• Earthquakes and Structures
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• 제26권2호
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• pp.131-147
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• 2024

Damage caused by an earthquake depends on not just the intensity of an earthquake but also the region-specific construction practices. Past earthquakes in Asian countries have highlighted inadequate construction practices, which caused huge life and property losses, indicating the severe need to strengthen existing structures. Strengthening activities shall be proposed as per the proposed weighting factors, first at the higher weighted members to increase the capacity of the building immediately and thereafter, the other members. Through this study on gravity load-designed (GLD) buildings, relative weights are assigned to each storey and exterior and interior columns within a storey based on their contribution to the energy dissipation capacity of the building. The numerical study is conducted on mid-rise archetype GLD buildings, i.e., 4, 6, 8, and 10 stories with variable storey heights, in the high seismic zones. Non-linear static analysis is performed to compute weights based on energy dissipation capacities. The results obtained are verified with the non-linear time history analysis of 4 GLD buildings. It was observed that exterior columns have higher weightage in the energy dissipation capacity of the building than interior columns up to a certain building height. The damage in stories is distributed in a convex to concave parabolic shape from bottom to top as building height increases, and the maxima location of the parabola shifts from bottom to middle stories. Relative weighting factors are assigned as per the damage contribution. And the sequence for strengthening activities is proposed as per the computed weighting factors in descending order for regular RCC buildings. Therefore, proposals made in the study would increase the efficacy of strengthening activities.

• KSBB Journal
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• 제26권5호
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• pp.439-442
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• 2011

1,2-propanediol (1,2-PD) is a commodity chemical that is currently produced from petrochemical derivatives. Saccharomyces cerevisiae is well characterized and a successful industrial microorganism to enable the improvement of the 1,2-propanediol production by metabolic engineering. A recombinant S. cerevisiae M3G3 was used to produce 1,2-propanediol. S. cerevisiae M3G3 is the diploid strain that contains 3 copies of mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase). S. cerevisiae M3G3 was cultivated at various culture conditions by changing culture temperature, glucose concentration, and inducer concentration. Also the effect of induction time was studied to optimize the production of 1,2-propanediol. Batch and fed-batch cultivation of S. cerevisiae M3G3 was performed by using a 5 L jar fermenter. The highest concentration of 1,2-propanediol in batch cultivation was 0.86 g/L and it was further improved to 1.33 g/L in fed-batch cultivation.

• 당뇨병
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• 제19권3호
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• pp.135-139
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• 2018

The sodium-glucose cotransporter-2 inhibitor (SGLT2i) is a new anti-hyperglycemic agent that have function to concomitantly inhibit the reabsorption of glucose and sodium in the renal proximal convoluting tubule. Recent two cardiovascular outcome trials showed that a lower risk of cardiovascular events with SGLT2i in people with type 2 diabetes. In addition, prior real-world data demonstrated similar SGLT2i effects, but these studies were limited to the United States and Europe. Thus, the CVD-REAL (Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors) 2 Study was investigated cardiovascular outcomes in those initiated on SGLT2i versus other glucose-lowering drugs (oGLDs) across 6 countries in the Asia Pacific, the Middle East, and North American regions. In Korea, 336,644 episodes of initiation in SGLT2i or oGLD group between September 2014 and December 2016 were identified in Korea National Health Insurance database after propensity score matching. SGLT2i users was associated with a lower risk of all-cause death (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.67~0.77), hospitalization for heart failure (HHF) (HR, 0.87; 95% CI, 0.82~0.92), all-cause death or HHF (HR, 0.81; 95% CI, 0.78~0.85), myocardial infarction (HR, 0.81; 95% CI, 0.74~0.89), and stroke (HR, 0.82; 95% CI, 0.78~0.86) compared with oGLD users. In conclusion, initiation of SGLT2i had a lower risk of cardiovascular events in people with type 2 diabetes compared with oGLDs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권8호
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• pp.1894-1912
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• 2012

This paper proposes a system called Wireless Link based on Global Communication Channel (WLGCC) to enhance the spectrum sharing between digital broadcasting (DB) services and the cognitive radio (CR) system in the licensed band of 470-790 MHz. The WLGCC aims to enhance the spectrum sensing and geolocation database (GLD) spectrum sharing methods in the CR system. Spectrum sensing can be enhanced by receiving the status of the used frequencies from the WLGCC, thereby eliminating the need for a low detection threshold (i.e., avoiding the hidden node problem). In addition, the GLD can be enhanced by providing a reliable communication link between the database and the CR device in the form of an unused TV white space that is reserved as the proposed Global Communication Channel (GCC). This paper analyzes the coexistence of the new WLGCC system and the DB service in terms of avoiding additional interference. Specifically, we mathematically determine the WLGCC parameters, such as the in-band and out-of-band power levels, and operation coverage, and verify them using Monte Carlo simulation. The results show that WLGCC does not degrade the existing DB service and reliably transmits information of the vacant (or used) frequency bands to the CR.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.328-332
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• 2011

