• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.103-110
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• 2020

In the recent seismic design code KDS 41 17 00, selection and modification procedures of ground motions which are used for nonlinear dynamic analyses were adopted. However, its practical applications are still limited due to the lack of literatures. This paper introduces case studies which used site-response analyses to select and modify ground motions for nonlinear dynamic analyses. Based on the case studies, design criterion for site-response analyses were reviewed thoroughly in the viewpoint of practical applications. It was found that design requirements related with bedrock motions are too conservative that ground motions are selected and modified in the excessive manner. It is especially true for low-rise building structures with period ranges including acceleration-sensitive regions. Even though surface motions have shown appropriate responses, such building structures have to re-select and re-modify ground motions based on pre-analysis procedures rather than post-ones according to the current seismic design code. Also, it was observed that building structures with soft soils under strong ground motions need more comprehensive investigations on soil properties and efficient analysis methods in order to perform site-response analyses. This is due to the fact that lack of reliabilities on soil properties and analysis methods could result in unstable site-responses.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.5
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• pp.47-56
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• 2008

This study was performed to evaluate the effect of Response modification factors (R-factor) in 3-, 9- and 20- story steel Moment Resisting Frame (MRF) buildings. Each structure was designed using a R-factor of 8, as tabulated in the 2000 International Building Code provision (IBC 2000) and Korea Building Code (KBC) 2008. In order to evaluate the maximum and minimum performance expected for such structures, an upper bound and lower bound design were adopted for each model. Next, each analytical model was designed using different R-factors (8, 9, 10, 11, 12) and four different structural periods with the original fundamental period. For a detailed case study, a total of 150 analytical models were subjected to 20 ground motions representing a hazard level with a 2% probability of being exceeded in 50 years. In order to evaluate the performance of the structures, static push-over and non-linear time history analysis (NTHA) were performed, and displacement ductility demand was investigated to consider the ductility capacity of the structures. The results show that the dynamic behaviors for the 3- and 9-story buildings are relatively stable and conservative, while the 20-story buildings show a large displacement ductility demand due to dynamic instability factors. (e.g. P-delta effect and high mode effect)

• Journal of Life Science
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• v.17 no.12
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• pp.1744-1753
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• 2007

The purpose of this study was to provide obese middle school girls with walking and behavior modification program(WBMP) by investigating effects of the exercise on their body composition(BC), physical fitness(PF) and metabolic syndrome(MS). Analysis result of the difference between before and after the exercise(paired and independent t-test) was acquired by measuring BC, PF and MS for 12 weeks(60min/day, three a week). 24 Volunteers were 14 years over ${\geq}223.64kg/m^2$ and 15 years over ${\geq}24.00kg/m^2$. In the body composition, waist circumference(WC), body fat mass(BFM), %fat, arm muscle circumference(AMC), total body water(TBW), physical score(PS) were significant difference between the exercise group(EG) and the control group(CG), also including all factors in PF. The components of metabolic syndrome were significant difference between EG and CG, but HDL-C, systolic & diastolic blood pressure were no difference. The metabolic syndrome factors by separate of waist girth were no difference between EG and CG, but BMI, diastolic blood pressure were significant difference. The prevalence of metabolic syndrome was 4 of 24(16.7%) before intervention, but it dropped from 2 to 1 after intervention in WBMP. The components of metabolic syndrome was distributed a big WC>low HDL-C>high TG>hypertension. The changes of AMC, We, PS, BW, 50m run and BFM effect the factors on BMI(35%), WHR(waist-hip ratio, 69%), HDL-C(42%), fasting blood glucose(65%), HOMA-IR index(34%) and systolic blood pressure(39%) respectively. There were significantly increased in breakfast frequency, walking steps, and meal eating period, but decreased in snacks and eating out in exercise group.

• Progress in Medical Physics
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• v.22 no.1
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• pp.28-34
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• 2011

To perform the Adaptive Radiation Therapy (ART), a high degree of deformable registration accuracy is essential. The purpose of this study is to identify whether the change of MV CBCT intensity can improve registration accuracy using predefined modification level and filtering process. To obtain modification level, the cheese phantom images was acquired from both kilovoltage CT (kV CT), megavoltage cone-beam CT (MV CBCT). From the cheese phantom images, the modification level of MV CBCT was defined from the relationship between Hounsfield Units (HUs) of kV CT and MV CBCT images. 'Gaussian smoothing filter' was added to reduce the noise of the MV CBCT images. The intensity of MV CBCT image was changed to the intensity of the kV CT image to make the two images have the same intensity range as if they were obtained from the same modality. The demon deformable registration which was efficient and easy to perform the deformable registration was applied. The deformable lung phantom which was intentionally created in the laboratory to imitate the changes of the breathing period was acquired from kV CT and MV CBCT. And then the deformable lung phantom images were applied to the proposed method. As a result of deformable image registration, the similarity of the correlation coefficient was used for a quantitative evaluation of the result was increased by 6.07% in the cheese phantom, and 18% in the deformable lung phantom. For the additional evaluation of the registration of the deformable lung phantom, the centric coordinates of the mark which was inserted into the inner part of the phantom were measured to calculate the vector difference. The vector differences from the result were 2.23, 1.39 mm with/without modification of intensity of MV CBCT images, respectively. In summary, our method has quantitatively improved the accuracy of deformable registration and could be a useful solution to improve the image registration accuracy. A further study was also suggested in this paper.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.1003-1009
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• 1996

