• 한국산학기술학회논문지
• /
• 제19권9호
• /
• pp.333-340
• /
• 2018

최근 비정형 건축구조물은 건설 산업의 디지털화로 인해 점점 더 복잡한 형상으로 디자인되고 있다. 특히, 외관 및 내부 구성요소들의 단면이 자유롭게 변화되는 곡선 및 곡면의 형태를 띠고 있으며, 그로 인해 곡률을 가진 구조부재들이 빈번히 나타나고 있다. 이러한 구조물의 모형을 작성하고 안정성을 평가를 하는데 있어, 고전적 방식의 유한요소 해석기법이 적용된 상용프로그램들은 신속한 형상 모델링이 불가능하여 생산성 저하를 초래하고 있다. 따라서 본 연구에서는 선행연구를 통해 개발된 구조해석 통합시스템을 확장하여 비정형 외피 형상을 신속하게 모델링하고, 그 결과물을 이용하여 외피를 구성하는 프레임 구조를 자동으로 생성할 수 있는 전후처리 모듈을 개발하였다. 본 연구에서 개발된 전후처리 모듈은 스플라인 곡선 및 곡면의 세분화 알고리즘을 적용하여 NURBS곡면의 형상정보를 통해 해석요소를 자동으로 생성하고, 해석 후의 변형 형상을 보다 현실적으로 가시화 시킬 수 있도록 개발되었다. 본 연구를 통해 개발된 전후처리 모듈은 복잡한 곡면 형상을 신속하게 구축하고, 그에 따른 하부 골조시스템의 해석모형을 자동으로 생성할 수 있어 향후 비정형 건축물 설계의 생산성 향상에 기여할 수 있을 것으로 판단된다.

• Archives of Plastic Surgery
• /
• 제34권4호
• /
• pp.432-435
• /
• 2007

Purpose: The jejunal free flap has the shorter ischemic time than other flap and requires a laparotomy to harvest it. As the evaluation of the perfusion the buried flap is very important, the perfusion of the buried jejunal free flap requires monitoring for its salvage. We tried to improve the monitoring flap method in the jejunal free flap and examined its usefulness. Methods: From March 2002 to March 2006, the monitoring flap method was applied to 4 cases in 8 jejunal free flaps for the pharyngeal and cervical esophageal reconstructions. The distal part of the jejunal flap was exposed without suture fixation through cervical wound for monitoring its perfusion. The status of perfusion was judged by the color change of jejunal mucosa and mesentery. If necessary, pin prick test was performed. Doppler sonography was applied to mesenteric pedicle of the monitoring flap in case of suspicious abnormal circulation. Results: The monitoring flap shows no change in 3 cases, but the congestion happened in one case at the 12 hours after the operation. This congestion was caused by the twisting or kinking of the mesenteric pedicle of the monitoring flap. So, we fixed up the monitoring flap close to adjacent cervical skin for prevention of rotation. Finally, the main part of transferred jejunal flap was intact. Conclusion: The success of a jejunal free flap depends on close postoperative monitoring and early detection of vascular compromise. So, various monitoring methods have been tried, for instance, direct visualization using a fiberoptic pharyngoscope, through a Silastic window placed in the neck flap, or external surface monitoring with an Doppler sonography, use of a buried monitoring probe. But, all of the above have their own shortcomings of simplicity, non-invasiveness, reliability and etc. In our experience, monitoring flap can be a accurate and reliable method.

• Toxicological Research
• /
• 제21권1호
• /
• pp.45-49
• /
• 2005

The purpose of this study is to evaluate the free radical scavenging ability and xanthine oxidase inhibitory activity of a complex herbal bath consisted of Artemisiae argyi folium, Angelicae sinensis radix, Ligustici wallichii radix and Angelicae tuhuo radix, and its potential irritation response were also tested for safety use in the rabbits. For antioxidative activity, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the complex herbal bath were examined at five different concentrations (0, 250, 500, 1000 and 2000 ㎍/ml). The concentration of the complex herbal bath required for scavenging DPPH free radical by 50% was 897.2 ㎍/ml. In the inhibition of xanthine oxidase (XO) activity, the concentration of the complex herbal bath required for 50% of inhibition was 221.4 ㎍/ml. In the skin irritation study in rabbit, all animals survived for the duration of the study and the examined skin exhibited no edema, erythema, and eschar formation. In the ocular irritation study in rabbit, after application of the sample to eyes, all of the eyes were normal. In summary, the complex herbal bath has potent antioxidant effects against the DPPH radical and XO and was considered to be a non-irritation bath for safety use.

