• Journal of Chest Surgery
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• 제22권5호
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• pp.816-822
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• 1989

Aneurysms of the descending thoracic aorta can be caused by various etiologies. So, its abrupt rupture leads life-threatening state, it must be operated as soon as possible. Surgical treatment of the descending thoracic aortic aneurysm requires temporary cross-clamping of major artery. The obligatory occlusion of the descending thoracic aorta during management causes proximal arterial hypertension and distal arterial hypotension. The former may leads to left ventricular failure, or cerebrovascular accident, whereas the latter may leads to spinal cord ischemia or renal injury. Some have recommended insertion of temporary shunt around the occluded descending aorta to prevent above problems. Still others would favor expeditious operation employing simple aortic occlusion during the repair of the descending aorta. Recently we had experienced two cases of dissecting aneurysms of descending thoracic aorta which performed aortoplasty with Gore-Tex conduit under simple aortic occlusion. The one was 34-year-old female patient with traumatic dissecting aortic aneurysm [5 em X 5 cm] on the descending thoracic aorta distal to the origin of the left subclavian artery and the other was 58-year-old female patient with atherosclerotic dissecting descending thoracic aortic aneurysm [6 cmX7 cm] and diffuse abdominal aortic aneurysms [3X5 cm]. Both patients performed standard left posterolateral thoracotomy. After the aneurysmal sac was mobilized, occluding vascular clamps were placed on the transverse aorta proximal to the origin of the left subclavian artery, and on the distal descending aorta without adjuvant bypass procedures for 31 and 32 minutes, respectively, and the aneurysmal sac was repaired with 18 mm ringed Gore-Tex conduit graft. Both patients postoperative courses were uneventful.

• 한국임상수의학회지
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• 제34권1호
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• pp.1-6
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• 2017

Heartworm disease (HWD) in dogs is a life-threatening mosquito-borne disease resulting in right-sided congestive heart failure and inflammatory pulmonary disease. Due to complications from adulticidal therapy with melarsomine, slow kill protocol either with preventive dose of ivermectin or combined with doxycycline has been proposed for an alternative adultcidal therapy in dogs with HWD. Therefore, this study evaluated the clinical outcome of adultcidal therapy in dogs with class II stage of HWD after treating either American Heartworm Society (AHS) or slow kill protocol for 10 months. Clinical outcome after therapy was evaluated by clinical, radiographic and echocardiographic examination along with hematology before (D0) and after therapy (D300). Although clinical signs associated with HWD were all resolved after therapy in both groups, the infection was not cleared out 67% of dogs treated by slow kill protocol at the end of therapy. Furthermore, pulmonary arterial flow of acceleration time to ejection time ratio (AT/ET) and the right pulmonary artery distensibility index (RPADI) have been firstly used for detecting pulmonary hypertension in this study group. The pulmonary hypertension was more common in dogs with mild clinical signs, although tricuspid and pulmonary regurgitation were not detectable in most dogs in this study. Our study findings suggested that the slow kill protocol might not be efficacious enough to clear out HWD in dogs and more attention on the presence of pulmonary hypertension might be necessary for effective management of HWD in dogs.

• 한국안전학회지
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• 제34권5호
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• pp.7-14
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• 2019

The type III vessel, which is used to store high-pressure hydrogen gas, is made by wrapping the vessel's liner with carbon fiber composite materials for strength performance and lightening. The liner seals the internal gas and the composite resists the internal pressure. The properties of the fiber composite material depends on the angle and thickness of the fiber. Thus, engineers should consider these various design variables. However, it significantly increases the design cost due to the trial and error under designing based on experience or experiments. And, for aluminum liners, fatigue loads due to using and charging could give a huge impact on the performance of the structure. However, fatigue failure does not necessarily occur in the position under the highest load in use. Therefore, for hydrogen storage vessel, fatigue evaluation according to design patterns is essential because stress distribution varies depend on composite layer patterns. This study performed an optimization analysis and evaluated a high-pressure hydrogen storage vessel to minimize these trial and error and improve the reliability of the structure, while simultaneously conducting fatigue assessment of all patterns derived from the optimization analysis process. The results of this study are thought to be useful in the strength improvement and life design of composite reinforced high-pressure storage vessels.

• 한국기계가공학회지
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• 제18권9호
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• pp.29-35
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• 2019

The structure of the machinery industry due to the 4th industrial revolution is changing from precision and durability to intelligent and smart machinery through sensing and interconnection(IoT). There is a growing need for research on prognostics and health management(PHM) that can prevent abnormalities in processing machines and accurately predict and diagnose conditions. PHM is a technology that monitors the condition of a mechanical system, diagnoses signs of failure, and predicts the remaining life of the object. In this study, the vibration generated during machining is measured and a classification algorithm for normal and fault signals is developed. Arbitrary fault signal is collected by changing the conditions of un stable supply cutting oil and fixing jig. The signal processing is performed to apply the measured signal to the learning model. The sampling rate is changed for high speed operation and performed machine learning using raw signal without FFT. The fault classification algorithm for 1D convolution neural network composed of 2 convolution layers is developed.

