• Clinics in Shoulder and Elbow
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• 제27권1호
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• pp.26-31
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• 2024

Background: The coracoacromial ligament (CAL) is frequently observed to be damaged during arthroscopy and it is unclear how demographic, anatomic, and radiographic factors are related to CAL degeneration in full-thickness rotator cuff tears. Methods: A prospective study was conducted of patients at a single institution undergoing shoulder arthroscopy for first-time, full-thickness rotator cuff tears. We evaluated preoperative anteroposterior radiographs to obtain critical shoulder angle, glenoid inclination, acromial index, acromiohumeral distance, lateral acromial angle, and acromial morphology. We documented CAL quality, rotator cuff tear size and pattern during arthroscopy. Multiple logistic regression was used to identify predictive factors for encountering severe CAL fraying during arthroscopy. Results: Shoulders had mild CAL degeneration in 58.1% of cases, whereas severe CAL degeneration was present in 41.9% of shoulders. Patients with severe CAL attrition were significantly older (62.0 years vs. 58.0 years, P=0.042). Shoulders with severe CAL attrition had large rotator cuff tears in 54.1% of cases (P<0.001), and tears involving the infraspinatus (63.2% vs. 29.6%, P=0.003). The severe degeneration group was more likely to have a larger critical shoulder angle measurement on preoperative radiographs than those in the mild attrition group (36.1°±3.6° [range, 30°-45°] vs. 34.1°±3.8° [range, 26°-45°], P=0.037). Conclusions: While the clinical impact of CAL degeneration remains uncertain, increased severity of CAL degeneration is associated with older age, larger rotator cuff tear size, presence of infraspinatus tearing, and increased preoperative critical shoulder angle. Level of evidence: III.

• 한국조경학회지
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• 제39권5호
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• pp.111-118
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• 2011

건강과 삶의 질 향상에 대한 관심이 커짐에 따라 도시녹지가 가져다 주는 건강편익이 크게 주목되고 있지만, 이에 관한 객관적이고 과학적인 데이터는 매우 부족한 실정이다. 따라서 본 연구에서는 도시녹지가 가져다 주는 건강편익에 대한 과학적 자료를 얻기 위해 생리적, 심리적 지표를 활용하여 실험을 실시하였다. 과거병력이 없는 20대 남자 대학생 20명이 실험에 참가하였고, 자극은 녹지와 도시에서 실제의 경관을 15분간 감상하는 것으로 하였다. 이번 연구는 충남대학교 의학전문대학원 생명윤리심사위원회의 승인을 받은 후 실시되었다. 녹지와 도시에 대한 생리반응을 분석한 결과, 도시에 비해 녹지에서 심박동수가 현저히 감소하였고, 안정상태에서 증가하는 부교감신경활동이 유의하게 향상되었으며, 스트레스호르몬의 일종인 코티솔 농도가 낮아지는 경향이 보였다. 심리반응에 있어서는 부정적인 감정과 정신상태가 녹지에서 보다 유의하게 낮아진 반면, 활력은 유의하게 증가하였다. 이번 연구의 결과는, 녹지를 접하는 것이 심리적 변화뿐만 아니라 인체의 자율신경계와 내분비계 활동에 긍정적 변화를 가져다 준다는 것을 보여주는 것으로써, 녹지가 도시민의 건강증진과 관련하여 매우 직접적인 환경요인이 될 수 있음을 과학적으로 뒷받침한다고 할 수 있다.

• Journal of Mechanical Science and Technology
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• 제20권1호
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• pp.59-65
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• 2006

A half-scaled large test model for the main components of the real annular structure was built and the thermal behaviors were experimented and obtained by thermal cyclic loads. The model design and the test conditions for the thermal loads were determined to take into consideration the thermal and mechanical loads acting on the real annular structure by finite element analyses. Temperature profiles and strains of the main components of the model were measured at an early stage of the test and periodically throughout the test in the given test conditions. After completion of the thermal cyclic tests, no evidence of crack initiation and propagation were identified by a dye penetration test. The measured strains at the critical parts were slightly increased proportionally with the increase in the number of the thermal cycles.

• 한국소음진동공학회논문집
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• 제13권5호
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• pp.341-347
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• 2003

This paper presents an improved escalator dynamic model so as to reflect the experimental observation on the pseudo-resonance affected by load applied. The experimental evidence reveals that backlash on gearbox as well as sag of driving Chain are most critical factors to the pseudo-resonance in escalators. The dynamic model effectively reflects vibration characteristics measured in real escalators with respect to different conditions of driving chain and the number of passengers. For validation of the dynamic model developed. numerical results from the model are compared with experimental results. The developed model and its simulation results are used rigorously for the design of escalator systems in enhancing the ride comfort.

