• Earthquakes and Structures
• /
• 제22권3호
• /
• pp.319-330
• /
• 2022

Retrofit of soft-story buildings due to seismic loads using Gap-Inclined-Brace (GIB) system is considered a new retrofit technique that aims to maintain both strength and stiffness of structure. In addition, it provides more ductility and less P-delta effect, and subsequently better performance is observed. In this paper, the effect of the eccentricity between GIB and the retrofitted column due to installation on the efficiency of the retrofitting system is studied. In addition, a modification in the determination method of GIB properties is introduced to reduce the eccentricity effect. Also, the effect of GIB system on the seismic response of mid-rise buildings with different heights considering soft-story at various heights has been studied. A numerical model is developed to study the impact of such system on the response of retrofitted soft-story buildings under the action of seismic loads. To achieve that goal, this model is used to perform a numerical investigation, by considering five case study scenarios represent several locations of soft-story of two mid-rise reinforced concrete buildings. At first, Non-linear static pushover analysis was carried out to develop the capacity curves for case studies. Then, Non-linear time history analyses using ten earthquake records with five peak ground accelerations is performed for each case study scenario before and after retrofitting with GIB. The results show that large GIB eccentricity reduce the ultimate lateral resistance and deformation capacity of the retrofitting system. Moreover, the higher the retrofitted building, the more deformation capacity is observed but without significant increase in ultimate lateral resistance.

• 한국농촌건축학회논문집
• /
• 제24권4호
• /
• pp.1-8
• /
• 2022

This study aims to investigate the gap in accessibility to urban planning facilities between living spheres in local small and medium-sized cities. In this study, OD data between administrative dongs of public transportation users was constructed to analyze the living shpere, and community analysis was conducted based on cohesion between data. As a result of the analysis, it was confirmed that a total of 10 clusters (mid-living areas) were formed, and the topographical difference between the 11 middle living areas established in the existing Jinju City Basic Plan and the single living areas were actively exchanged to form a community with other administrative dongs. Next, the analysis of the service area of urban planning facilities for mid-living areas was conducted based on the road network. As a result of analyzing the area accessible within 5, 10, and 15 minutes, educational facilities, public facilities, cultural facilities, tourism, and green facilities could be reached within 15 minutes in most mid-living areas. On the other hand, there were many areas where access to transportation facilities, medical facilities, and cultural facilities was difficult within 15 minutes. In particular, the accessibility of the outer living area and the central living area were different. To improve the quality of life of citizens, using urban planning facilities in Jinju-si and establishing related plans in urban basic plans, it is necessary to conduct a study on service areas through network analysis.

• The Journal of the Acoustical Society of Korea
• /
• 제21권2E호
• /
• pp.81-90
• /
• 2002

Single absorbing materials and Helmholtz resonators have limited absorption characteristics over limited frequency ranges due to their structures and properties. Porous materials are highly absorptive for mid and high frequency ranges, while they have little sound absorption for low frequency sounds. Helmholtz resonators are generally used to absorb sound energy for a specified frequency range. Hence they have limited capability in controlling the overall acoustic properties of a space. Not much has been known about useful finishing materials which have enough rigidity and absorption over broad frequency range, in spite of wide demands from acoustic designers and consultants. The present work measured and analyzed absorption characteristics of a slit absorber by varying surface materials, depths of air gap, dimensions of slat and slit widths. It was found that the narrower the slit width, the larger the absorptions over the wide frequency ranges and the pattern was dependent on the presence of porous material. Narrower slat's width tend to increase the slit absorber's absorption more or less. Absorption coefficients at low frequency ranges were dramatically improved (from 0.23 to 0.56) by increasing air gap when porous materials were present.