• Earthquakes and Structures
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• 제17권5호
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• pp.511-519
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• 2019

The concrete gravity dam is one of the most important parts of the nation's infrastructure. Besides the benefits, the dam also has some potentially catastrophic disasters related to the life of citizens directly. During the lifetime of service, some degradations in a dam may occur as consequences of operating conditions, environmental aspects and deterioration in materials from natural causes, especially from dynamic loads. Cumulative Absolute Velocity (CAV) plays a key role to assess the operational condition of a structure under seismic hazard. In previous researches, CAV is normally used in Nuclear Power Plant (NPP) fields, but there are no particular criteria or studies that have been made on dam structure. This paper presents a method to calculate the limitation of CAV for the Bohyeonsan Dam in Korea, where the critical Peak Ground Acceleration (PGA) is estimated from twelve sets of selected earthquakes based on High Confidence of Low Probability of Failure (HCLPF). HCLPF point denotes 5% damage probability with 95% confidence level in the fragility curve, and the corresponding PGA expresses the crucial acceleration of this dam. For determining the status of the dam, a 2D finite element model is simulated by ABAQUS. At first, the dam's parameters are optimized by the Minitab tool using the method of Central Composite Design (CCD) for increasing model reliability. Then the Response Surface Methodology (RSM) is used for updating the model and the optimization is implemented from the selected model parameters. Finally, the recorded response of the concrete gravity dam is compared against the results obtained from solving the numerical model for identifying the physical condition of the structure.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.554-559
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• 2006

The currently common housing is obviously going to be under the reconstruction in just $20{\sim}30$ years, with the failure to satisfy the improvement of national income, diversification and advance of national demand. But, reckless and random reconstruction Induce the serious problem of environmental pollution involving the loss of national treasury and excess materials of constructions. In order to address such problem, the common housing of longevity, which can adequately cope with the changes of times and tastes of inhabiters, in the future, is arising as an alternative. Recently, the groundbreaking phase of common housing is also being considered as another alternative to resolve such problem. The common housing of longevity has an advantage to create a free and comfortable space in accordance with the tastes of inhabiters, as well as expanding the durability of building. But, the current facility system has an inability to deal with the sort of housing. Thus, the research paper is designed to make an analysis on problems of common housing in South Korea, which has made it difficult to handle a changing space, and based on the analysis, the paper is intended to make a review on the future-oriented facility service appropriate enough to deal with the changing aspects of space.

• 대한임베디드공학회논문지
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• 제16권6호
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• pp.267-276
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• 2021

The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

• 품질경영학회지
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• 제49권3호
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• pp.269-279
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• 2021

Purpose: The purpose of this study was to suggest weapon system specifications for requirements of Condition-Based Maintenance(CBM/CBM⁺). Methods: The military documents and case studies with regard to condition-based maintenance were reviewed. Representative Korea defense specifications of weapon system such as an aircraft, a C4ISR etc. were analyzed and investigated the level of requirement for maintainability was. Results: Condition-based maintenance was defined in both U.S. instruction and Korean directive. While deparment of defense(U.S.) provide a guidebook for CBM⁺, detailed instruction was not sufficient for Korean. Ministry of national defense(ROK) define the CBM⁺ by means of IPS element which should be developed along with the system development. The maintainability was barely included in Korean defense specifications, except for BIT(Built-in test) function. As a first step for defining the condition-based maintenance requirement in defense specification, this study suggests a standard form for data needed to acquire according to types of system, fault, failure, and so on. Conclusion: The empirical researches on CMB/CBM⁺ with domestic weapon systems are not enough, and a logic which leads the maintenance strategy to CMB/CBM⁺ is not solved. Through technical researches and institutional improvements including this study, we hope that condition-based maintenance would be fully established in the Korean defense field.

• 비교문화연구
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• 제42권
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• pp.23-46
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• 2016

이 글에서는 식민지 근대 조선의 영토 내에서 존재하였던 헤테로토피아적 공간에 주목하였다. 근대 질서에서 보기에는 이질적이나 당대 사회의 희망을 구현했던 헤테로토피아를 찾아서, 그 공간들이 가졌던 실제적 특징을 파악하였다. 또한 이런 헤테로토피아적 공간을 식민지 근대 지식인들이 담론화하는 방식을 살펴보며, 근대적 지배 체제에 대한 당대의 또 다른 시각을 알아보았다. 삼일독립운동이 시작되었던 탑동공원과 정신병동인 동팔호실은 근대적 관점에서 가장 이질적이면서도 그로테스크한 공간이었다. 그곳은 근대성이 실패한 공간들로 표상되었다. 하지만 이 공간 속에서는 독립에 대한 발화가 공공연하게 이루어졌으며, 이는 이 공간들이 당대 사회의 희망을 담아내는 유토피아로 기능하게 하였다. 그렇지만 당대의 지배 체제는 이 공간 속에서 이루어지는 발화를 괴담으로 간주하며 폄하했다. 원인을 알 수 없는 이야기인 괴담은 근대의 지식 체계 그리고 이를 바탕으로 한 당대의 지배 체제가 불완전함을 드러내었다. 체제의 불완전함은 일상에 대한 불안을 야기하였다. 이처럼 이 글에서는 헤테로토피아를 괴담으로 왜곡하여 전달하였던 담론화의 방식을 통해 식민지 근대의 질서가 가지고 있던 불안의 한 측면을 살펴보았다.

• 한국자원공학회지
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• 제55권6호
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• pp.546-552
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• 2018

금번 6차 광해방지 국제심포지움 발표사례로 볼 때, 국가별 광산개발의 역사, 지리여건, 경제상황 등이 상이하나, 과거 개발된 광산으로 인해 발생한 산성광산배수로 인한 수질오염, 광물찌꺼기 유실로 인한 토양오염 및 수질오염, 사면파괴로 인한 산사태, 지하갱도 붕괴로 인한 지반침하 등으로 인간의 생활이 위협당하고 있다. 나라별로 기술력과 법제도의 차이가 있고, 광해복구가 진행 중인 나라와 이제 시작하려고 제도마련 및 기술지원을 받아야 하는 나라도 있다. 광해복구를 시작하려는 나라에서는 국제사회에 도움을 요청하고 있어 기술적 제도적으로 앞선 선진국에서는 복구를 시작하려는 나라와 공조를 통해 광해를 복구해야할 필요가 있다.