• 한국컴퓨터정보학회논문지
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• 제25권3호
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• pp.185-190
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• 2020

본 연구는 2016년 6월 16일부터 2016년 12월 31일까지 건강검진센터를 방문한 726명을 대상으로 Schirmer's 검사와 대사증후군 검사를 통해 전신적 만성 염증성 상태가 국소적 만성 염증성 상태로서의 안구건조증에 미치는 영향을 알아보고자 시행하였다. 대상자중 hs-CRP, HbA1c를 동시 측정한 214명을 대상으로 연구를 진행하였다. 연구대상자 중 고 연령일수록 (p<0.001), 성별로는 여성에서 유의하게 안구건조증이 증가하였으며(p=0.020), 공복혈당과 hs-CRP와는 연관이 없었다. 또한 HbA1c가 증가할수록 안구건조증에 대한 위험도가 증가하였다(β=1.960, p=0.025). 따라서 안구건조증은 만성 염증성 상태로 인한 눈물샘의 미세혈관 변화에 의한 것이 아니며 당뇨환자의 경우 단기간의 혈당 조절보다 장기간의 혈당 조절상태가 더욱 중요하게 작용할 수 있음을 알 수 있으며 당뇨병 환자에서 안구 건조증의 높은 유병률은 만성 염증으로 인한 미세 혈관 변화보다는 자율 기능 장애로 인한 것으로 생각된다.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.473-482
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• 2021

자동화된 운항 시스템 도입으로 항공안전은 크게 개선되었지만, 운항을 직접 담당하는 항공기 조종사에게는 새로운 도전이 생겼다. 항공운항 관점에서의 조종사의 스트레스를 Startle과 Surprise구분할 수 있다. Startle을 총소리 같이 갑작스럽거나 위협적인 자극에 대한 짧고 강한 생리적인 반응이며, Surprise는 자신의 예상을 빗나가는 예기치 못한 사건에 대한 인지-감정적 반응이다. Martin 등이 실시한 Startle 효과 실험(2012년)에서 조종사는 Startle 상태에서 반응 지연과 심박 수 증가 등 생리적인 반응을 확인하였고, Rahim의 Startle/Surprise 실험(2020년)에서 사전 계획된 비상조치훈련은 조종사의 호흡수와 맥박수의 변화가 없으나, 비계획된 상황과 항공기가 복잡할수록 호흡 수와 심박 수가 증가되었다는 사실을 확인하였다. 이 실험 결과를 바탕으로 국내 조종사 훈련에서도 기술적 능력을 전달에만 집중하는 것이 아닌 비기술적 능력에 대한 고려가 필요하며, 법령에 의한 기계획된 단순 반복적인 훈련 항목보다는 항공사의 상황을 고려한 비정형화된 다양한 비상조치 훈련의 도입이 필요하다고 하겠다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권1호
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• pp.28-33
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• 2016

배터리는 휴대폰, 전기자동차, 무인잠수정 등과 같은 분야에서는 주 동력원으로 사용되고, 일반 자동차에서는 시동기 또는 램프구동용으로 사용되며, 일반 선박에서는 비상전원으로 사용되고 있다. 2차 전지로는 납축전지와 리튬이온 배터리를 많이 사용하고 있으며, 납축전지는 가격이 비교적 저렴하고 안전하다. 리튬이온전지는 에너지 밀도가 높고 출력이 우수하며 수명이 긴 장점이 있으나 공기 중의 수분과 반응하여 폭발의 위험성을 가지고 있다. 그러나 최근에는 방수, 방염, 방진 기술의 발달에 힘입어 리튬배터리의 사용이 증가하고 있고, 특히 하이브리드 선박 및 전기추진 선박 등의 주동력원으로 사용될 만큼 그 사용범위가 점점 넓어지고 있으므로 좀 더 엄격한 배터리의 관리가 필요하다. 하이브리드 선박에서는 500kWh 이상의 대용량 동력원을 만들기 위하여 셀(Cell) 단위로 이루어진 수십 개의 리튬배터리가 들어 있는 팩들로 접속이 된 전원을 사용한다. 따라서 배터리 점검에 필요한 검출 전압, 전류 및 온도 데이터들을 관리용 서버로 보내 주는 유선 점검 및 감시시스템을 구현하는 데에는 많은 전선과 통신 모듈이 필요하다. 본 논문에서는 직렬통신 모듈보다 가격이 저렴하고 전선을 사용하지 않는 저 전력 블루투스(Bluetooth low energy, BLE) 무선통신 모듈과 전력선 모뎀을 사용하여 하이브리드 선박용 리튬배터리 저가형 점검 및 감시시스템을 구현하고자 한다. 배터리의 점검요소에는 잔존용량(State of charge, SOC)과 잔존수명(State of health, SOH)이 있으며, 제안한 시스템은 이들을 규칙적으로 점검하여 배터리의 수명 예측과 예방 정비를 할 수 있기 때문에 안전사고를 방지할 수 있을 것으로 전망된다.

