• Computational Structural Engineering
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• v.8 no.3
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• pp.103-111
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• 1995

Evaluating nonlinear response of a MDOF system under dynamic stochastic loads such as seismic excitation usually requires excessive computational efforts. To alleviate this computational difficulty, an approximation is developed in which the MDOF inelastic system is replaced by a simple nonlinear equivalent system(ENS).Me ENS retains the most important properties of the original system such as dynamic characteristics of the first two modes and the global yielding behavior of the MDOF system. The system response is described by the maximum global(building) and local(interstory) drifts. The equivalency is achieved by two response scaling factors, a global response scaling factor R/sub G/, and a local response scaling factor R/sub L/, applied to the responses of the ENS to match those of the original MDOF system. These response scaling factors are obtained as functions of ductility and mass participation factors of the first two modes of structures by extensive regression analyses based on results of responses of the MDOF system and the ENS to actual ground accelerations recorded in past earthquakes. To develop the ENS with two response scaling factors, Special Moment Resisting Steel Frames are considered. Then, these response scaling factors are applied to the response of ENS to obtain the nonlinear response of MDOF system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.63-74
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• 2000

The main objective of this paper is to apply as the basic data for development of a methodology to discuss the future earthquake preparedness measures in Korea by investigating the concept and applicabilities of the Japanese Standard for Evaluation of Seismic Performance of Existing RC Buildings developed in Japan among the methodologies of all the countries of the world. This paper describes the seismic performance, Is-index, of existing RC buildings in Tokyo, Japan evaluated by the Japanese Standard, also the relationships between Is-index distribution of existing RC buildings in Tokyo and that of Shizuoka and Chiba Prefecture reported already in reference[4][5][6] are investigated. And from the comparison with Is-index to buildings damaged by earthquakes experienced in Japan, the damage ratio due to severe earthquake of 3 districts mentioned above is estimated based on the probabilistic point of view. The results of this study can be utilized to identify urgently required earthquake preparedness measures with highest priority in existing RC buildings, and the methodology to evaluate the seismic performance of existing RC buildings in Japan, statistics analysis method and the methodology to estimate earthquake damage ratio based on the probabilistic point of view shown in this study can be recommended to develop a methodology to discuss the future earthquake preparedness measures in Korea.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.337-364
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• 2005

The vascular flora of Mt. Deokhang (a.s.l. 1072.5m, $37^{\circ}17^{\prime}{\sim}37^{\circ}20^{\prime}N$, $128^{\circ}09^{\prime}{\sim}129^{\circ}03^{\prime}E$), one of the limestone areas in Korea and is located between Samcheok-si and Taebaek-si, Gangwon-do, is surveyed from 10 Oct. 2003 to 4 Oct. 2005. The characteristics of the flora from the phytogeographical point of view is also discussed. The number of the vascular plant taxa identified in this study is 590 in total which belongs to 90 families, 337 genera, 537 species, 4 subspecies, 46 varieties and 3 forms. Of them, 30 taxa are endemic to Korea, 4 taxa are legally protected ones, and 17 taxa are generally regarded as rare and endangered species in Korea. Naturalized plants are 19 taxa. The phytogeographical importance and the conservation strategy of the flora of Mt. Deokhang focusing on either rare, endemic or phytogeographically important species are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.751-760
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• 2018

Currently, the quality measurement of the work is carried out by the supervisor's visual inspection, as the workers individually judge the number of resolutions, thickness, speed and vibration. After work, we are conducting follow-up work through traditional spot test, which is less representative. Therefore, it is impossible to check the results of the resolution, and there is always the possibility that problems will arise due to poor construction. This study demonstrates the feasibility of using the continuous compaction strength measurement method by comparing the continuous compaction strength measurement method and the conventional compaction strength measurement method after performing the compaction in the actual field scale in various test conditions. The validity is verified by analyzing the Compaction Meter Value of an Intelligent Compaction roller composed of a Global Positioning System and an accelerometer, Based on the proven results, a full range of quality can be confirmed without a single test. The quality confirmation is visualized in the compaction control program developed in this study, This enables the field manager to perform real-time quality monitoring at the same time as compaction.

• Journal of Korean Academy of Nursing
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• v.50 no.4
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• pp.571-582
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• 2020

Purpose: This study aimed to determine the effects of a 12-week metabolic syndrome BeHaS (Be Happy and Strong) program in elderly people with metabolic syndrome living alone, based on a community-based participatory research (CBPR). Methods: A nonequivalent control group pre-posttest design was used, and the participants were 43 elderly people living alone (experimental group 24, control group 19). The experimental group received a one-hour program per week and two individual health consultations during 12 weeks. The control group received two sessions about the metabolic syndrome and two individual health consultations. The effects of health behavior, blood pressure, blood sugar levels, abdominal circumference, triglycerides, and self-esteem were evaluated. The data were analyzed using the independent t-test and Mann-Whitney U test. Results: The health behavior with respect to the metabolic syndrome in the experimental group increased significantly (t = - 3.19, p = .002). Both diastolic blood pressure and abdominal circumference decreased in the experimental group (t = 2.00, p = .028 and t = 3.91, p < .001). No significant differences were observed between the groups in systolic blood pressure, fasting blood sugar levels, triglycerides, and self-esteem. Conclusion: The 12-week metabolic syndrome BeHaS program using community resources improves the health of elderly people with metabolic syndrome living alone. Based on these findings, further studies on the effectiveness of the metabolic syndrome BeHaS program and the experiences of those who participated in the CBPR are warranted.

• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.129-139
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• 2004

Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.333-340
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• 2010

This paper presents the distributions of the tensile and fracture properties of an alloy 82/182 dissimilar weld joint between an SA508 Gr.3 nozzle and F316L SS safe-end at ambient temperature. Tensile and J-R tests were conducted using specimens extracted from base metals, heat-affected zones (HAZs), buttering regions, and various regions of the weld metal. The results show that the root region of the weld has higher strength than the upper region. The yield and tensile strengths vary considerably within the root region of the weld. The buttering region had the lowest strengths. The strengths gradually increased as the F316L stainless steel weld boundary was approached. The variation of the strengths within the upper region of the weld is insignificant. The fracture toughness of the alloy 82/182 weld metal is less than those of both the base metals and both HAZs. Within the alloy 82/182 weld, the center of weld has a slightly lower fracture toughness than the weld boundary and buttering region, and the root region has greater toughness than the upper region of the weld.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.408-415
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• 1993

Studies on seasonal prevalence and geographical distribution of chigger mites were carried out during the period of August 1990-December 1991, and the results are summarized as follows. From total 325 field rodents collected during the study period, 15,679 chiggers were obtained and 12 species of 4 genera were identified. Leptotrombidium pallidum, a vector species of tsutsugamushi disease in Korea was the predominant species and distributed throughout the country except southern part of Korea, whereas L. scutellare, known also as a vector species was distributed mainly in southern part of Korea. The distribution of chigger mites was strongly localized by species, showing different predominant species at each locality during the same season. The predominant species were L. pallidum(92.3%) at Dorai-5ri, Wondang-ub, Neotrombicula kwangneungensis (44.7%) at Sanjung-ri, Pochun-gun, N. tamiyai (55.1%) at Changgok-ri, Paju-gun, L. orientale (55.2%) at Jangsin-ri, Iksan-gun, and L. scutellare (47.6%) at Sinyong-dong, Iri-si. Study on seasonal prevalence of L. pallidum chiggers resulted that they started appearing in September, showed the peak in November, almost disappeared during the period of December-March, reappeared in April-May showing a small peak, and again almost disappeared until September. L. scutellare showed the peak in October, sharply decreased thereafter, and disappeared during the period of January-September.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.200-206
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• 1982

A computer simulation model was constructed to explore the phonology of the Striped Rice Borer, Chilo suppressalis (Walker), in Korea. The phenological system model based on the concept of distributed time delay was written in the computer program 'INSECT' and simulated with the estimated parameters of the effective day-degrees (DEL) and the order of time delay (K) for determining the validity of the system model. The accumulated emergence curves obtained from the phenological model were slightly different from the observed light trap data at the early and late stage of the moth emergence in 1978. The differences between observed and simulated $50\%$ emergence date were five to six days in the locations of Suweon and Chuncheon, while it was only two to three days in Iri, Daegu, Boseong, and Milyang. The phenological model should be further improved for simulation of field population changes by adding the information of the time delay process in each developmental stage, the age distribution of overwintered population, and the limiting factors of the borer mortality.

• Journal of the Korean Chemical Society
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• v.39 no.11
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• pp.869-877
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• 1995

Carbonation process of Jung sun slake lime$(Sr(OH)_2=0.053 wt%)$ suspension with $CO_2$ gas at 30∼80$^{\circ}C$ has been studied to investigate the formation process of aragonite. The reaction temperature at above $50^{\circ}C$, rhombic nuclei of $SrCO_3$ has been grown with the interaction of $CO_3^{2-}$(aq) which is profitable to growth the nuclei at the liquid film of gas-liquid interface to form pillar aragonite crystal. At $40^{\circ}C$, the controlling of concentration of $CO_2$(aq) at the beginning of the reaction has been made the nuclei to growth to be an aragonite crystal. Addition of some $Sr(OH)_2$ to Yi Lee slake lime $(Sr(OH)_2=0.011 wt%)$ suspension and controlling the concentration of $OH^-$(aq) and $CO_2$(aq), the carbonation reaction produced pillar aragonite crystal with the short side of 0.1∼0.2 ${\mu}m$ and long side of 1∼2 ${\mu}m.$