• Animal cells and systems
• /
• 제16권3호
• /
• pp.207-214
• /
• 2012

Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-b1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.

• 한국경제지리학회지
• /
• 제17권4호
• /
• pp.759-770
• /
• 2014

본 논문은 시간의 제약이 활동 및 통행으로 연결됨을 확인하는 것이 목적이며, 이를 위해 우리나라 수도권 전일제 근로자의 평일 시간이용에 집중하였다. 특히, 우리나라의 근로자는 다른 OECD 국가의 근로자보다 근로시간에 할애하는 시간이 압도적으로 많다. 이로 인해 나타나는 시간부족현상은 긴 근로 시간으로 인해 근로 외 활동에 제약이 생기는 문제가 나타날 수 있다는 차원에서 삶의 질 문제를 논의해볼 수 있다. 이와 같은 배경에서, 수도권에 거주하는 전일제 근로자의 시간 제약이 활동 및 통행 제약에 영향을 끼치는지 확인하기 위해 2010 가구통행실태조사의 수도권 자료를 활용하여 통행사슬(trip-chain)을 구성하였으며, 이를 유형별로 구분하고 유형에 따른 시간이용패턴을 분석했다. 그 결과, 시간부족현상이 전반적인 활동의 제약으로 나타났으며, 이는 활동패턴에 영향을 끼치는 것으로 나타났다. 본 논문은 근로시간 및 교통에 관련된 정책 대안에 함의를 가지고 있으며, 향후 활동기반 관점의 삶의 질 측정에 도움이 될 것으로 생각된다.

• 대한치과보철학회지
• /
• 제38권4호
• /
• pp.472-483
• /
• 2000

Before impression making in the fixed restorations or other prosthesis, hemostatic solutions are used for hemostasis and moisture control. Hemostatic solutions effectively control bleeding but their major ingredients, acid removes smear layers which are formed in the tooth preparation, exposes the dentinal tubular orifices which are occluded by smear layers, makes dentinal tubular fluid displace more easily to the various external stimulus, and according to the hydrodynamic theory, consequently causes dentin hypersensitivity. To know the effect of hemostatic solutions on dentin permeability, coronal dentin discs, 1mm in thickness, were prepared from extracted third molars free from decay and wear, and a split chamber device was used. Hydraulic conductance values and SEMs, which were measured before and after treatment with $Astringedentr^{(R)},\;Altract^(R)\;and\;Epri-dent^{(R)}$, were compared and ana-lysed. The following conclusions were drawn: 1. Hydraulic conductance values which were measured after the treatment of hemostatic solutions were increased in all groups(p<0.05). 2. %change values of hydraulic conductance were compared but no significant difference was found among the three hemostatic solutions(p<0.05). 3. On SEM observations of all groups, after treatment smear layers were removed and dentinal tubular orifices were partially exposed. On the basis of these conclusions, the reckless use of hemostatic solutions should be restricted, and when in use, various methods should be considered to protect dentin.

• 한국조리학회지
• /
• 제18권2호
• /
• pp.206-215
• /
• 2012

본 연구에서 오디를 첨가하여 당화와 식혜의 미치는 영향에 대한 결과는 다음과 같다. 당화기간 동안의 pH의 변화는 오디의 첨가량이 증가할수록 pH는 감소하였으며 당화 4시간 이후에는 큰 변화를 보이지 않았다. $^{\circ}Brix$는 4시간까지는 매시간 1 $^{\circ}Brix$이상 증가하고, 4시간 이후는 변화폭이 1 $^{\circ}Brix$이하로 감소하여 당화시간은 4-5시간이 적당한 것으로 보여진다. 오디 식혜의 색도는 L 값은 감소하고 a 값과 b 값은 증가하였고 오디 식혜의 DPPH free radical 소거활성과 SOD 유사활성은 오디의 첨가량이 증가할수록 증가하였으며, 오디의 anthocynin색소에 미생물 억제 효과가 있으며 오디 식혜의 기호도는 10% < 30% < 15% < 20% < 0% < 25% 이었고 오디의 첨가량은 10% 초과 25% 이하가 바람직한 것으로 보여 지며 오디의 첨가량이 증가할수록 오디 식혜의 당도는 증가하여 오디의 첨가는 식혜의 설탕 사용량을 감소시킬 것으로 보여 지며 제품의 색깔과 산미를 부여하여 기호를 증진시킬 것으로 사료된다.

