• Animal cells and systems
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• 제14권4호
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• pp.283-289
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• 2010

Ssanghwa-tang (SHT) is a traditional Korean herbal medicine widely prescribed to decrease fatigue following an illness. The purpose of this study was to investigate the effects of SHT on osteoclast differentiation in vitro, and on bone loss in ovariectomized (OVX) rats in vivo. SHT significantly reduced the receptor activator for the nuclear factor ${\kappa}B$ (NF-${\kappa}B$) ligand (RANKL)-induced tartrate-resistant acid phosphatase (TRAP) activity, and multinucleated osteoclast formation in RAW264.7 cells without affecting cell viability. In addition, SHT significantly attenuated RANKL-induced mRNA expression levels of c-Src and cathepsin K. To examine the in vivo effect of SHT on OVX-induced bone loss in OVX rats, we administered SHT (0.6 g/kg BID) orally to OVX rats for 12 weeks. SHT administration significantly blocked OVX-induced decrease of femoral bone mineral density (BMD) and femoral trabeculae in OVX rats. In conclusion, these results suggest that SHT treatment effectively prevents OVX-induced bone loss, and this effect may result from its inhibitory effect on osteoclast differentiation.

• 대한기계학회논문집A
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• 제41권10호
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• pp.997-1004
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• 2017

엘리베이터 와이어로프의 수명은 제품의 매우 중요한 특성 가운데 하나로서 사용자의 안전 및 장비의 정비 정책과 밀접한 관계가 있다. 엘리베이터 와이어로프의 수명을 사용조건에서 측정하는 것은 매우 비경제적이다. 이 연구에서는 엘리베이터 와이어로프 (8x19W-IWRC)의 가속열화시험 데이터를 활용하여 와이어로프의 수명을 추정하는 방법을 다루었다. 굽힘피로시험기를 이용하여 가속열화시험을 진행하였으며 가속변수로는 인장하중을 사용하였다. 와이어로프의 수명은 대수정규분포를 가정하였고, 선형회귀모형을 이용하여 가수명을 구한 후 가속수명모형을 이용하여 와이어로프의 수명을 추정하는 방법과 고장 확률에 대한 로지스틱 회귀모형을 이용하여 추정하는 방법을 제시하고 두 모형의 수명 추정결과를 비교하였다.

• 한국한의학연구원논문집
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• 제16권1호
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• pp.149-155
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• 2010

Objective : Ssangwha-tang is a traditional medicine formula widely prescribed for a decrease of fatigue after an illness in Korea. The aim of this study is to investigate the effect of Ssangwha-tang fermented by Lactobacillus fermentum (SF) on osteoclast differentiation in vitro and on bone metabolism of an ovariectomized rat in vivo. Methods : Tartrate-resistant acid phosphatase activity and staining were applied to evaluate the formation of osteoclasts. Ovariectomized rats were orally administrated with SF (30 ml/kg/day) for 12 weeks. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglyceride, phosphate, calcium levels were determined. Effect of SF on bone loss were studied by histological analysis and the measurement of bone mineral density. Results : SF significantly inhibited tartrate-resistant acid phosphatase activity and formation of osteoclasts in RAW264.7 cells stimulated by receptor activator for nuclear factor ${\kappa}B$ (NF-${\kappa}B$) ligand (RANKL). In addition, SF significantly decreased the level of triglyceride and increased the level of low-density lipoprotein. Moreover, the decrease of trabeculae of the femur was partially prevented in ovariectomized rats administrated with SF. Conclusions : SF treatment could prevent ovariectomy induced bone loss and its effects could be medicated by the inhibition of osteoclastogenesis.

