파형 복부판이 수평 곡선 I형 거더의 극한 거동에 미치는 영향

김승준,한택희,원덕희,강영종,Kim, Seungjun,Han, Taek Hee,Won, Deok Hee,Kang, Young Jong 대한토목학회 2013 대한토목학회논문집 Vol.33 No.4

본 논문은 파형 복부판이 수평 곡선 I형 거더의 극한 거동에 미치는 영향을 다룬다. 파형 복부판은 기하학적 특성에 따라 플레이트 거더의 비틂 및 뒴 강성 증진을 위해 적용이 가능하다. 그동안 파형 복부판이 일반 직선 거더의 극한 거동에 미치는 영향을 다룬 많은 연구들이 있었으나, 면외 방향 거동이 주요하게 나타나는 곡선 거더의 극한 거동에 미치는 영향에 대한 연구는 거의 이루어지지 않았다. 이 연구에서는 비탄성-비선형 해석을 통해 파형 복부판 수평 곡선 I형 거더의 극한 거동을 다룬다. 본 해석 연구에서는 파형 복부판을 갖는 곡선 거더의 극한 거동에 영향을 미칠 수 있는 기하학적 인자로써, 곡선 거더의 횡방향 비지지 길이와 사잇각, 복부판의 파고 및 파장이 주요 매개변수로 고려되었다. 본 해석 연구를 통해, 각 매개변수 변화에 따른 극한 거동 및 내하력 변화를 분석하고, 일반 판형 복부판이 적용된 거더의 내하력과 비교하여 파형 복부판이 내하력 증진에 미치는 영향을 도출하였다. 본 해석 결과에 따르면, 높은 비틂 및 뒴 강성에 의해 파형 복부판은 곡선 거더의 내하력 증진에 효과적인 것으로 나타났다. 그러나 곡선 거더의 곡률 또는 사잇각이 작은 경우, 파형 판의 아코디언 효과에 의해 오히려 내하력이 감소될 수 있다는 것 또한 나타났다. In this study, the effects of corrugated webs on the ultimate behavior of horizontally curved I-shaped girders are investigated. Because of the geometric characteristics of corrugated plates, corrugated webs can be used for enhancing torsional and warping stiffness of plate girders. Many researches have been conducted to study the effects of corrugated webs on the ultimate behavior of straight girders. But, the studies of the ultimate behavior of horizontally curved girders with corrugated webs, which generally show out-of plane behavior manly, have been rarely performed so far. By performing inelastic-nonlinear analysis, the ultimate behavior of curved girders with corrugated webs is studied in this paper. Laterally unsupported length and subtended angle of girders, and length of height of corrugation of webs are considered as the geometric parameters which would be expected to affect the ultimate behavior. By this analytical study with considering the geometric parameters, the changes of ultimate behavior and load carrying capacity of curved girders with corrugated webs are investigated. Also, the effects of corrugated webs on the increase of load carrying capacity for curved girders are studied with comparing to the capacity of general curved girders with flat webs. According to the analytical results, corrugated webs can be used to increase the ultimate load carrying capacity of curved girders, because of their high torsional and warping stiffness. But, it is also indicated that they may decrease the load carrying capacity of curved girders which have relatively small subtended angle or initial curvature, because of an accordion effect.

Effects of Priming Progesterone on the LH Surge Expressions in Ovariectomized Shiba Goats

