• 전력전자학회논문지
• /
• 제13권1호
• /
• pp.33-40
• /
• 2008

본 논문은 단상 스위치드 릴럭턴스 모터의 역기전력 분석을 통해 회전자 위치를 추정하여 구동하는 센서리스 구동법을 제안한다. SRM은 회전자 위치에 따라 적정 고정자 권선을 여과시킴으로써 회전력을 발생하기 때문에 회전자 위치 정보가 필수적으로 요구된다. 회전자의 위치를 검출하기 위하여 다양한 회전자 위치센서를 사용하고 있으나 대부분의 위치 센서들은 모터의 부피와 구축비용을 증가시킬 뿐만 아니라 환경에 따라 구동시스템의 신뢰도를 저하시키는 경향이 있다. 따라서 본 논문에서는 이러한 문제들을 해결하기 위해 역기전력을 이용한 방법을 제안한다. 회전자와 고정자가 겹쳐지는 순간(overlap point) 역기전력이 급격하게 변화하게 되는 지점을 검출하여 회전자의 위치를 추정할 수 있으며, 속도 계산을 통해 적절한 위치에서 스위치를 온, 오프하여 SRM을 구동하게 된다. 본 연구에서 제안한 방식을 시뮬레이션과 실험을 통해 그 타당성을 검증하였다.

• 전자공학회논문지S
• /
• 제35S권2호
• /
• pp.137-145
• /
• 1998

In this paper, we propose a tube-hole center detection vision algorithm verifying the position of a tele-controlled robot and providing visual information for increasing reliability and efficiency in the diagnosis of steam generator (SG) tubes in nuclear power plant. A tele-controlled robot plays a role in carrying the probe used in inspecting the integrity of SG tubes. Thus accurately locating a tele-controlled robot on the desired tube-hole center is important issue for reliability of inspection. To do this work, we have to find the tube-hole center locations from the input image. At first, we apply the three-class segmentation method modified for this application. WE extract minimum bounding rectangles (MBRs) in the theresholded binary image. Second, for discriminating between MBR by tube and MBR by noise, we introduce the MBR rejection rules as knowledge-based rule set. MBRs are divided into the very dark region MBRs and the very bright region MBRs. In order to describe the region of complete tube-hole, the MBRs need a process of pairing each other. We then can find the tube-hole center from the paired MBR. For more accurately finding the tube-hole center in several sequential images, the centers of some frames need to be averaged. We tested the performance of our method using hundreds of real images.

• 천문학논총
• /
• 제32권1호
• /
• pp.17-19
• /
• 2017

The first version of the AKARI far-infrared All-Sky Bright Source Catalogue (BSC ver.1) was released to public in March 2010. It has been widely used for various astrophysical researches. We are continuing efforts to produce the next edition. The new version is expected to be improved in accuracy and reliability, as well as its volume. Many improvements to the next version are in progress. The time-line signal is being re-examined throughout the entire data processing. Correction processes for signal linearity and detector responsivity, and procedure for masking signal anomaly are revised. The source extraction process is further tuned and operating parameters will be optimized. These bring better reliability of the source detection and possibly an increase of source numbers. The position accuracy is expected to be improved. Systematic position error seen around the Galactic plane will also be corrected. We also plan to deliver the Faint Source Catalogue version 1.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1450-1454
• /
• 1996

Even though digital control type high speed solenoid valve is a little inferior to analog control type servo valve and proportional control valve in performance, it is cheap and has secure performance against pollutant and simple control circuit. But high speed solenoid valve is hardly used for heavy machinery instead of servo valve or proportional control valve that is used in severe condition because the valve itself is small capacity and it shows wide dead zone during on-off control and chattering of hydraulic cylinder by chattering of pressure. It is desirable to use low-priced and strong pollutant resistant high speed solenoid valve for obtaining reliability of operation from severe working condition because it isn't necessary to acquire response characteristic of high frequency when we consider the characteristic of heavy machinery operation. In this study, PWM control algorithm for pilot pressure control of large capacity pilot operating valve will be used for precision position control of heavy machinery hydraulic cylinder. Not only cost reduction of main control valve but also high reliability of heavy machinery in severe condition can be obtained by using this pilot operating spool valve with high speed solenoid valve.

• 복식
• /
• 제58권9호
• /
• pp.99-113
• /
• 2008

This paper provides the foundation to settle the new paradigm in the beauty industry service quality by confirming the beauty industry service quality influence on customer satisfaction and loyalty through the actual verification. The scale of this study for measurement of beauty industry service quality is confirmed through the certification of reliability and feasibility with questionnaire investigation after confirmation of contents and preliminary feasibility. The dimensions and items for measurement of beauty industry service quality are selected with service ability(6), tangible(4), responsiveness(3), reliability(2), conveniency(2). And it is confirmed that the level of service quality is changing unlike a beauty-shop facility or cost recognized traditionally as a key factor to occupy the higher position in competition of beauty-shops. This thesis presents the important point of current issue about kinds of strategy which beauty industry should establish in providing the beauty industry service for occupying higher position in keen competition.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
• /
• pp.117-122
• /
• 2006

Modernized GNSS such as new GPS signals updated GLONASS and coming Galileo promises higher quality and higher reliability for users. Powerful technologies such as Internet, ubiquitous network technology and sensor network has been used to promote a safe and more secure lifestyle. This report describes experimental trials to combine these technologies namely GPS and Sensor Network into a high-performance system. GPS is used to enlarge the communication range, resolving the service area limitations, as a wider service area is required at shore areas compared to urban area. GPS position datum is also used as primary network routing information to get practical Sensor Network. Another application is the under water Sensor Network. Accurate GPS position and time are used to establish stable and high reliability underwater acoustic Sensor Network. This paper describes the background of the project 'Harbor area Marine Ubiquitous Sensor Network', preliminary consideration and testing. Radio and acoustic communication is the main focus of this preliminary experiment.