• Geomechanics and Engineering
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• 제37권3호
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• pp.293-306
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• 2024

Influenced by the alternating effects of dynamic and static pressure during the mining process of close range coal seams, the surrounding rock support of cross mining roadway is difficult and the deformation mechanism is complex, which has become an important problem affecting the safe and efficient production of coal mines. The paper takes the inclined longwall mining of the 10304 working face of Zhongheng coal mine as the engineering background, analyzes the key strata fracture mechanism of the large inclined right-angle trapezoidal mining field, explores the stress distribution characteristics and transmission law of the surrounding rock of the roadway affected by the mining of the inclined coal seam, and proposes a segmented and hierarchical support method for the cross mining roadway affected by the mining of the close range coal seam group. The research results indicate that based on the derived expressions for shear and tensile fracture of key strata, the ultimate pushing distance and ultimate suspended area of a right angle trapezoidal mining area can be calculated and obtained. Within the cross mining section, along the horizontal direction of the coal wall of the working face, the peak shear stress is located near the middle of the boundary. The cracks on the floor of the cross mining roadway gradually develop in an elliptical funnel shape from the shallow to the deep. The dual coupling support system composed of active anchor rod support and passive U-shaped steel shed support proposed in this article achieves effective control of the stability of cross mining roadways, which achieves effective control of floor by coupling active support and preventive passive support to improve the strength of the surrounding rock itself. The research results are of great significance for guiding the layout, support control, and safe mining of cross mining roadways, and to some extent, can further enrich and improve the relevant theories of roof movement and control.

• Geomechanics and Engineering
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• 제29권6호
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• pp.697-706
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• 2022

In order to explore the stable anchoring conditions of coal side under the mining disturbance of soft section coal pillar in Wangcun Coal Mine of Chenghe Mining Area, the distribution model of the anchoring support pressure at the coal pillar side was established, using the strain-softening characteristics of the coal to study the distribution law of anchoring coal side support pressure. The analytical solution for the reinforcement anchorage stress in the coal pillar side was derived with the inelastic state mechanical model. The results show that the deformation angle of the roadway side and roof increases with the roof subsidence due to the mining influence at the adjacent working face, the plastic deformation zone extends to the depth of the coal side, and the increase of anchorage stress can effectively control the roof subsidence and further deterioration of plastic zone. The roadway height and the peak support pressure have a certain influence on the anchorage stress, the required anchorage stress of the coal side rises with the roadway height and the peak support pressure. The required anchorage stress of the coal pillar side decreases as the cohesion between the coal seam and the roof and floor and the anchor length increases. Then, applied the research result to Wangcun coal mine in Chenghe mining area, the design of anchor cable reinforcement support was proposed for the section of coal pillars side that has been anchored and deformed, which achieved great results and effectively controlled the convergence and deformation of the side, providing a safety guarantee for the roadway excavation and mining.

• Journal of Chest Surgery
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• 제28권5호
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• pp.453-463
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• 1995

During 42 month period 91 consecutive patient underwent coronary artery bypass surgery. The mean age of these patient was 57 years [range from 28 to 78 years . There were 57 men and 34 women. The preoperative risk factors that include beyond the 50 % of total patients were male sex, obesity, hypo-high-density lipoproteinemia, smoking, hypercholesterolemia, hyper-low-density lipoproteinemia, hypertriglyceridemia and hypertension. Preoperatively 27 patients had stable angina pectoris and 39 patients of unstable angina pectoris. Twenty five patients had previous myocardial infarction history. The patterns of disease were 8 patients of single vessel involvement, 18 patients of double vessel involvement, 54 patients of triple vessel involvement and 11 patients of left main coronary artery disease. Fifty five patients were in Canadian Cardiovascular Society functional class III. Myocardial revascularization was performed under emergency conditions in 5 patients. Nine percent of patients had previous PTCA history. We performed 16 cases of sequential anastomosis, internal mammary artery harvest in 86 percent of total patients and total 284 distal anastomoses[mean 3.1 anastomosis per patient . The mean ACC time was 60.5 minutes and ECC time was mean 110 minutes. The combined surgeries were 16 cases of endarterectomy, 2 cases of LV aneurysmectomy, 1 case of Bentall operation, 1 case of repair of sinus of Valsalva, 1 case of ligation of coronary AV fistula and 1 case of excision of breast mass. The most common complication was wound infection[12 cases, 13 % . There was one hospital death due to postoperative respiratory failure and low output syndrome in patient with postinfarction VSD, LV aneurysm. Postoperative 88 patients were in Functional class I or II. The 99mTc-MIBI myocardial perfusion scan that used as evaluation of postoperative state was well correlated with patient`s symptoms instead of some disadvantages.