• Korean Journal of Radiology
• /
• 제24권7호
• /
• pp.640-646
• /
• 2023

Objective: Prospective studies on postoperative residual breast tissue (RBT) after robotic-assisted nipple-sparing mastectomy (R-NSM) for breast cancer are limited. RBT presents an unknown risk of local recurrence or the development of new cancer after curative or risk-reducing mastectomies. This study investigated the technical feasibility of using magnetic resonance imaging (MRI) to evaluate RBT after R-NSM in women with breast cancer. Materials and Methods: In this prospective pilot study, 105 patients, who underwent R-NSM for breast cancer at Changhua Christian Hospital between March 2017 and May 2022, were subjected to postoperative breast MRI to evaluate the presence and location of RBT. The postoperative MRI scans of 43 patients (age, 47.8 ± 8.5 years), with existing preoperative MRI scans, were evaluated for the presence and location of RBT. In total, 54 R-NSM procedures were performed. In parallel, we reviewed the literature on RBT after nipple-sparing mastectomy, considering its prevalence. Results: RBT was detected in 7 (13.0%) of the 54 mastectomies (6 of the 48 therapeutic mastectomies and 1 of the 6 prophylactic mastectomies). The most common location for RBT was behind the nipple-areolar complex (5 of 7 [71.4%]). Another RBT was found in the upper inner quadrant (2 of 7 [28.6%]). Among the six patients who underwent RBT after therapeutic mastectomies, one patient developed a local recurrence of the skin flap. The other five patients with RBT after therapeutic mastectomies remained disease-free. Conclusion: R-NSM, a surgical innovation, does not seem to increase the prevalence of RBT, and breast MRI showed feasibility as a noninvasive imaging tool for evaluating the presence and location of RBT.

• Journal of Microbiology and Biotechnology
• /
• 제19권5호
• /
• pp.468-473
• /
• 2009

The antibiotic meroparamycin was produced in the free culture system of Streptomyces sp. strain MAR01. Five solid substrates (rice, wheat bran, Quaker, bread, and ground corn) were screened for their ability to support meroparamycin production in solid-state fermentation. In batch culture, wheat bran recorded the highest antibacterial activity with the lowest residual substrate values. The highest residual substrate values were recorded for both ground corn and Quaker. On the other hand, no antibacterial activity was detected for rice as a solid substrate. The use of the original strength of starch-nitrate medium in the solid-state fermentation gave a lower antibacterial activity compared with the free culture system. Doubling the strength of this medium resulted in the increase in the activity to be equivalent to the free culture. The initial pH (7.0) of the culture medium and 2 ml of spore suspension (1 ml contains $5{\times}10^{9}spores/ml$) were the optima for antibiotic production. The water was the best eluent for the extraction of the antibiotic from the solid-state culture. Ten min was enough time to extract the antibiotic using a mixer, whereas, 60 min was required when shaking was applied. Semicontinuous production of meroparamycin using a percolation method demonstrated a more or less constant antibacterial activity over 4 runs ($450-480{\mu}g/ml$). The semicontinuous production of the antibiotic was monitored in a fixed-bed bioreactor and the maximum activity was attained after the fourth run ($510{\mu}g/ml$) and the overall process continued for 85 days.

• 한국콘텐츠학회논문지
• /
• 제20권5호
• /
• pp.467-475
• /
• 2020

IPTV VOD 이용률이 증가하면서 VOD 이용패턴에 대한 심도깊은 연구의 필요성이 증대되고 있다. 이 논문은 VOD이용자를 유료VOD이용자와 무료VOD이용자로 구분하고 이용동기, 다양한 이용행태, 인구통계학적 변인 등 요인들이 이 두 그룹의 차이에 미치는 영향을 실증적으로 분석했다. 연구결과 유료VOD이용자와 무료 VOD이용자 간 차이에 영향을 미치는 요인은 사회적 동기, VOD 만족도, 홀드백 종료후 이용, 광고스킵 지불의향, VOD이용비중, VOD이용포기경험, TV시청시간, SVOD이용시간 등이었는데, VOD만족도를 제외한 모든 변인들이 유료VOD이용자의 특성을 정(+)적으로 예측했다. 추가로 VOD와 SVOD(유료OTT서비스) 이용간 관계를 분석결과 유료VOD이용자가 무료이용자보다 SVOD를 VOD의 대안서비스로 이용하는 비중이 더 높았다. 선행연구들에 비해 이 연구는 그동안 파편적으로 진행되었던 VOD 이용관련 변인들을 종합적으로 고려했다는 점에서 차별성을 갖는다.