김승준 한국임상수의학회 2014 한국임상수의학회지 Vol.31 No.1

This study tested the hypothesis that the priming effects of progesterone on the timing of the LH surgeinduced by exogenous estradiol are more potentiated the negative feedback actions of progesterone on LH secretionby the existence of estradiol. In previous studies, the time interval from estradiol infusion until the peak of LH surgewas gradually and significantly extended by the different levels of progesterone treated before estradiol infusions. Longtermovariectomized Shiba goats that had received implants of estradiol capsules (Day 0) and three different progesteronesilastic packet inducing follicular, subluteal and luteal levels of progesterone were divided into three groups such asnon-P, low-P and high-P group. Blood samples were collected daily throughout the experiment for the analysis ofgonadal steroid hormone levels. On Day 7, all devices of progesterone and estradiol packets were removed but estradiolcapsules were maintained during the experiment, and blood samples were collected at 1 hr interval for 12 h from thetime of progesterone removals to determine peripheral changes of estradiol and progesterone concentration. Then allanimals were infused estradiol on the Day 7 after 13 h from the removals of progesterone devices with a peristalticpump into jugular vein at a rate of 3-6 μg/h for 36 h. For analysis of peripheral LH and estradiol concentration, bloodsamples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before the start of estradiol infusionto 48 h after the start of estradiol infusion). In all animals of the three groups treated with estradiol infusion, an LHsurge was expressed but the peak time of LH surge was different. This time interval was not extended by the differentlevels of progesterone treated before estradiol infusions and the difference was not significant during this intervalbetween the Low P and the High P groups. Progesterone pretreatment may contribute to regulating the neural systemthat is responded by estradiol, and estradiol existence potentiates the negative feedback effect of progesterone on GnRH/LH surge-generating system.

서울시 지하철의 혼잡비용 산정과 정책적 활용방안

김승준 서울연구원 2016 정책리포트 Vol.- No.208

UV lamp를 사용한 피부 접촉용 지류 살균기 개발

김승준,최지성,양원균,주정훈 한국표면공학회 2009 한국표면공학회 학술발표회 초록집 Vol.2009 No.-

자외선 램프를 이용한 살균기는 고전압 방전과 달리 오존의 발생을 최소화 하면서 짧은 시간에 원하는 물체를 살균할 수 있는 장점이 있다. 본 연구에서는 인체의 피부에 직접 접촉하는 티슈들의 포장 상태에서 세균의 밀도를 조사하고 그 결과 살균이 필요한 수준이라는 것을 파악한 다음, 공중 화장실용 공동 티슈 공급기에 적합한 살균기를 설계, 제작하고 그 효과를 세균 배양 실험을 통하여 확인하였다.

Emergences of LH Surge Affected by Different Progesterone Levels in Ovariectomized Goats

김승준 한국임상수의학회 2014 한국임상수의학회지 Vol.31 No.1

The purpose of the present study was to determine the priming effects of progesterone that affect theemergence of LH surge mode secretion by three different progesterone levels. In previous studies, we have shownthat LH surge occurred in follicular levels of progesterone, whereas there was no surge mode secretion of LH andFSH in either the subluteal or luteal levels of progesterone. In this study, the hypothesis was that the priming effectsof progesterone on the timing of the LH surge induced by exogenous estradiol are same between subluteal and luteallevels of progesterone. Long-term ovariectomized Shiba goats that had received implants of estradiol capsules (Day0) and three different progesterone silastic packet inducing follicular, subluteal and luteal levels of progesterone weredivided into three groups such as non-P, low-P and high-P group. Blood samples were collected daily throughout theexperiment for the analysis of gonadal steroid hormone levels. On Day 7, all devices of progesterone packets wereremoved but estradiol capsules were maintained during the experiment, and blood samples were collected at 1 hr intervalfor 12 h from the time of progesterone removals to determine peripheral changes of estradiol and progesteroneconcentration. Then all animals were infused estradiol on the Day 7 after 13 h from the removals of progesteronedevices with a peristaltic pump into jugular vein at a rate of 3 μg/h for 36 h. For analysis of peripheral LH and estradiolconcentration, blood samples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before thestart of estradiol infusion to 48 h after the start of estradiol infusion). In all animals of the three groups treated withestradiol infusion, an LH surge was expressed but the peak time of LH surge was different. This time interval fromestradiol infusion until the peak of LH surge was gradually and significantly extended by the different levels ofprogesterone treated before estradiol infusions in the three groups.