The conclusion is derived from the arranged results and using a simulation by determining the shape of an optimum heat pump which is appropriate for small scale houses. It is concluded as 3 meters long for the laying depth of underground piping of the horizontal type geothermal heat pump system in regard to the 5 RT capacity standard that is suitable for a small scale house. The shape of the horizontal type geothermal heat pump system for a small scale house is theThree pipe shape whose trench length is short and pipe length laid in a trench is short. It is 9 for the number of laying pipes that is most appropriate to system.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1439-1444
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• 2008

The recombinant E. coli $\Delta$6 mutant (galR, glpK, gldA, IdhA, lacI, tpiA) was used to produce 1,3-propanediol (PD) from glucose. The 1,3-PD production increased with feedback control of the glucose concentration using fed-batch fermentation. The maximum 1,3-PD concentration produced was 43 g/l after 60 h of fermentation. Glycerol production was minimized when controlling the glucose concentration at less than 1 g/l. The expression levels of seven enzymes related to the 1,3-PD production metabolism were compared during the cell growth phase and 1,3-PD production phase, and their expression levels all increased during 1,3-PD production, with the exception of alcohol dehydrogenase.

• Communications for Statistical Applications and Methods
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• 제29권3호
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• pp.301-317
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• 2022

In this paper, we propose a change point detection procedure based on the modified information criterion in a generalized lambda distribution (GLD) model. Simulations are conducted to obtain empirical critical values of the proposed test statistic. We have also conducted simulations to evaluate the performance of the proposed methods comparing to the log-likelihood method in terms of power, coverage probability, and confidence sets. Our results indicate that, under various conditions, the proposed method modified information criterion (MIC) approach shows good finite sample properties. Furthermore, we propose a new goodness-of-fit testing procedure based on the energy distance to evaluate the asymptotic null distribution of our test statistic. Two real data applications are provided to illustrate the use of the proposed method.

• 한국지열·수열에너지학회논문집
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• 제9권4호
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• pp.9-14
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• 2013

A ground loop heat exchanger for the ground source heat pump system is the important equipment determining the thermal performance and initial cost of the system. The length and performance of the underground heat exchanger is dependent on ground thermal conductivity, operation hours, ground loop diameter, grout, ground loop arrangement, pipe placement and design temperature. In this study we find out heat exchanger length with various design factor.

• 한국ITS학회 논문지
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• 제10권6호
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• pp.108-117
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• 2011

서울시는 2001년부터 실시간 신호제어시스템(COSMOS)를 운영하고 있으며, 도시부 신호교차로의 신호운영 자료인 포화도 및 대기길이의 산출을 위하여 검지기를 설치해 차량으로부터 기초자료를 습득하고 있다. 현재 가장 보편적으로 사용하는 것은 유도성 루프검지기로 도로의 노면에 매설하는 방식이라 유지 보수가 용이하지 않고 비용이 많이 드는 단점이 있다. 또한 대기길이의 산정시 검지기를 통과하는 차량의 속도만으로 계산해야하기 때문에 속도측정 오차 발생시에 대기길이의 값에 영향을 미치게 된다. 제안하는 알고리즘은 카메라, 센서 및 이미지처리 장치와 같은 추가적인 장치 없이, VANETs(Vehicular Ad-hoc Networks)의 차량 간의 통신을 이용하고 각 방향별 그룹을 설정하여 교차로에서 원활한 교통 흐름을 가능케 하는 실시간 교통신호 제어 시스템을 제안한다. 본 연구에서 제안한 알고리즘은 GLD(Green Light District) Simulator를 기반으로 단일교차로 모델에서 AJWT(Average Junction Waiting Time)와 TQL(Total Queue Length) 에 대해서 확인하였으며 그 결과를 무작위(Random) 제어방식 및 최상우선(Best first) 제어방식과 비교하여 더 나은 결과를 보였다. 향후 VANETs를 활용한 실시간 제어방법이 보편화 될 경우 무선 통신기술을 이용한 교차로의 교통제어기술을 제안한 본 연구는 그 활용가치가 높을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1346-1351
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• 2018

Oxidoreductases are effective biocatalysts, but their practical use is limited by the need for large quantities of NAD(P)H. In this study, a whole-cell biocatalyst for NAD(P)H cofactor regeneration was developed using the economical substrate glycerol. This cofactor regeneration system employs permeabilized Escherichia coli cells in which the glpD and gldA genes were deleted and the gpsA gene, which encodes $NAD(P)^+-dependent$ glycerol-3-phosphate dehydrogenase, was overexpressed. These manipulations were applied to block a side reaction (i.e., the conversion of glycerol to dihydroxyacetone) and to switch the glpD-encoding enzyme reaction to a gpsA-encoding enzyme reaction that generates both NADH and NADPH. We demonstrated the performance of the cofactor regeneration system using a lactate dehydrogenase reaction as a coupling reaction model. The developed biocatalyst involves an economical substrate, bifunctional regeneration of NAD(P)H, and simple reaction conditions as well as a stable environment for enzymes, and is thus applicable to a variety of oxidoreductase reactions requiring NAD(P)H regeneration.