• 천문학회보
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• 제38권2호
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• pp.56.1-56.1
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• 2013

Supernovae type Ia (SNe Ia) cosmology is providing the only direct evidence for the presence of dark energy. This result is based on the assumption that the look-back time evolution of SNe Ia luminosity, after light-curve shape correction, would be negligible. However, the most recent compilation of SNe Ia data shows systematic difference in the Hubble residual (HR) between the E and Sd/Irr galaxies, indicating that the light-curve fitters used by the SNe Ia community cannot quite correct for a large portion of the population age effect. In order to investigate this possibility more directly, we have obtained low-resolution spectra for 30 nearby early-type host galaxies. This data set is used to estimate the luminosity-weighted mean ages and metallicities of host galaxies by employing the population synthesis models. We found an interesting trend between the host galaxy age and HR, in the sense that younger galaxies have positive residuals (i.e., light-curve corrected SNe Ia luminosity is fainter). This result is rather independent of the choice of the population synthesis models employed. Taken at face value, this age (evolution) effect can mimic a large fraction of the HR used in the discovery of the dark energy. This result is significant at 1.4 - 3 sigma levels, depending on the light curve fitters adopted, and further observations and analyses are certainly required to confirm the trend reported here.

• 대한기계학회논문집
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• 제19권1호
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• pp.79-86
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• 1995

The structural materials for cryogenic technology have been recently developed to support the many modern large-scale application from superconducting magnets for nuclear fusion reactor, magnetic levitation railway to LNG tankers. However it is pointed out that quenching phenomenon is one of the serious problems for the integrity of these applications, which is mainly attributed to the rapid temperature rising in the material due to some extrinsic factors of structures. From the viewpoint of fracture mechanics, it is therefore very important to clarify the mechanism of temperature rising of structural material due to cyclic loading at cryogenic temperature. From this purpose, fatigue test was carried out for high manganese steel at liquid helium temperature(4.2K) using triangular stress waveform to identify both the mechanism of temperature rising near crack tip and the effect of loading stress waveform on temperature rising near crack tip and the effect of loading stress waveforms on temperature rising. As the results, two types of temperature rising, that is, regular and burst types were observed. And a periodical temperature rising corresponding to the stress waveforms was also found. The peaks of the temperature rising were recorded near both the maximum and the minimum values of the applied stress. The sudden temperature rises, which indicated the higher values than those of periodical temperature rises under the repetition of stress, were observed at the final region of crack growth. It was shown that the peak values of the temperature rising increased with stress intensity factor range.

• Structural Engineering and Mechanics
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• 제77권3호
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• pp.329-342
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• 2021

In this paper, the effect of different steel bar configurations on the quasi-static punching and impact response of concrete slabs was studied. A total of forty RC square slab specimens were cast in two groups of concrete strengths of 40 and 63 MPa. In each group of twenty specimens, ten specimens were reinforced at the back face (singly reinforced), and the remaining specimens were reinforced on both faces of the slab (doubly reinforced). Two rebar spacing of 25 and 100 mm, with constant reinforcement ratio and effective depth, were used in both singly and doubly reinforced slab specimens. The specimens were tested against the normal impact of cylindrical projectiles of hemispherical nose shape. Slabs were also quasi-statically tested in punching using the same projectile, which was employed for the impact testing. The experimental response illustrates that 25 mm spaced rebars are effective in (i) decreasing the local damage and overall penetration depth, (ii) increasing the absorption of impact energy, and (iii) enhancing the ballistic limit of RC slabs. The ballistic limit was predicted using the quasi-static punching test results of slab specimens showing a strong correlation between the dynamic perforation energy and the energy required for quasi-static perforation of slabs.