혈소판 농축액이 이식된 지방의 생존에 미치는 영향

김승준,최원일,이병일,박승하,박철,구상환 대한성형외과학회 2007 Archives of Plastic Surgery Vol.34 No.3

Purpose: Platelet-rich plasma(PRP) contains protein growth factors, which are actively secreted by platelets to promote wound healing. However, it is not clear whether the injection of PRP into the autologous fat grafts increases the survival rate and the degree of angiogenesis.Methods: New Zealand White rabbit ears were injected fat with PRP, saline, insulin or isoproterenol (n=8/each group) for observation of the survival and degree of angiogenesis of the injected fat. The volume of the harvested fat and the degree of angiogenesis from dorsum of rabbit ears were evaluated 4, 8, and 12 weeks after the autologous fat graft. The degree of angiogenesis was measured with microvascular density (MVD) counts.Results: The volume of harvested fat decreased in a time-dependent manner after autologous fat grafts, but the decrease rate in volume of harvested fat was slower in PRP-injected group compared to that of other control groups. The difference in the volume of the harvested fat between PRP-injected group and other control groups became significant from 4 weeks after the autologous fat graft, and was maintained up to 12 weeks. However, there was no significant difference between PRP-injected group and insulin-injected group 8 and 12 weeks after the autologous fat graft. On the contrary, MVD counts increased in a time-dependent manner after autologous fat grafts. The MVD counts were significantly higher in PRP-and insulin-injected groups than in other control groups from 4 weeks after the autologous fat graft, and these differences were maintained up to 12 weeks. There was no correlation between mean platelet numbers and the volume of harvested fat.Conclusion: The present study demonstrates that PRP-injection into autologous fat grafts increases the survival rate and the degree of angiogenesis. Thus, PRP injection with autologous fat grafts would be a promising tool for maintaining the volume of the grafted fat.

Structural Stability of Cable-stayed Bridges

김승준,원덕희,이기세,강영종 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.3

This paper presents an investigation of the structural stability of cable-stayed bridges based on nonlinear analysis. In general, girders and masts of cable-stayed bridges are always subjected to compressive forces due to pre-tensioned stay cables. Cablestayed bridges exhibit various geometric nonlinearities, such as the cable-sag effect, beam-column effect of girders and masts, and large displacement effect. In this study, the characteristics of the structural stability of cable-stayed bridges are investigated. Because of various geometric nonlinearities, nonlinear finite element analysis should be performed for stability analysis instead of conventional eigenvalue analysis. Furthermore, the initial shape analysis should be performed prior to live load analysis in order to consider the dead load condition rationally. A two-step analysis method, developed based on the theory of nonlinear finite element method, is presented in this study for stability analysis under live load cases. An intensive series of parametric studies is subsequently performed using three-span cable-stayed bridges. The main buckling modes are classified depending on the location of the critical members. Also, the effects of cable arrangement, girder-mast stiffness ratio, area, and the number of cables on the structural stability are extensively investigated.

후드형 BLDC 헤어드라이기 디자인 개발 사례 연구

김승준,정석길 한국인더스트리얼디자인학회 2016 산업디자인학연구 Vol.10 No.2

This study is focused on the application of the BLDC motor in the Hood type BLDC hairdryer produced by H electronics. We have researched the current domestic and international market environment and overall conditions to deduce possible problems and develop a differentiated product concept to tackle said problems. We have concluded to a specific design output by going through all the design processes such as; Gathering data by market analysis of the products from competitors, previous company products and other on/offline related data, Forming a strategy for designing a new product to match the data, Developing a concept, Idea sketches, Renderings, and 3D simulations. Although the traditional design process have be mainly used, additional research and analysis have been conducted to incorporate any specific methods of use by the users. Analysis has brought out that hair designers use the hairdryers in a variety of ways, so to integrate these methods of use, human centric research of the position, angle, and material of the handle were conducted to meet these design needs. We gained the confidence of the relevant departments throughout the many stages of development, and by using the finished mockups, we were able to communicate with the many departments to develop a more complete and adequate design. Through the use of the finalized design, the company was able to secure a competitive position in the Red Ocean market and with the competitive design the company participated in multiple exhibitions and fixed a secure platform to dive into international markets. 본 연구는 BLDC모터 적용 기술과 그 연구의 대상 범위를 좁게 정하여 실체적으로 적용시켜보고자 헤어드라이기 전문업체인 H 전자의 유럽향 후드형 BLDC 헤어드라이기를 연구 대상으로 선정하였다. 현재 국내·외 헤어드라이기 시장의 현황 그리고 국내·외 시장 환경 등 제반 여건을 전반적으로 조사하여 문제점을 도출하고 이를 토대로 효율적이고 차별화된 제품 콘셉트를 개발하고자 하였다. 경쟁사 제품분석을 기초로 한 시장분석과 기존 제품 데이터 및 온·오프라인 상의 관련 데이터를 수집, 분석하여 신제품의 디자인 전략 수립, 디자인 콘셉트 개발, 아이디어 스케치, 렌더링, 3D 설계 시뮬레이션 등에 걸친 전 단계 디자인 프로세스를 거쳐 구체적인 결과물을 도출하였다. 일반적인 디자인 프로세스를 중심으로 진행하되 사용자의 특성을 고려하여 여러 가지 사용법들에 대한 분석과 연구도 병행하여 실시한다. 일반 적으로 헤어 디자이너들은 다양한 방법으로 헤어드라이기를 사용하는 것으로 분석되었는데 이를 바탕으로 하여 인간 공학적인 접근으로 손잡이의 위치 및 각도와 재질적인 측면이 다각적으로 고려된 디자인이 필요하므로 그에 대응하는 제품디자인의 연구를 진행하였다. 각 개발 단계별로 해당부서와 신뢰를 쌓고 완성된 목업을 바탕으로 여러 부서와의 소통을 통하여 디자인의 완성도를 높여 개발하였다. 완성된 디자인의 결과로서, 현재 ‘레드오션(Red Ocean)’인 해당 시장에 공격적으로 대응할 수 있는 디자인 경쟁력을 확보할 수 있게 되었고 디자인 경쟁력을 갖춘 제품으로 각종 전시회에 참여함으로서 해외수출시장에 대한 명확한 시장 경쟁력을 확보하게 되었다.

