• 한국융합학회논문지
• /
• 제10권4호
• /
• pp.39-43
• /
• 2019

표면실장장비(SMD)의 겐트리는 부품을 피더에서 기판으로 옮기는 역할을 한다. 이 때 겐트리의 이동 시간은 생산량에 영향을 미친다. 따라서 본 논문에서는 겐트리의 이동 시간을 단축시키기 위해 부품의 흡착에서 실장까지 가장 빠른 경로를 제시한다. 이 경로는 겐트리의 특성상 카메라 앞에서의 속도가 2인 경우이다. 따라서 이때의 궤적 그래프를 시뮬레이션을 통해 작성하고 이동 시간을 계산하였다. 그 결과 현재 사용 중인 stop-motion방법보다 본 논문에서 제시한 moving-motion방법의 이동 시간이 20%단축된 것을 알 수 있다.

• Design & Manufacturing
• /
• 제16권1호
• /
• pp.21-26
• /
• 2022

In the CNC machining process, problems such as lowering of machine operation rate, setting errors, and machining precision occur due to the increase in setting time and preparation time. These machining errors cause delays in delivery and increase in cost due to an increase in the number of mounting and dismounting of the workpiece, an increase in measurement and reprocessing time, and an increase in the finishing time in the assembly process. Therefore, in this study, by automating the setting of the work piece using OMV (On Machine Verification), which is a meteorological measurement system, the preparation time for machining the work piece and the setting accuracy were improved, the rework rate was reduced, and the mold manufacturing process was shortened. Through the advancement, standardzation, and automation of the mold part manufacturing process, we have improved productivity by minimizing low-value-added repetitive tasks. In addition, the measurement time was reduced by more than 50% and the machining measurement rate was improved by more than 20%, eliminating repetitive work for correcting machining defects, and reducing the work preparation time by more than 15% through automatic setting.

• 대한임베디드공학회논문지
• /
• 제2권3호
• /
• pp.184-193
• /
• 2007

Flash memory adoption in the mobile devices is increasing or vanous multimedia services such as audio, videos, and games. Although the traditional research issues such as out-place update, garbage collection, and wear-leveling are important, the performance, memory usage, and fast mount issues of flash memory file system are becoming much more important than ever because flash memory capacity is rapidly increasing. In this paper, we address the problems of the existing log-based flash memory file systems analytically and propose an efficient log-based file system, which produces higher performance, less memory usage and mount time than the existing log-based file systems. Our ideas are applied to a well-known log-based flash memory file system (YAFFS2) and the performance tests are conducted by comparing our prototype with YAFFS2. The experimental results show that our prototype achieves higher performance, less system memory usage, and faster mounting than YAFFS2, which is better than JFFS2.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
• /
• pp.394-401
• /
• 2003

We consider a PCB grouping problem arising from the electronic industry. Given a surface mounting device, several types of PCBs and a number of component feeders used to assemble the PCBs. the optimization problem is the PCB grouping problem while minimizing setup time of component feeders. We formulate the problem as an Integer programming model and propose a column generation approach to solve the Integer programming formulation. In this approach we decompose the original problem Into master problem and column generation subproblem Starting with a few columns in the master problem. we generate new columns successively by solving subproblem optimally. To solve the subproblem. we use a branrh-and-rut approach. Computational experiments show that our solution approach gives high quality solutions in a reasonable computing time.

• 조명전기설비학회논문지
• /
• 제23권7호
• /
• pp.75-80
• /
• 2009

In this study, a Web server was constructed using LabVIEW's DataSocket, which makes possible acquisition, analysis, and saving in real time. The output value of the optical current sensor at the web server PC was measured and the output value was displayed using the Web browser of the client PC. DataSocket by LabVIEW makes the construction of a Web server easier than other languages and is compatible with other application programs. An optical current sensor was composed using a 1310 [nm] laser diode, and 9/125 [${\mu}m$] standard single mode optical fiber and was created to be a close type sensor. Data measurement using Web servers has the advantage of monitoring electric power systems at a great distance and can fuse IT technology and electric power systems. Also, this measurement uses inexpensive mounting and programming when compared to existing measurement equipment allowing the construction of a measurement system in any situation or surrounding.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2022년도 추계학술대회
• /
• pp.411-413
• /
• 2022

본 논문에서는 FoV(Fiele Of View)에 따른 감지거리 변화와 반사체에 따른 감지거리 고려하여 TOF(Time Of Flight) 센서의 장착 위치를 측면부 설치 시와 전/후면부 설치 시로 나누어 맞춘 개발을 수행하도록 한다.