• 동의생리병리학회지
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• 제27권1호
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• pp.124-129
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• 2013

Embedding Therapy keep the stimulation to acupoint. Recently, Embedding Therapy is used for various disease and also studied in many different fields especially in China. In Korea, Embedding Therapy is studied and used for dermatology, face-lift, obesity, facial palsy most frequently. Chinese studies shows us Embedding Therapy could help musculoskeletal system disorder, lumbar herniated intervertebral disc, sprain, spinal canal stenosis. In Korea study concerning lumbar herniated intervertebral disc treatment used Embedding Therapy is few. This study's purpose is to ensure effect of Embedding Therapy at lumbar herniated intervertebral disc treatment. Four lumbar disc herniation patients had been treated with Embedding Therapy were described in this article. The patients(n=4) had been suffering from chronic lower back and leg pain that continued for more than 6 months. All patients had been diagnosed as lumbar disc herniation by MRI or CT, and treated with Embedding Therapy at least 2 times(7 days interval). 2 patients had been treated with concurrent treatment of acupuncture therapy, and the other 2 patients with concurrent treatment of acupuncture and herbal therapy. We observed 4 patients for more than 2 weeks, and their symptoms and quality of daily life had been improved. This suggests that lumbar disc herniation can be successfully recovered with Concurrent Embedding Therapy under conventional Korean Medical Treatment without side effects.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.787-796
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• 2017

A low dimensional stability and poor bending strength properties were main problems in particleboard manufacturing. The objective of this research was to evaluate the effect of mixed wood species and urea-formaldehyde (UF) or urea-melamine-formaldehyde (UMF) resins on the physical and mechanical properties of three-layer particleboards. The ratio of face/core/back layer was 1 : 2 : 1. The resin content of 12% for both UF resins and UMF resins (UF/MF = 70/30% w/w) was used. The results of this study showed that the utilization of S.mahagony shaving using both UF and UMF resins caused a decrease in the thickness swelling and water absorption of the boards. Thickness swellings of particleboard made of Sengon/Sengon/Sengon (SSS), Mahogany/Mahogany/Mahogany (MMM), Sengon/Mahogany/Sengon (SMS), and Mahogany/Sengon/Mahogany (MSM) were in the range of 23%, 12~16%, 14~16%, and 13~21%, respectively. The board bonded with UMF resin demonstrated better dimensional stability than that bonded with UF resin alone. Modulus of elasticity (MOE) and modulus of rupture (MOR) of particleboards made of S. mahagony shaving in the surface layer in both MMM and MSM boards were better than those of the SSS and SMS. MOE of MMM and MSM board was in the ranges of 24,000 to $26,000kg.cm^{-2}$ and 18,000 to $21,000kg.cm^{-2}$ respectively. Meanwhile, the MOR of board was in the ranges of 200 to $240kg.cm^{-2}$ and 190 to $228kg.cm^{-2}$, respectively.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.32-40
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• 2020

While the utilization of wood as a raw material in related industries has been increasing with the population increasing, the availability of wood from natural forests has continued to decline. An alternative to this situation is the manufacture of particleboard from non-wood lignocellulose materials through the modification of sandwich particleboard (SPb) using bamboo strands as reinforcement. In this study, strandsof belangke bamboo (Gigantochloa pruriens W) and tali bamboo (Gigantochloa apus) were utilized. The non-wood particles included sugar palm fibers, cornstalk, and sugarcane bagasse. The board was made in a three-layer composition of the face, back, and core in a ratio of 1: 2: 1. The binder used was 8% isocyanate resin. The sheet was pressed at a temperature of 160℃ for 5 min under a pressure of 3.0 N/㎟. Testing included physical and mechanical properties based on the JIS A 5908 (2003) standard, while acoustic testing was based on ISO 11654 (1997) standards. The results showed that using bamboo strands as reinforcement has an effect on the mechanical and physical properties of SPb. Almost all the types of boards met the JIS A 5908 (2003) standards, with the exception of thickness swelling (TS) and internal bond (IB) parameters. Based on the thickness swelling parameter, the C-type board exhibited the best properties. Overall, the B-type board thatused a belangke bamboo strand for the surface and sugarcane bagasse as the core underwent the best treatment. Based on the acoustical parameter, boards using a tali bamboo strand for the surface and sugar palm fiber as the core (E-type board) exhibited good sound absorption properties.

