• 한국CDE학회논문집
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• 제15권5호
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• pp.354-361
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• 2010

The paper presents an efficient computation of optimal tool length for 5-axis mold & die machining. The implemented procedure processes an NC file as an initial input, where the NC data is generated by another commercial CAM system. A commercial CAM system generates 5-axis machining NC data which, in its own way, is optimal based on pre-defined machining condition such as tool-path pattern, tool-axis control via inclination angles, etc. The proper tool-length should also be provided. The tool-length should be as small as possible in order to enhance machinability as well as surface finish. A feasible tool-length at each NC block can be obtained by checking interference between workpiece and tool components, usually when the tool-axis is not modified at this stage for most CAM systems. Then the minimum feasible tool-length for an NC file consisting of N blocks is the maximum of N tool-length values. However, it can be noted that slight modification of tool-axis at each block may reduce the minimum feasible tool-length in mold & die machining. This approach can effectively be applied in machining feature regions such as steep wall or deep cavity. It has been implemented and is used at a molding die manufacturing company in Korea.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2433-2452
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• 2017

Recently, the pipeline-forwarding has been proposed as a new technique to resolve the end-to-end latency problem of the duty-cycle MAC protocols in Wireless Sensor Networks (WSNs). Some protocols based on this technique such as PMAC and PRI-MAC have shown an improvement not only in terms of reducing end-to-end latency but also in terms of reducing power consumption. In these protocols, however, the sensor nodes still waste a significant amount of energy for unnecessary idle listening during contention period of upstream nodes to check the channel activity. This paper proposes a new pipeline-forwarding duty-cycle MAC protocol, named RP-MAC (Reduced Pipelined duty-cycle MAC), which tries to reduce the waste of energy. By taking advantage of ACK mechanism and shortening the handshaking procedure, RP-MAC minimizes the time for checking the channel and therefore reduces the energy consumption due to unnecessary idle listening. When comparing RP-MAC with the existing solution PRI-MAC and RMAC, our QualNet-based simulation results show a significant improvement in term of energy consumption.

• 전자통신동향분석
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• 제32권6호
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• pp.105-115
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• 2017

This paper describes a project - based quality management model that identifies development technologies and codes while at the same time verifying the ability to implement processes that are essential in R & D projects. In order to verify the process implemented in the R & D project implementation, there are review, checking points, and evaluating methods the process performance levels for five processes such as defining requirements which is the beginning stage of system development, testing process which is the completion stage of system development, and project management and peer review process for project management and support in the proposed project-based quality management model. For development technology and code validation, the model included the documented test cases for each requirement by the developer in the requirements definition stage, debugging and testing in the design and implementation stages, static analysis and open source licence verification procedure, and system environment. After applying the model in SW development R&D project for evaluating the process performance, and verifying the development technology and the code, the developers responded that the improvement in the development technique and the code, and upgrade of process performance level for project are more than 10%.

• 척추신경추나의학회지
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• 제4권1호
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• pp.7-17
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• 2009

Objectives: The objective of this study is to report the effectiveness of Chuna treatment and burning acupuncture therapy on shoulder impingement syndrome. Methods: Among the patients with shoulder pain, We selected 3 patients diagnosed as shoulder impingement syndrome by physical examination and magnetic resonance imaging(MRI). After Chuna treatment and burning acupuncture therapy, we evaluated the effectiveness by measuring range of movement(ROM) and checking The Shoulder Pain And Disability Index(SPADI) every three times the patients called at the clinic for three weeks. Results: The symptoms of the patients got improved relatively in short period considering shoulder impingement syndrome belongs to chronic diseases and steps chronical procedure in recovering. Conclusions: These cases showed Chuna treatment and burning acupuncture therapy could be applied on shoulder impingement syndrome and were effective for improving the symptoms. We suggest that further studies and clinical trials will be needed afterwards.

• International Journal of CAD/CAM
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• 제7권1호
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• pp.51-60
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• 2007

This paper presents an algorithm of optimal cutting tool selection for machining of the point-based surface that is defined by a set of surface points rather than parametric polynomial surface equations. As the ball-end and fillet-end mills are generally used for finish machining in a 3-axis computer numerical control machine, the algorithm is applicable for both cutters. The optimum tool would be as large as possible in terms of the cutter radius and/or corner radius which maximise (s) the material removal rate (i.e., minimise (s) the machining time), while still being able to machine the entire point-based surface without gouging any surface point. The gouging are two types: local and global. In this paper, the distance between the cutter bottom and surface points is used to check the local gouging whereas the shortest distance between the surface points and cutter axis is effectively used to check the global gouging. The selection procedure begins with a cutter from the tool library, which has the largest cutter radius and/or corner radius, and then adequacy of the point-density is checked to limit the accuracy of the cutter selection for the point-based surface within tolerance prior to the gouge checking. When the entire surface is gouge-free with a chosen cutting tool then the tool becomes the optimum cutting tool for a list of cutters available in the tool library. The effectiveness of the algorithm is demonstrated considering two examples.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.425-430
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• 2007