• 한국논리학회:학술대회논문집
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• 한국논리학회 2008년도 하계학술 발표회
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• pp.73-92
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• 2008

Describing a physical system in idealized terms involves making literally false claims about the system. Given this, it is puzzling that justified beliefs about physical systems can be formed by starting with idealized descriptions and then performing mathematical calculations. I argue that this puzzling aspect of idealizations cannot be easily removed by introducing talk of approximations. I go on to develop an account of how this curious feature of idealizations is to be understood. My account requires us to reassess what precisely we take the laws of physics to be saying, and also has consequences concerning the kind of evidence we can have for thinking that mathematics is the 'language of nature'. Finally, some critical comparisons are made with the so-called model-based account of scientific laws developed by Cartwright and Giere.

• 한국정보시스템학회지:정보시스템연구
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• 제11권2호
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• pp.47-72
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• 2002

In the beginning of new millennium, Business-to-Business(B2B) Electronic Commerce(EC) is a hot issues of the world business and economic communities. The market of B2B EC is increasing rapidly, and become a more complex and competitive because many participants and intermediaries are play on their own objectives and strategies. To cope with the situation, participants of B2B EC market should make play with a competitive strategies. So, the participant enterprises must know the critical success factors of their own EC market. This study identifies B2B EC success factor measurement sets, and explores several success factors based on the perceived importance of B2B EC practitioner in the manufacturing enterprises. The study tests the differences of success factors by IS level, EC business model characteristics, and EC introduction and operating characteristics.

• 천문학회지
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• 제37권5호
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• pp.593-596
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• 2004

We introduce a method of identifying evidence of shocks in the X-ray emitting gas in clusters of galaxies. Using information from synthetic observations of simulated clusters, we do a blind search of the synthetic image plane. The locations of likely shocks found using this method closely match those of shocks identified in the simulation hydrodynamic data. Though this method assumes nothing about the geometry of the shocks, the general distribution of shocks as a function of Mach number in the cluster hydrodynamic data can be extracted via this method. Characterization of the cluster shock distribution is critical to understanding production of cosmic rays in clusters and the use of shocks as dynamical tracers.

• Biomolecules & Therapeutics
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• 제12권4호
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• pp.198-201
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• 2004

This review focuses on finding neurochemical changes in physical dependence on butorphanol, a relatively potent mixed agonist-antagonist opioid analgesic agent that is five times more potent than morphine in antinociceptive effects. The chronic administration of butorphanol induces physical dependence. Withdrawal from such dependence can be reliably precipitated by administration of a narcotic antagonist, e.g., naloxone. Evidence for critical involvement of excitatory aminoacid (glutamate), opioid receptors, and phosphorylation of proteins in these phenomena is summarized.

• Tuberculosis and Respiratory Diseases
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• 제79권4호
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• pp.201-206
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• 2016

Active tuberculosis (TB) has a greater burden of TB bacilli than latent TB and acts as an infection source for contacts. Latent tuberculosis infection (LTBI) is the state in which humans are infected with Mycobacterium tuberculosis without any clinical symptoms, radiological abnormality, or microbiological evidence. TB is transmissible by respiratory droplet nucleus of $1-5{\mu}m$ in diameter, containing 1-10 TB bacilli. TB transmission is affected by the strength of the infectious source, infectiousness of TB bacilli, immunoresistance of the host, environmental stresses, and biosocial factors. Infection controls to reduce TB transmission consist of managerial activities, administrative control, engineering control, environmental control, and personal protective equipment provision. However, diagnosis and treatment for LTBI as a national TB control program is an important strategy on the precondition that active TB is not missed. Therefore, more concrete evidences for LTBI management based on clinical and public perspectives are needed.

• 한국환경보건학회지
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• 제36권2호
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• pp.77-81
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• 2010

Tobacco smoking and secondhand smoke exposure are linked to a number of adverse health outcomes. There is a new concept of thirdhand smoke that is residual tobacco smoke contamination remained after the cigarette is extinguished. This paper reviews published studies examining the residual tobacco smoke. Tobacco smoke can be attached to various surfaces and reemitted to air for long period of time. The dynamic process can allow thirdhand smoke exposure to tobacco smoke without direct exposure to secondhand smoke. One critical evidence of the thirdhand smoke exposure was significantly high urinary cotinine level of infant who did not have direct secondhand smoke exposure. Potential exposure to new and more potent chemicals generated from chemical reactions between residual tobacco smoke and ambient air pollutants can get more attention. Considering toxicity and exposure route, children are uniquely susceptible to thirdhand smoke exposure. The review provides strong background information for thirdhand smoke but warrant more researches on this issue.