP protection criteria. As a result, the required HEMP shielding criteria were satisfied in all frequency ranges as well as the scabbing limit thickness was reduced by up to 43 % compared with that of ordinary concrete.

• Journal of Engineering Education Research
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• v.25 no.5
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• pp.68-74
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• 2022

The purpose of this study was to develop an infographic-based STEAM program for high school students and test its effectiveness. In this study, we converged high school 'art' education with 'Korean language' and 'mathematics.' The program was divided into four phases. The effectiveness of the program was analyzed by conducting matched pair t-test for 377 students at a girl's high school in Seoul before and after the program. The study found that the students' self-concept on mathematics and their attitude towards choosing science and engineering career showed significant increases after the program. By connecting high school courses through data visualization based on cognitive information design, findings from this study suggest that our infographic-based STEAM program should be implemented more frequently at high schools.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.7
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• pp.953-964
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• 1999

The purpose of this study was to analyze the effectiveness of negative appeal ads taking social problems as their themes. Two social problem ad themes concerning abortion and drug addiction were selected as stimulus. Questionnaires consisted of questions about affective response cognitive evaluation consumer's characteristics(sex, clothing involvement social problem involvement) and the ad and brand attitudes They were distributed to 200 high school students in Seoul. Results were : 1 The affective response consisted of 4 dimensions(negative inactivating activating positive) and the cognitive evaluation had 3 dimensions(utility·persuasive power creativity awareness) 2. Creativity and awareness dimensions and the ad attitude had positive influence on the brand attitude for the abortion theme ad,. Creativity dimension and consumer's clothing involvement had positive influence on the brand attitude for the drug addiction theme ad . Especially the affective response had no significant influence on the brand attitude. This result suggests that in case of negative appeal ads the affective response does not necessarily degrade the brand attitude while positive cognitive evaluation on creativity and awareness of the could influence the brand attitude favorably through raising attention to the brand resulting in high effectiveness of the ad.