• 방송공학회논문지
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• 제17권1호
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• pp.49-59
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• 2012

역사적으로 3D 영상은 몇 번의 부흥기를 맞이했음에도 불구하고 그 관심이 오래 지속되지 못했다. 많은 이유가 있겠지만, 많은 연구자들은 3D 영상이 가져오는 시각적 불편함과 같은 휴먼팩터 요인을 가장 큰 이유로 꼽는다. 영상 콘텐츠 연구에 있어 몰입과 피로도 등에 영향을 미치는 연구가 그간 2D 영상에서는 많이 이루어졌지만, 3D 영상 콘텐츠 시대에서는 기술적 발전에 관심이 집중되어 있을 뿐 영상 콘텐츠의 효과에 대해서는 연구가 등한시 되어 왔다. 본 연구에서는 3D 영상에 노출되었을 때 시청자들이 받아들이는 3D 영상의 특징을 어떻게 인식하는지, 피로도를 포함한 인상은 어떠한지, 그리고 프레즌스를 어떻게 느끼는지 척도를 개발하고 이를 평가하고자 했다. 연구 결과 3개의 변인(인지된 특성, 인상, 프레즌스)에서 총 17개의 요인을 추출했다. 17개의 요인 중에 13개 요인이 신뢰도 값이 .8 이상의 높은 값을 보였고, 나머지 요인들도 .65~.78로 받아들일 수 있는 정도의 값을 보였다.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.57-62
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• 2013

카트 차체에는 현가장치와 차동장치가 존재하지 않으므로 카트주행 중 발생하는 프레임의 변형은 탄성변형으로 인한 주행성능과 프레임의 피로수명에 영향을 미친다. 선회주행 시 비틀림 변형에 의한 카트의 거동은 이 두 가지 변형에 결정적 원인을 제공한다. 이러한 곡선구간에서 카트의 동적 거동을 분석하기 위하여 GPS를 이용하여 차량의 궤적을 추적하고 카트 프레임 강에 작용하는 비틀림 응력을 측정하였다. 레저와 레이싱 카트 프레임의 기계적 성질을 파악하기 위해 재질 분석과 인장시험을 실시하여 각 프레임의 재료 특성을 분석하였다. 비틀림 응력집중과 프레임 비틀림은 프레임 해석을 통해 조사되었다. 또한 주행 분석 장치를 이용하여 레저와 레이싱 카트를 각 조건별로 실차실험을 수행하였고, 이를 통해 곡선구간에서 카트의 주행거동을 분석하였다. 선회주행 시 차량에 원심력에 의한 하중이동의 현상이 발생했으며, 이로 인해 카트 프레임 강에 비틀림 응력이 발생하였다.

• 한방안이비인후피부과학회지
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• 제17권2호
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• pp.81-86
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• 2004

Objective: This study was designed to investigate clinical features of chronic urticaria and assess Korean traditional medical therapy on that. Methods: The ratio of male and female, duration of symptoms, personal history and family history of allergic diseases, serum IgE level, and suspected causes and provocation factors were investigated in 41 patients with chronic urticaria. And frequency of wheals, duration of wheals, number of wheals, itch severity, and antihistamine counts of 6-point(0-5) score was assessed in 26 patients. The change of total scores between baseline and follow up were analyzed using Wilcoxon signed-rank test(p〈0.05). Results: 1. The ratio of male and female was 1:1.28 and the mean duration of symptoms was 26.0 months. 2. The frequency of personal history and family history of allergic diseases was each 53.7$\%$ and 48.8$\%$ and 30.6$\%$ had over 200 IU／mL serum IgE level. 3. The suspected causes were none(43.9$\%$), foods(29.3$\%$), drugs(9.8$\%$) and stress(7.3$\%$). 4. The suspected provocation factors were foods(39.0$\%$), none(19.5$\%$), fatigue(17.0$\%$), heat and sweating(l4.6$\%$), pressure(12.2$\%$) and stress(9.8). 5. The total scores between baseline and follow up of 26 patients was lowered from 14.85${\pm}$3.80 to 7.65${\pm}$4.31 and it was significant statistically. Conclusions: Korean traditional medical therapy was proved to be effective on the chronic urticaria and we need to consider foods as important factor in both treatment and patient education of urticaria.