• 노동경제논집
• /
• 제31권3호
• /
• pp.75-105
• /
• 2008

본고는 노조 유무별 부문 내부의 임금구조 차이를 고려하여 1988년 이후 20년간 노조의 임금프리미엄과 특징적 변화를 분석했다. 추정된 노조의 임금 프리미엄은 20년간 평균 3.4%이며, 남성의 노조프리미엄은 전체 근로자보다 낮았다. 1997년 이전에는 1.7%였으나 그 이후에는 5.1%로 급증했다. 20년간 노조 임금프리미엄의 추세는 경기역행적이며, 이는 향후 노조 임금프리미엄의 변화를 전망하는 주요한 틀이 될 것이다. 외환위기 이후 노조 유무별 임금격차의 급등은 근로자 및 기업 특성 등 구성적 요소의 변화가 핵심이라는 점도 중요한 의미를 갖는다.

• 조명전기설비학회논문지
• /
• 제12권1호
• /
• pp.3-11
• /
• 1998

스페이서 표면 파티클에 의한 오염의 영향은 SF6GIS의 절연내력을 현저히 감소시킨다. 이와 관련해서 우리는 평행평판전극 구성으로 SF6가스중에서 금속 및 비금속 파티클의 위치 및 형태를 변화시키면서 교류전압에서 섬락전압 특성과 파괴 기구에 대해서 연구했다. 주된 결과는 $\circled1$파티클 위치에 대한 섬락전압 감소의 영향은 갭중간에서 가장 적고 전극에서 미소간극 분리된 경우의 영향이 가장 커다. $\circled2$ 섬락전압 감소가 크게 되는 금속 파티클 일수록 FOV 포화 현상은 낮은 압력 영역으로 이동된다. $\circled3$0.6[mm]이하의 비금속 파타클은 섬락전압에 그의 영향을 미치지 않는다.

• Steel and Composite Structures
• /
• 제38권4호
• /
• pp.365-380
• /
• 2021

Although traditional steel-concrete composite beams have excellent structural characteristics, it cannot meet the requirement of quick assembly and repair in the engineering. This paper presents a study on static behavior of bolt connected steel-concrete composite beam without post-cast zone. A three-dimensional finite element model was developed with its accuracy and reliability validated by available experimental results. The analysis results show that in the normal service stage, the bolt is basically in the state of unidirectional stress with the loss of pretightening can be ignored. Parametric studies are presented to quantify the effects of the post-cast zone, size and position of splicing gap on the behavior of the beam. Based on the studies, suggested size of gap and installation order were proposed. It is also confirmed that optimized concrete slab in mid-span can reduce the requirement of construction accuracy.

• Asia Marketing Journal
• /
• 제13권3호
• /
• pp.265-274
• /
• 2011

본 사례는 중형차 시장의 선도 브랜드인 기아자동차 K5가 어떻게 중형차 시장에 성공적으로 포지셔닝 하였는지를 분석하고 있다. 기아자동차가 K5를 출시하기 전까지 쏘나타와 SM5는 각 브랜드를 선호하는 고객들의 지지를 기반으로 중형차 시장에서 1, 2위를 다투면서 오랫동안 소비자의 사랑을 독차지해 왔다. 경쟁사들이 지속적으로 새 브랜드나 신 모델을 출시함에 따라 쏘나타와 SM5도 새로운 버전의 차를 출시해야 한다는 압박을 받게 된다. 하지만, 시장의 새로운 트랜드를 따라 잡기위해 출시된 YF 쏘나타는 기존 디자인에 비해 너무나 달라 이질감을 느끼게 하였으며, New SM5는 달라진 것이 거의 없는 구형차 라는 이미지로 받아들여졌다. 두 브랜드가 고객들을 제대로 만족시키지 못하고 있을 때, 기아자동차 K5는 중형차 소비자를 만족시킬 수 있는 제품에 대한 기회를 포착하고 중형차 시장에서 현재 제공되는 가치와 소비자들이 원하는 가치의 차이를 채워줌으로써 준중형 고객의 업그레이드 수요와 중형차 대체 수요를 만족시키는 성과를 거두었다. K5는 고객들이 원하는 가치를 찾고 그 가치를 성공적으로 제안하였다. 본 사례는 포화상태에 있는 자동차 산업에서 성공적인 포지셔닝 전략을 통해 신 시장을 개척하는 과정을 잘 보여주고 있다. 기아자동차 K5의 성공적인 포지셔닝 전략을 크게 디자인 혁신, 시장분석, STP, 그리고 출시전략의 4가지 축으로 설명하고 있다. 기아자동차 K5의 성공적인 포지셔닝 전략은 신 시장 개척을 위한 포지셔닝 전략을 계획하고 있는 많은 기업에게 의미 있는 시사점을 제공해 준다.