건설산업에서 폐기물 관리는 환경적${\cdot}$경제적 측면에서 중대한 영향을 미침에도 불구하고, 건설폐기물 관련 통계자료에 의하면 국내 건설폐기물 관리 수준이 상대적으로 낮음을 알 수 있다. 이에 따라 본 연구는 건설폐기물 관리의 요체인 건설폐기물 관리 지침을 고찰하여 문제점을 분석하고, 효과적인 폐기물 관리를 유도하는데 적합한 건설폐기물 관리 지침 개선 방향을 제시하고자 한다. 국내 기존 건설폐기물 관리 지침을 분석한 결과, 폐기물 관리의 목적이 총체적으로 법적인 기준을 벗어나지 않도록 관리하는 데 초점이 맞추어져 있음으로 인해 분석 기준인 "계획, 실행 및 운영, 점검 및 시정조치" 측면에서 효과적인 폐기물 관리 지침으로서의 역할을 다하고 있지 않음을 파악하였다. 또한, 문제점 분석 결과를 기반으로 "계획, 실행 및 운영, 점검 및 시정조치" 측면에서 국내 건설폐기물 관리 지침의 개선 방향을 제시하였다.

• 한국응급구조학회지
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• 제19권3호
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• pp.87-101
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• 2015

Purpose: The purpose of this study was to provide an appropriate direction for an effective field practice program by analyzing the factors related to practical procedures in the ambulance ride practice of paramedic students in Korea. Methods: Questionnaires were answered by 202 paramedic students from March 28 to April 15, 2014. The collected data were analyzed with SPSS WIN 18.0 program. Results: The general level of procedural exposure during ambulance ride practice was 59.0% on average. Considering the practice of specific areas, vital sign checking, patient assessment, and oxygen supply showed relatively high percentages of 92.3%, 77.4% and 72.6%, respectively, whereas the areas of fluid and drug, airway, and cardiopulmonary resuscitation recorded relatively low percentage of 25.8%, 24.1% and 50.2%, respectively. The level of direct practice was significantly high in the group that included the largest number of paramedics. Conclusion: For an effective field practice, the place of practice needs to have various cases of patients to ensure a wide experience of procedures during the practice, and ambulance workers with a high level of expertise should be selected to ride with students.

• 한국추진공학회지
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• 제26권1호
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• pp.77-87
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• 2022

한국항공우주연구원 스크램제트 엔진 시험설비를 활용한 스크램제트 엔진 흡입구 지상 시험을 수행하기 위하여 일반적으로 진행하는 시험 가능 여부 확인 절차를 소개하였다. 스크램제트 흡입구 시험을 수행하기 위하여 새롭게 제작된 마하 5 노즐의 설계 과정을 정리하였으며, 노즐의 코어 유동 분포를 확인하기 위한 장치를 설명하고 코어 유동 시험 분석 결과를 기록하였다. 일련의 시험 결과를 통하여 흡입구가 신규 마하 5 노즐 코어에 위치하는 것을 확인하였다.

• 대한두개안면성형외과학회지
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• 제23권6호
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• pp.269-273
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• 2022

Naso-orbito-ethmoidal (NOE) fractures are complicated fractures of the mid-face. The treatment of NOE fractures is challenging and a comprehensive treatment strategy is required. We introduce a case of NOE fracture treated with open reduction and suspension sutures. A 28-year-old woman presented with a unilateral NOE fracture. To reduce the frontal process of the maxilla, a suspension suture was made by pulling the fragment using a double arm suture via a transcaruncular incision. The suture thread was placed in the horizontal plane. Another suspension suture on the inferior orbital rim assisted reduction procedure, and they passed through the overlying skin. The reduction alignment could be finely adjusted by tightening the transcutaneous suture threads while checking the degree of bone alignment through the subciliary incision. The two suture threads were suspended using a thermoplastic nasal splint. An additional skin incision on the medial canthal area, which would have resulted in a scar, could be avoided. Four months postoperatively, computed tomography showed an accurate and stable reduction. The patient was satisfied with her aesthetic appearance, and functional deficits were not present.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.13-22
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• 2020

Reinforcement steel fixing is a skilled and manually intensive construction trade. Current practice for the quality assessment of reinforcement steel fixing is normally performed by fabricators and has high potential in having errors due to the tedious nature of the work. In order to overcome the current inspection limitation, this study presents an approach that provides visual assistance and inspection enhancement for inspectors to assess the dimensional layout of reinforcement steel fixing. To this end, this study aims to establish an end-to-end framework for rebar layout quality inspection using laser scanning and Augmented Reality (AR). The proposed framework is composed of three parts: (1) the laser-scanned rebar data processing; (2) the rebar inspection procedure integrating with AR; and (3) the checking and fixing the rebar layout through AR visualization. In order to investigate the feasibility of the proposed framework, a case study assessing the rebar layout of a lab-scaled formwork containing two rebar layers is conducted. The results of the case studies demonstrate that the proposed approach using laser scanning and AR has the potential to produce an intuitive and accurate quality assessment for the rebar layout.