• Steel and Composite Structures
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• 제21권6호
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• pp.1227-1250
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• 2016

Most of the research work has been conducted on K-joints under static loading. Very limited information is available in consideration of fatigue strength of K-joints with concrete-filled chord. This paper aims to describe experimental and numerical investigations on stress concentration factors (SCFs) of concrete-filled circular chord and square braces K-joints under balanced axial loading. Experiment was conducted to study the hot spot stress distribution along the intersection of chord and braces in the two specimens with compacting concrete filled in the chord. The test results of stress distribution curves of two specimens were reported. SCFs of concrete-filled circular chord and square braces K-joints were lower than those of corresponding hollow circular chord and square brace K-joints. The corresponding finite element analysis was also conducted to simulate stress distribution along the brace and chord intersection region of joints. It was achieved that experimental and finite element analysis results had good agreement. Therefore, an extensive parametric study was carried out by using the calibrated finite element model to evaluate the effects of main geometric parameters and concrete strength on the behavior of concrete-filled circular chord and square braces K-joints under balanced axial loading. The SCFs at the hot spot locations obtained from ABAQUS were compared with those calculated by using design formula given in the CIDECT for hollow SHS-SHS K-joints. CIDECT Design Guide was generally quite conservative for predicting SCFs of braces and was dangerous for predicting SCFs of chord in concrete-filled circular chord and square braces K-joints. Finally SCF formulae were proposed for circular chord and square braces K-joints with concrete-filled in the chord under balanced axial loading. It is shown that the SCFs calculated from the proposed design equation are generally in agreement with the values derived from finite element analysis, which were proved to be reliable and accurate.

• 한국전자통신학회논문지
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• 제16권5호
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• pp.931-940
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• 2021

정보 관리가 조직의 주요 성공 요인으로 인식되면서, 조직은 엄격한 정보보안 정책 및 기술 도입 및 운영을 위한 투자를 높이고 있다. 그러나, 엄격한 정보보안 기술은 업무에 정보보안을 적용하는 조직원에게 기술스트레스를 발생시킬 수 있다. 본 연구의 목적은 정보보안 기술스트레스가 스트레인을 통해 정보보안 정책 저항에 미치는 영향을 제시하고, 업무기술 적합성이 기술스트레스의 영향을 완화하는 것을 확인하는 것이다. 본 연구는 선행연구를 통해 연구 모델 및 가설을 제시하였으며, 설문 조사를 통해 확보된 표본을 활용하여 구조방정식을 통한 가설검증을 하였다. 연구 결과는 정보보안 기술스트레스(과부하, 복잡성)가 정보보안 스트레인(걱정, 피로)을 통해 정보보안 정책 저항에 영향을 주었으며, 업무기술 적합성이 기술스트레스와 스트레인 간의 관계를 조절하는 것을 확인하였다. 본 연구는 정보보안 정책 및 기술의 적용 시 발생 가능한 조직원의 스트레스와 완화 방법을 제시한 관점에서 내부의 정보보안 수준 향상을 위한 전략적 방향을 제시한다.

• 한국안전학회지
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• 제34권2호
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• pp.40-47
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• 2019

The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.

• 대한지역사회영양학회지
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• 제26권5호
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• pp.382-395
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• 2021

Objectives: This study examined the nutritional status according to frailty status in the elderly at home. Methods: The participants were a total of 76 elderly at home living in Seo-gu, Gwangju, Korea. The nutritional status and frailty status were analyzed using the Nutrition Quotient for Elderly (NQ-E) and the Korean version of the Fatigue, Resistance, Ambulation, Illnesses and Loss of weight Scale (K-FRAIL), respectively. Results: The distribution of frailty status was robust (17.1%), pre-frailty (38.2%) and frailty (44.7%), and its distribution was significantly different in genders, age groups and the number of medications. The mean NQ-E score was 47.0 for total subjects, indicating a low grade. The scores of balance, diversity and dietary behavior factors were within the low grade, while the score of the moderation factor was within the medium-high grade. According to the frailty status, pre-frailty and frailty showed significantly higher scores for sugar-added beverages intake in the moderation constructs than robust. Robust showed significantly higher scores for the exercise hours and perception level for one's health than pre-frailty and frailty. Conclusions: These results suggest that nutrition status is associated with frailty status. Regular nutrition education and visiting nutrition service should be established to improve the balance and diversity of food intake and improve the dietary behavior of the elderly at home.