• The Journal of Korean Physical Therapy
• /
• 제27권3호
• /
• pp.140-146
• /
• 2015

Purpose: To determine the effects of 630 nm light emitting diode (LED) on full-thickness wound healing. Methods: Twelve male Sprague-Dawley rats were randomly divided into LED (n=6) and control group (n=6). Two $19.63mm^2$ wounds were created on the mid dorsum. LED group received a 630 nm LED irradiation with $3.67mW/cm^2$ for 30 minutes ($6.60J/cm^2$) for 7 days, while control group received sham LED irradiation. Epithelial gap, collagen density, ${\alpha}$-SMA fibroblast and PCNA keratinocyte were measured on histochemical and immunohistochemical staining using image analysis system. An independent t-test was conducted to compare the difference between groups. Results: The wound closure rate, collagen density, ${\alpha}$-SMA fibroblast number, epithelial gap and PCNA keratinocyte number have shown no significant difference between LED and control group at day 3 after the treatment. At day 7 after the treatment, the wound closure rate in LED group was increased when compared with control group (p<0.05). The collagen density (p<0.05) and ${\alpha}$-SMA immunoreactive fibroblast number (p<0.001) were increased when compared with control group at day 7. The epithelial gap in LED group was significantly shorten than control group at day 7 (p<0.01). The PCNA positive cell number in LED group was higher than control group at day 7 (p<0.01). Conclusion: 630 nm LED with $3.67mW/cm^2$, $6.60J/cm^2$ accelerate collagen deposition by stimulating fibroblasts, and enhance wound contraction by differentiating myofibroblasts in the dermis, and accelerate keratinocyte proliferation by facilitating DNA synthesis in the epidermis. It may promote the healing process in proliferation stage of wound healing.

• 한국세라믹학회지
• /
• 제44권2호
• /
• pp.89-92
• /
• 2007

PbSe, with a band gap in the mid-infrared and a samll effective mass, is an interesting material for optical and electrical applications in infrared region. Various colloidal synthetic routes for synthesizing PbSe quantum dot nanoparticles have been developed in the last couple of years. In this work, stable colloidal solutions containing crystalline PbSe particles in the order of 5-15 nm were synthesized using different amount of acetic acid in high boiling coordinating solvents. The size and shape of PbSe nanoparticles was greatly influenced by coexistence of acetic acid in synthetic medium. It was observed by TEM that the shape of PbSe nanoparticles with different amount of acetic acid was changed from spherical to cube or star types.

• Journal of Chest Surgery
• /
• 제24권11호
• /
• pp.1107-1114
• /
• 1991

We have experienced fourteen patients of esophageal perforation at the department of thoracic and cardiovascular surgery, Chonbuk National University Hospital during the period from mar. 1980 to Oct. 1990. The ratio between male and female patients was 5 : 9, and their age ranged from 22 years to 69 years. The causes of th eesophageal perforation were iatrogenic in 6 cases, foreign body 5 cases, diverticulitis 2 cases, and postpneumonectomy 1 case. The locations were cervical esophagus in 2 cases, upper thoracic in 2 cases, mid-thoracic 4 cases, and lower thoracic 6 cases. The underlying diseases associated with perforation were lye stricture, diverticulum, achalasia, and postpneumonectomy empyema. The treatments were supportive in 6 cases and combined with surgical measures in 8 cases. surgical measurs were as follows : incision and drainage in 2 cases, esophagectomy with esophagogastrostomy 3 cases, esophagocardiomyotomy with partial fundoplication in 1 case, simple closure with myoplasty and thoracoplasty 1 case, and empyema drainage and gastrostomy 1 case. There was no mortality.