• 예술인문사회 융합 멀티미디어 논문지
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• 제6권11호
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• pp.519-528
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• 2016

현 문화재 교육방식은 대부분이 시대의 흐름과 기술의 발전에 적합하지 못한 단순 주입식이나 지식 전달로 이루어지고 있다. 이를 보강하기 위해서 동영상이나 영상을 이용한 멀티미디어 요소를 이용하고 있지만 여전히 한계가 있다. 주입식 교육은 지식전달이라는 목적은 달성하고 있지만 창의력과 사고력이 발달할 시기인 성장기 학습자의 흥미를 유발시키기에는 제약이 따른다. 본 논문에서는 이에 대한 해결방안으로 HMD를 이용한 VR 체험형 문화재 콘텐츠를 제안한다. 사용자의 간접 체험과 흥미를 유발하기 위하여 세계의 유명 관광 문화재를 선택하였다. 사용자의 직접적인 선택의 느낌을 부여하기위해서 Leapmotion 인터렉션을 사용하여 학습 참여도를 높이고자 하였다. 문화재에 대한 지식을 제공하는 것과 함께 퍼즐 게임을 즐기면서 문화재에 대한 인식을 증대하고자 하였다. 또한 360VR 동영상을 제공하여 체험과 더불어 시각적 몰입감을 제공하여 흥미를 유발하였다. 제안된 콘텐츠를 검증하기 위해 사용자평가를 실시하였다.

• Journal of Oral Medicine and Pain
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• 제43권2호
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• pp.27-33
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• 2018

Purpose: Many researchers have established a connection between sleep disturbances and the symptoms of temporomandibular disorder (TMD) in adults, but there are a few studies targeted at adolescents with TMD. The aim of this study was to analyze the sleep pattern of adolescents with TMD and to determine the effect of poor sleep quality on their clinical symptoms. Methods: The subjects were composed of 47 adolescents with TMD. The sleep pattern and preliminary information of patients were measured by self-reported questionnaires; Pittsburgh Sleep Quality Index (PSQI) and Questionnaire for TMD analysis. TMD pain was scored using the Numerical Rating Scale. The Kruskal-Wallis test, Mann-Whitney U test, Fisher's exact test and logistic regression were used for statistical analysis. Results: The poor sleeping group had statistically more females (25.00% males, 75.00% females) than the good sleeping group. As compared with that of good sleepers, sleep quality of poor sleepers was significantly worse in the items of subjective sleep quality, sleep latency, sleep duration, sleep disturbances, daytime dysfunction and global PSQI score. The sleep time of adolescents was much longer during vacation ($7.20{\pm}1.38hours$) than during school days ($6.10{\pm}1.26hours$). Poor sleep of patients was associated with the pain in the ear or in front of the ear, in the face, jaw, throat or temple and in neck or back. Adolescents with pain in those areas had significantly higher proportion of poor sleepers than adolescents with no pain in those areas. Conclusions: The high ratio of girls in poor sleeping group could reflect the greater prevalence of TMD in women than in men. Pain in peri-temporomandibular joint areas, neck or back could negatively influence sleep quality of adolescents with TMD.

• 만화애니메이션 연구
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• 통권41호
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• pp.153-168
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• 2015

영상을 통한 콘텐츠 유통 활성화는 안성지역 활성화 콘텐츠 산업에서 선순환 구조 구축의 필수조건이다. 2015년 국책 사업을 통해 안성지역 지자체에서 제작되고 있는 특수 영상 콘텐츠 제작의 애니메이션은 지역경제를 활성화시키기 위해 시에서 추진되고 있는 핵심 사업이다. 이 연구는 영상 콘텐츠 개발의 과정에서의 기획고찰과 디자인 작품 제작을 통해 시각적 제안을 하고자 한다. 캐릭터 개발 과정의 창의성 및 독창성을 비롯하여 심미적인 평가와 작품의 타당성, 비평성의 연구는 매우 중요하기에, 점차 활성화되고 있는 특수 영상(3D,4D)에서의 지방자치단체의 일반 기존 제작되어진 캐릭터와는 다른 방향의 캐릭터 개발 발전 방향을 위해서 실질적 개발의 비쥬얼이 제시되어져야 할 연구 과제일 것이다, 아울러 개발 진행 단계와 각 단계별로 평가 기준과 실질적 분석의 기획단계의 과정을 통해 제안된 작품이 주요 결과로서 제시되었다. 각 캐릭터 시안의 대한 기획과정의 연구들이 본론에서 제시되고, 결론부분에서 작품 완성 디자인이 중요하게 다루어 졌으며, 개발 사례에 대한 기획방향과 제시된 특수영상의 캐릭터의 특징들을 자세히 제시하였다. 실질 개발 과정에서의 선택과 평가가 객관적이고 결과 지향적이어야 하기에 특수영상의 실질적 캐릭터 작품을 기획과 결과 과정을 제시하며 발표하는 논문은 중요한 요청을 가지며, 제시된 디자인 결과물로서 실질적 가치 개발 창출에 의미를 가짐으로서 가시적 성과에 기여할 것으로 기대한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.247-252
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• 2006