효과적인 잡음 제거와 가속도 계측을 통한 구조적 변위 추정 연구

김승준,임석빈,최준호,강영종 한국방재학회 2012 한국방재학회논문집 Vol.12 No.5

In this study, the estimation method for the structural displacements by the acceleration measurement is investigated for effective real-time structural monitoring. Theoretically, the velocity and displacement data during the specific period can be obtained by integration of the measured acceleration. But, the integrated data is highly affected by unexpected error sources such as noise signal. So, the effective and rational method for the noise elimination or minimization should be suggested and used. In this study, an effective noise filtering method for an useful displacement estimation by double integration is suggested based on the characteristics of structural dynamics. For the rational noise filtering technique applied to the measured acceleration data, the multi bandpass filter, which allows the signals nearby the peak frequencies of measured data, is newly suggested. By the suggested filtering and double integration method, the estimation method of structural displacements using an acceleration measurement is suggested in this study. The accuracy and rationality of the suggested method was validated using the numerical example obtained by finite element analysis. In the validation, the displacement data estimated by the suggested method was directly compared with those obtained by highpass filter and bandpass filter, formerly well known methods. 본 연구는 효과적인 실시간 구조 모니터링을 위한 가속도 계측을 통한 구조적 변위의 추정기법에 대해 다룬다. 이론적으로가속도를 적분하면 계측 시간 동안의 변화된 속도와 변위 데이터를 얻을 수 있지만 이중 적분을 수행하여 변위를 얻어낼 때계측신호의 잡음의 효과가 매우 크게 나타나는 단점이 존재한다. 따라서 이러한 오차요인을 효과적으로 제거할 수 있는 방법이제시되어야 가속도 계측 기반 변위 추정 기술이 보다 실용성 있게 된다. 본 연구에서는 구조물의 동적 거동 특성을 반영한 효과적인 가속도 계측 신호에서의 잡음 제거 기법 및 이중 적분을 통한 실시간 변위 추정 기법을 제안한다. 효과적인 잡음제거기법으로는 계측 가속도의 주파수 분석 후 얻은 피크 주파수 영역만을 고려하는 다중대역 통과 필터가 제안되었다. 이 새로운필터링 기법과 이중 적분에 의한 변위 추정기법이 본 연구에서 제안되었다. 제안 기법의 정확성 및 합리성은 수치해석 예제의결과를 통해 검증되었는데 기존에 많이 쓰이는 고역통과 및 대역통과 필터기법이 적용된 변위 추정기법과 비교되어 그 정확성이 정량적으로 입증되었다.

우간다 농업협동조합

김승준,정희율 한국농촌경제연구원 2015 세계농업 Vol.183 No.-