• 한국생산제조학회지
• /
• 제21권3호
• /
• pp.479-486
• /
• 2012

This paper presents a high-speed automatic micro-alignment system that is a part of an inspection machine for small-sized molded lenses of mobile phones, palm-top computers, and so on. This work was motivated by the shortcomings of existing highest-grade commercial machine. A simple tip/tilt/Z parallel mechanism is designed based on kinematic couplings, which is a 3-degree-of-freedom (3-DOF) moderate-cost alignment stage. It is used to automatically adjust the posture of each lens on the tray, which is impossible by the conventional instrument. Amplified piezoelectric actuators are used to ensure the accuracy and dynamic response. Forward kinematic analysis and simulation show that the parasitic motion is small enough compared to the actuator stroke. From the workspace analysis of the moving platform, it is clear that the output motion range satisfies the design requirements.

• 한국측량학회지
• /
• 제9권2호
• /
• pp.9-18
• /
• 1991

현재의 교통사고 조사에서 첨부되는 사고 현장의 조사 내용은 현장에서 작성된 현장 상황 스케치와 소요점간을 줄자로 측정하는 것이 대부분이다. 이러한 처리 방법은 대형화 되어가고 복잡해지는 교통사고의 처리에 한계가 제기되고 있다. 본 연구에서는 이러한 문제의 해결을 모색하기 위해 사진 측량의 방법을 도입하여 교통사고 현장의 필요점간의 정확한 3차원 측정 및 정밀도화를 수행하였다. 사진 측량의 효과로는 신속한 현장조사, 교통체증의 조기해소, 사고 현장의 연쇄 사고의 방지 등이 있다. 본 연구에서 이용한 준측량용 카메라와 3차원 사진측량 시스템은 기준점 측량이 필요없이 간단한 조작과 경제적으로 이용 가능하기 때문에 경찰에서의 교통사고 조사 및 증거자료 확보 등의 다양한 분야에 걸쳐 매우 유용할 것으로 사료된다.

• 전기학회논문지P
• /
• 제55권4호
• /
• pp.196-201
• /
• 2006

A electrical fault that may generate an electrical disaster is defined as any abnormal condition caused by reduction in the insulation strength. To find out the abnormal condition, periodical inspections have being performed every 3 years. Recently, the number of empty houses during normal working hours is rising by dramatic increase in the number of nuclear families and double income families. To define the potential risk of the electric installation, measurement of zero phase current has been being considered. But the measured value could not be adapted to an absolute reference to the installation because the measured zero phase current value also contained capacitive leakage current. Therefore, in this paper, the correlation between the condition of the electrical installation and the zero phase current was analyzed. The result focuses on to detect them in a cost efficient way.

• 한국통신학회논문지
• /
• 제35권7C호
• /
• pp.634-641
• /
• 2010

말기신부전의 경우 당뇨병, 고혈압 등의 4대 사망 요인의 합병증으로 이로 인한 의료비 지출과 삶의 질의 저하가 큰 사회적 문제로 작용하고 있다. 신장의 경우 이상이 생겨도 자각증상이 거의 없기 때문에 진단이 어렵고 질환 발병시 완치 및 기능회복이 어렵기 때문에 예방 및 조기 진단이 매우 중요하다. 본 논문은 신장 기능의 이상 여부를 측정하는 하나의 방법으로 한의학의 망진법에서 진단의 지표가 되는 색윤을 활용하고자 한다. 안면 영상에서의 반사도 즉 색윤의 변화와 신장 기능과의 상관성을 분석하기 위해 편광필터를 사용하여 색윤을 측정하는 방법을 제안하고 이를 통한 실험을 진행하였다.

• 설비공학논문집
• /
• 제27권2호
• /
• pp.103-111
• /
• 2015

In general, no particularly well-established standards have been in place so far, for the method of evaluating the deteriorated level of pipes and ducts of industrial facilities. For that reason, the evaluation depends upon various studies which are based on the analysis of the residual life, thickness thinning, closure rate, and scale thickness that measure a few specific positions of pipes. It also depends upon the expertise in business operation and the specific techniques conducted by the inspection companies and institutions. This research introduces the concept of measuring units per section and the selection method of measurement points per section. Furthermore, specific methodologies were developed to plan and analyze deterioration level of industrial pipes and ducts by engineers and managers using a section map. Consequently, applying the outcomes from this study to the plant equipment of the incineration facility resulted in saving 42% of the repairing and remodeling cost.