Although esophagogastric (EG) anastomosis with a circular surgical stapler (EEA or ILS) is a safe find convenient proc dure with less anastomotic leakage, a concern for the anastomotic stricture still remains, especially in patients with small esophagus. We modified cervical EG anastomotic technique using straight thoracoscopic endostapler to prevent EG anastomotic stricture. Prospective clinical study was performed to determine the feasibility of our modification using Endo-GIA (US Surgical Corp., Worwalk), during the period from October, 1994 to July, 1995, in thirteen patients with carcinoma of the thoracic esophagus. A stomach tube was reanastomosed to the cervical esophagus utilizing a 30 mm Endo-GIA after esophagectomy and node dissection. There was one early mortality due to respiratory failure and pulmonary tuberculosis. Anastomotic leakage with resultant stricture was noticed in one patient, and it was re- lated to ischemic necrosis of the stomach tube. The overall incidence of stricture was 7.6 % (1113). During the 8 month follow-up period, the remaining 11 patients did not show any clinica evidence of stricture such as dysphagia. All patients were on a regular diet. We conclude that our new technique for cervical EG anastomosis with GIA-Endo stapler is a safe and convenient procedure in preventing anastomotic stricture.

• Journal of the Korean housing association
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• v.23 no.6
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• pp.49-59
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• 2012

This study suggested a new model in consideration of long life and constructability of apartment house suggested in the former part. New model suggested the possibility of cost saving based on the idea that people trend to reject because of the recognition that the new model would cost a lot of expense which work as the barrier for the expansion and distribution at the local market so as to prepare the ground for its activation. The Study was aimed at verifying the possibility of cost saving through comparing it with the existing standard apartment house system centered on the skeleton and cladding system among the new structural design models suggested in the former part. Assuming that these existing standard both models should be changed structural design into new model system, the quantity volume, cost and construction period along with the alteration of finished materials between two models were compared altogether. Simultaneously BIM library was built for easy taking-off bill of quantity and consideration of working methodology for construction working cycle, which was translated into construction cost so as to derive the cost of the two subject systems to be counted. Through the analysis, it was concluded that new model would secure variability in the future and constructability along with shortening the construction period (29%) and achieve cost saving (13%) of construction against the those of existing model.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.31-39
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• 2002

A rapid growth of internet and sudden increase of multimedia data demands for high-speed transfer media and if optimizec usage from the interface system. To achieve this level of network bandwidth, multiple NICs for support of high-speed network bandwidth have been developed and studied. Furthermore, the use of multiple NICs can provide high-speed LAN environment without large network environment modification, supports backward compatibility of current system and reduce overhead. However. if system failure is caused by SPOF(Single Point of Failure) fault of large-capacity multiple NICs, incredible loss will be met because it services large capacity of multimedia data, Therefore, to prevent loss coming from faults, we describe 'Fault tolerance of multiple NICs', which use the fault prevention mechanism. Considering inefficiency of availability and serviceability that is occurred with existing TMR, Primary-Standby approach and Watchdog time mechanism, we propose and design the efficient fault tolerance mechanism, which minimize down time as changing of detection period dynamically. Consequently, the fault tolerance mechanism proposed for reducing overhead time when the fault is occurred, should minimize system downtime overall.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.112-116
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• 2005

We investigated the surface modification method for the preparation of organic-inorganic hybrid composite thin film. Gelatin obtained from the decomposition of collagen was allowed to adsorb in a polystyrene tissue culture dish for 2 h to from layers of gelatin. Supersaturated ionic solution of calcium and phosphorus was injected on the gelatin adsorbed layer to form calcium phosphate thin film. During the initial period of incubation, nucleates were formed. With increase of the incubation time, CaP (calcium phosphate) thin film grew on the surface of the culture dish. The gelatin/CaP thin film displayed the highly porous three-dimensional surface structure. Attenuated, total reflectance Fourier transform, infra-red spectroscopy (ATR-FTIR) was used to analyze the chemical properties of CaP film. The analysis demonstrated that the CaP film formed at initial period of treatment appeared to be amorphous. With increase of incubation time, the crystallinity of the film was slightly increased, but the presence of the peaks for the low crystalline CaP confirmed that the CaP thin film prepared in this study was poorly crystallized.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.255-260
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• 2014

A new sustain driving waveform and its implementation method is proposed to improve the gray scale linearity by applying the sustain waveform for producing the strong and weak discharge in AC plasma display panel. The driving method to express the gray scale of AC PDP is the combination of the several subfield in one TV frame, and the luminance of the each subfield is decided by the number of the sustain pulses. As the same amount of the strong plasma discharge is produced when the sustain pulses are applied during a sustain period, it looks easy to express the linear gray scale ideally. However, it is difficult to express the real linear gray scale due to the production of the address and first sustain discharge irrelevant to gray scale expression in every subfleld. Therefore, a new sustain driving waveformis adopted to produce partially the weak discharge instead of the strong discharge by the modification of the sustain pulses shape during the sustain period and the gray scale expression is close to the linearity.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.24 no.1
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• pp.25-44
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• 2013

The purpose of this study was to analyze the trends of Classification Studies in Korea from 205 research articles in five scholarly journals in Library and Information Science during the period 1986-2011. Individual article was analyzed in the aspects of specific research topics, research methodologies, data collection & analysis, and the characteristics of classification research was suggested. The amount of research paper has increased during the period and the focus of the study was on practical use and most of the papers were about new classification schedules or modification of current classification systems. Most of the papers were literature research and comparative research on classification systems by professors or graduate students. Top 9 authors in classification research were professors or lecturers and a few authors were computer science major. Therefore, various research topics, research methodologies and collaborations with other disciplines are necessary for future classification research.