• Steel and Composite Structures
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• 제35권5호
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• pp.641-657
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• 2020

A unique lightweight string truss deployable bridge assembled by thin-walled fiber reinforced polymer (FRP) and metal profiles was designed for emergency applications. As a new structure, investigations into the static structural performance under the serviceability limit state are desired for examining the structural integrity of the developed bridge when subjected to unsymmetrical loadings characterized by combined torsion and bending. In this study, a full-scale experimental inspection was conducted on a fabricated bridge, and the combined flexural-torsional behavior was examined in terms of displacement and strains. The experimental structure showed favorable strength and rigidity performances to function as deployable bridge under unsymmetrical loading conditions and should be designed in accordance with the stiffness criterion, the same as that under symmetrical loads. In addition, a finite element model (FEM) with a simple modeling process, which considered the multi segments of the FRP members and realistic nodal stiffness of the complex unique hybrid nodal joints, was constructed and compared against experiments, demonstrating good agreement. A FEM-based numerical analysis was thereafter performed to explore the effect of the change in elastic modulus of different FRP elements on the static deformation of the bridge. The results confirmed that the change in elastic modulus of different types of FRP element members caused remarkable differences on the bending and torsional stiffness of the hybrid bridge. The global stiffness of such a unique bridge can be significantly enhanced by redesigning the critical lower string pull bars using designable FRP profiles with high elastic modulus.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.19.1-19.7
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• 2015

Background: The purpose of this retrospective study was to investigate the usefulness of tracheostomy scoring system in the decision of postoperative airway management in oral cancer patients. Materials and methods: A total of 104 patients were reviewed in this retrospective study, who underwent radical resection with or without neck dissection and free flap reconstruction due to oral cancer. The patients were classified into three groups according to the timing of the extubation; extubated groups (n = 51), overnight intubation group (n = 45), and tracheostomy group (n = 8). Cameron's score was used to evaluate the relation between the state of the patient's airway and the type of the operation. Results: Tracheostomy was performed in eight patients (8/104, 7.7 %). A total of 22 patients (21.2 %) had more than 5 points of which 17 patients (77.3 %) did not have a tracheostomy and any postoperative emergency airway problems. The tracheostomy scores were significantly different among the three groups. Hospital stay showed a significant correlation with the tracheostomy score. Conclusions: The scoring system did not quite agree with the airway management of the authors' clinic; however, it can be one of the clinical factors predicting the degree of the postoperative airway obstruction and surgical aggressiveness for recovery. The further studies are needed for clinically more reliable scoring systems.

• 가족자원경영과 정책
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• 제16권3호
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• pp.153-176
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• 2012

This study gives an account of the state of baby-boomer households in regard to assets and liabilities utilizing the 2006 Household Asset Survey and the 2011 Survey of Household Finances. Using the data gathered from each year, this study examined the proportion of households who had each type of asset and liability, and the amount of them. This study also compared the amount of assets and liabilities of baby-boomer households with those of non baby-boomer households in 2006 and 2011 respectively. Finally, this study examined the amount of change and composition ratio of assets and liabilities of baby-boomer households between 2006 and 2011. Selected financial ratios were also presented for both years. Major findings are as follows. The average asset amount for baby-boomer households was approximately 296 million in 2006 and 392 million in 2011. Of total assets, 78% and 76.5% were real assets in 2006 and 2011 respectively. The average financial assets of 2006 baby-boomer households were approximately 66 thousand and the average amount of debt was 42 thousand. For 2011 baby-boomer households, the average amount of financial assets was 92 thousand and the average amount of debt was 73 thousand. Results from the 2011 survey showed that baby-boomer households had a significantly higher proportion of total assets, total debt, and net worth than non baby-boomer households. The proportion of savings, saving insurance, stocks, and mutual funds were significantly higher for baby-boomer households than non baby-boomer households in 2011. In regard to financial ratios, the emergency fund index and debt burden index were appropriate to the guidelines of asset quality, although the propensity to investment indexes were not.

• Journal of Acupuncture Research
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• 제26권5호
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• pp.171-181
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• 2009

Objectives : A ruptured disc is a condition in which part or all of the nucleus pulposus is forced through a weakened part of the disc, resulting in back pain and leg pain caused by nerve root irritation. In this report, we investigated the effect of oriental medicine treatment in parallel with sling exercise therapy on ruptured intervertebral lumbar disc patients. Methods : The patients who have ruptured disc were treated by oriental medicine treatment in parallel with sling exercise therapy. The patients' symptoms were assessed by visual analogue scale(VAS) and revised oswestry disability questionnaire(RODQ) every week. Results : In all cases, chief complain such as lumbago, radicular pain and paresthesia were improved after above treatment. VAS score and RODQ score of all cases were decreased. Conclusions : There were usually thought to need operation in ruptured disc. But conservative treatment such as oriental medicine treatment in parallel with sling exercise therapy is helpful to improve the symptoms of the ruptured intervertebral lumbar disc except the emergency state.