• 산업경영시스템학회지
• /
• 제37권4호
• /
• pp.231-238
• /
• 2014

Optimum lot size calculation for real world manufacturing environment has been focused since last few decades. Several extensions have been made to the basic economic order and production order quantity models to realize the possible practical situations in industry. However, focus on work-in-process inventory has been ignored relatively. This paper provides a comprehensive review of the models developed for group technology based manufacturing environment focusing on work-in-process inventory. Models have been extended from a perfect manufacturing conditions to an imperfect manufacturing situation considering rework, rejection and inspection. Optimum lot size has been evaluated using a simple algebraic optimization approach. Significant parameters are highlighted using sensitivity analysis for the developed models. Numerical example is used to illustrate the utilization of such models in day-to-day production setups and the impact of significant factors' variation on total cost and optimum lot size.

• Earthquakes and Structures
• /
• 제7권5호
• /
• pp.609-626
• /
• 2014

The capabilities of a high-resolution Digital Image Correlation (DIC) system are presented within the context of deformation measurements of full-scale concrete columns tested under reversed cyclic loading. The system was developed to have very high-resolution such that material strains on the order of the cracking stain of concrete could be measured on the surface of full-scale structural members. The high-resolution DIC system allows the measurement of a wide range of deformations and strains that could only be inferred or assumed previously. The DIC system is able to resolve the full profiles of member curvatures, rotations, plasticity spread, shear deformations, and bar-slip induced rotations. The system allows for automatic and objective measurement of crack widths and other damage indices that are indicative of cumulated damage and required repair time and cost. DIC damage measures contrast prevailing proxy damage indices based on member force-deformation data and subjective damage measures obtained using visual inspection. Data derived from high-resolution DIC systems is shown to be of great use in advancing the state of behavioral knowledge, calibrating behavioral and analytical models, and improving simulation accuracy.

• 전자공학회논문지 IE
• /
• 제48권1호
• /
• pp.16-24
• /
• 2011

본 논문에서는 트림 T형 용접너트 생산 시스템 중 불량품을 자동으로 선별할 수 있는 자동 선별기를 비전 검사기를 사용하여 개발하였다. 카메라로부터 입력되는 영상 신호에 대해 히스토그램을 활용한 경계 판별 및 나사산 검출, 이진 모폴로지 연산(Binary morphology operation)을 활용한 얼룩 검출 등의 기법을 활용하였다. 기존의 검사기나 육안 검사에서 불가능하였던 수치 검사를 0.1mm의 정밀도로 검사할 수 있도록 하였으며, 이를 통해 제조단가를 25% 절감하고 생산성을 330% 이상 향상시킬 수 있었다.

• 토지주택연구
• /
• 제11권3호
• /
• pp.83-92
• /
• 2020

In South Korea, problems caused by material deterioration of time-worn concrete structures have been increased recently. Because severe material deterioration could damage the structure's safety, it's important to evaluate the old structure's condition and structural capacity regularly to keep its proper performance. The safety evaluation of concrete structures has been initiated and performed periodically since 1995 according to a guideline in accordance with a law in Korea. The guideline prescribes the evaluation types, intervals and methods of the target structure. A lot of cost and labor have been invested every year to carry out the regular safety evaluation. However, it's not clear that the current manual could inspect the old structure's condition and assess the structural capacity precisely. Thus, the verification study initiated to figure out the Korean safety evaluation manual's practicalness. First, the Korean manual was analyzed and then compared with that of other countries for concrete bridges which are representative concrete structure. After that, the previously written evaluation reports were collected and analyzed to find out how the safety evaluation has been carried out. Based on the study results, the parts requiring verification of the manual were drawn. A research program is in progress in order to verify the parts by performing tests with actual structural members from decommissioned concrete bridges.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
• /
• pp.99-102
• /
• 2007

Infrared thermography is one of the most valuable and cost-effective diagnostic techniques for predictive maintenance on electrical systems. For the installations, the thermography can identify major problems, which if left unattended could lead to breakdowns. The result thermal images depend upon operator skills, inspection technique, and weather conditions. When the thermographer is applied to remote monitoring, the conditions of the systems are not perfectly analyzed because operators are hard to know the weather effects of the installed place. Therefore, this paper defines the effect by weather conditions these factors will influence the final results. The purpose of this paper is to define the weather effects that a thermographer needs to consider for successful condition analysis.