• Journal of Korean Neurosurgical Society
• /
• 제63권4호
• /
• pp.504-512
• /
• 2020

Objective : An important factor during pituitary adenoma surgery is to preserve pituitary stalk (PS) as this plays a role in reduction of the risk of postoperative diabetes insipidus. The hypothalamic-hypophyseal tract (HHT) projects through the PS to the posterior pituitary gland. To reconstruct white matter fiber pathways, methods like diffusion tensor imaging (DTI) tractography have been widely used. In this report we attempted to predict the position of PS using DTI tractography and to assess its intraoperative correlation during surgery of pituitary adenomas. Methods : DTI tractography was used to tract the HHT in nine patients before craniotomy for pituitary adenomas. The DTI location of the HHT was compared with the PS position identified at the time of surgery. DTI fiber tracking was carried out in nine patients prior to the planned craniotomy for pituitary adenomas. In one patient, the PS could not be identified during the surgery. In the other eight patients, a comparison was made between the location of the HHT identified by DTI and the position of the PS visualized at the time of surgery. Results : The position of the HHT identified by DTI showed consistency with the intraoperative position of the PS in seven patients (88.9% concordance). Conclusion : This study shows that DTI can identify the position of the HHT and thus the position of the PS with a high degree of reliability.

• 한국지능시스템학회논문지
• /
• 제21권3호
• /
• pp.383-388
• /
• 2011

본 논문은 FIS(fuzzy inference system)와 신뢰도를 이용한 레이저 내비게이션의 정밀도 향상에 관한 것이다. 레이저 내비게이션은 무선 유도 장치로써 헤드가 $360^{\circ}$ 회전을 하며 벽에 부착된 반사체(reflector)를 읽어 AGV(automatic guided vehicle)의 위치를 측정하는 장치이다. 기존의 대표적인 유도 장치들의 타입은 유선 유도 방식이다. 이들은 정밀도가 매우 높고 반응속도가 빠르기 때문에 대부분의 현장에서는 이들을 채택하고 있다. 하지만, 이들 센서는 바닥 밑 1인치 안에 설치하거나 바닥에 심어야하기 때문에 설치비용은 매우 높고 유지 보수가 어렵다. 이러한 문제를 해결하기 위해서 레이저 내비게이션이 개발되었다. 이것은 바닥 시공 하는 것이 필요 없고 설치비용이 최소화되며 배치(layout) 변경이 쉽다. 하지만 외란에 영향을 많이 받아 데이터의 손실 손상이 크고 반응속도가 느리기 때문에 안전이 최우선인 산업현장에 사용이 어렵다. 이에 본 논문에서는 레이저 내비게이션의 정밀도 향상에 관한 연구를 하였다. 제안된 방법은 레이저 내비게이션의 특성을 분석하여 FIS를 통해 위치측정 정밀도의 신뢰도를 계산한 후에 이를 통해 레이저 내비게이션의 정밀도를 보정하는 방법이다. 본 논문에서는 실험을 위해서 직접 설계한 AGV를 이용하였으며, 레이저 내비게이션의 위치와 레이저 내비게이션의 신뢰도를 통해 보정된 위치를 제안된 방법과 비교 하였다. 실험 결과, FIS를 신뢰도로 보정한 결과가 다른 방법들에 비해 약 50% 성능이 향상됨을 확인하였다.

• 한국자동차공학회논문집
• /
• 제25권3호
• /
• pp.317-325
• /
• 2017

The EDR(Event Data Recorder) is a part of the ACU(Airbag Control Unit) functions mounted on a vehicle. EDR data have pre-crash data and post-crash data. Pre-crash data are recorded within 5 sec from time zero(AE) with 0.5 sec resolution, and reveal vehicle speed, engine rotation speed, throttle opening, brake pedal operation, acceleration pedal position and steering angle, etc. Using this EDR data, the investigation of a traffic accident can become more objective and scientific. Crash tests of three vehicles equipped with EDR function had been performed successfully. Evaluation of EDR data reliability had also been performed using Vbox and PC-Crash's sequence table function. Based on the results, we could confirm EDR data's reliability and availability for Traffic Accident Analysis by the series of this process.

• Journal of Audiology & Otology
• /
• 제24권2호
• /
• pp.107-111
• /
• 2020

The present study aimed to determine the test-retest reliability of subjective visual horizontal (SVH) testing when tested with solid and dotted line images. In this repeated measures study, 36 healthy young Malaysian adults (mean age=23.3±2.3 years, 17 males and 19 females) were enrolled. All of them were healthy and had no hearing, vestibular, balance, or vision problems. The SVH angles were recorded from each participant in an upright body position using a computerized device. They were asked to report their horizontality perception for solid and dotted line images (in the presence of a static black background). After 1 week, the SVH procedure was repeated. The test-retest reliability of SVH was found to be good for both solid line [intraclass correlation (ICC)=0.80] and dotted line (ICC=0.78). As revealed by Bland-Altman plots, for each visual image, the agreements of SVH between the two sessions were within the clinically accepted criteria (±2°). The SVH testing was found to be temporally reliable, which can be clinically beneficial. Both solid and dotted lines in the SVH testing are reliable to be used among young adults.