오염 퇴적물내 중금속의 방출과 이에 따른 생이용성(bioavalability)은 기존의 가역 평형관계로써 설명하기에 불충분한 것으로 알려져 있다. 최근 연구결과에 의하면 이러한 탈착 저항성을 설명하기 위한 비가역적 모델에 의해 퇴적물내 중금속의 탈착저항성 부분이 존재함이 밝혀졌다. 탈착저항성에 대해서는 아직 충분한 규명이 이루어지지 않았으나, 오염물질의 노화(aging)에 의해 일단 탈착저항성을 띠게 되면 생이용성(bioavailability)이 감소되는 것으로 알려져 있다. 본 연구에서는 노화(aging)가 연안 퇴적물 내 납과 카드뮴의 흡/탈착 특성에 미치는 영향을 알아보기 위해 연속 탈착실험과 biphasic 탈착모델을 적용함으로써 납과 카드뮴의 탈착저항성을 규명하고자 하였다. 그리고 연속 추출 실험을 통해서 노화(aging)에 따른 퇴적물 내 납과 카드뮴의 흡착 기작을 규명하고자 하였다. 연속탈착 실험 결과 시간이 경과함에 따라 탈착저항성부분의 크기가 증가하였으며, 연속추출 실험 결과 납의 경우 carbonate fraction에서 추출된 납이 가장 많았으며, 노화(aging) 따라 exchangeable fraction에서 추출된 납이 감소하는 반면 reducible, organic material, residual fraction에서 추출된 납의 양이 증가하였다. 카드뮴의 경우 가장 많은 양이 추출된 단계는 exchangeable fraction이였으며, organic material fraction에서는 카드뮴이 추출되지 않았다. 노화(aging) 따라 reducible fraction과 residual fraction에서의 추출량이 증가하는 경향을 보였으나 그 양은 매우 적은 것으로 나타났으며, 노화(aging)에 따른 exchangeable fraction과 carbonate fraction에서의 추출량은 큰 변화가 없었다. 대해서는 북한지역의 분포상황을 밝혔다.것을 알 수 있었으며, 크롬과 비소의 경우는 초기에 많이 용출되고, 구리의 경우는 꾸준히 용출되는 것을 알 수 있었다. 3년 된 통나무집이 8년 된 통나무집보다. 용출양이 더 컸으며, 이는 CCA성분이 초기에 많이 용출된다는 것을 의미한다. 억제 효과를 나타내었고 Hep3B에서는 부탄을 분획물 (1 mg/mL)에서 82%의 비교적 높은 성장억제효과를 나타내었다.as a "front" and "back". Thus, Germany′s private space may face a genuine public space and street, which is rare in the Korean housing. Although the layout of indoor space in the korean housing tends to be open, such an openness may be outstanding in living and dining spaces, kitchen and various accesses to rooms. In the case of Germany, such indoor spaces are usually closed to each other. Thus corridors act to separate these spaces. Such differences are analysed to be due to the different perceptions of interpersonal and socio-cultural attributes as intra-family and inter-neighbor relationships or communications. 알 수 있었다.도 질소와 인산처럼 토양지지대가 있는 경우가 낮은 함량을 유지하였다.pe from the daily life, to fantasize and daydre