• 한국정보과학회논문지:시스템및이론
• /
• 제35권11호
• /
• pp.497-508
• /
• 2008

본 연구는 NAND 플래시 메모리를 기반으로 하는 모바일 멀티미디어 파일시스템(MNFS)에 관한 내용이다. 이 연구에서 제안하는 파일시스템은 기존 범용 플래시 파일시템과는 달리 MP3 플레이어, PMP, 디지털 캠코더 둥과 같은 모바일 멀티미디어 장치에서 최적의 성능을 보장하기 위하여 설계된 파일시스템이다. MNFS는 크게 세 가지의 특징을 갖는데, 첫째 파일시스템의 순차적인 쓰기 요청에 대해 균일한 응답시간을 보장하고, 둘째 파일시스템 마운트 시간이 빠르며, 셋째 최소한의 메모리만을 소모한다. 이를 위해 4가지 새로운 기법들을 사용한다. 파일시스템 메타데이타와 사용자 데이타를 서로 다른 맵핑 기법으로 관리하는 혼합 맵핑 기법과, 파일 데이타 할당 단위를 NAND 플래시 메모리의 블록 단위로 사용한 블록 단위사용자 데이타 할당, 메타데이타를 최소화하기 위한 iBAT, 그리고 상향식 디렉토리 표현기법이다. 프로토타입 MNFS를 ARM9 프로세서와 1G 비트 용량의 NAND 플래시 메모리환경에서 구현하고 성능을 측정한다. 기존의 NAND 플래시 파일시템인 YAFFS와 FTL을 사용하는 FAT 파일시스템과 비교하였으며, 순차적 쓰기 요청에 대해 빠르고 균일한 응답시간을 확인할 수 있다. 또, 같은 조건에서 YAFFS에 비해 30배 빠른 마운트 시간을 보였고, Heap 메모리도 YAFFS의 5%밖에 소모하지 않았다.

• 한국수정란이식학회지
• /
• 제22권3호
• /
• pp.185-190
• /
• 2007

본 연구는 젖소 경산우와 미경산우의 다양한 발정 행동 특성과 배란 시간을 조사하기 위해 수행되었다. 공시된 89두 중 73두에서 배란이 일어났으며, 이 중 61두에서 발정 발현이 나타났다. 다양한 발정 행동은 $PGF_2{\alpha}$ 투여 후 2일째부터 72시간 동안 육안 관찰하였으며, 배란 시간(4시간 간격으로 초음파 시험)과의 관계를 각각 조사하였다. 경산우의 발정 발현율은 외음부 냄새 맡기, 턱 비빔, 승가 및 승가 허용에서 각각 81%, 78%, 78% 및 56%로 나타났으며, 미경산우에서는 외음부 냄새 맡기, 턱 비빔, 승가 및 승가 허용은 각각 61%, 68%, 82% 및 76%를 보였다. 젖소 경산우와 미경산우에서 발정 개시 후 배란까지의 평균 $25.58{\pm}7.94$와 $25.55{\pm}5.72$시간이었으며, 발정 종료 후 배란까지는 평균 $13.42{\pm}7.14$와 $7.48{\pm}7.4$시간이었다. 경산우의 발정 개시 후 배란까지의 시간에서는 승가 허용($17.33{\pm}5.83$시간)이 승가, 외음부 냄새 맡기, 턱 비빔($23.58{\pm}5.12$시간, $24.25{\pm}6.09$시간, $23.42{\pm}6.04$시간)보다 유의적으로(p<0.05) 짧게 나타났으며, 미경산우에서는 유의적인 차이가 인정되지 않았다. 승가 허용 종료에서 배란까지의 시간에서는 미경산우($6.38{\pm}4.80$)가 경산우($13.05{\pm}4.53$)에 비해 유의적으로(p<0.05) 짧게 나타났다. 본 연구 결과에 의해 우유생산에 관련한 생리적인 변화가 젖소 발정행동과 배란 특성의 변화의 주요 요인일 수 있다고 사료된다.

• 한국가축번식학회지
• /
• 제9권2호
• /
• pp.140-147
• /
• 1985

Seventy four Holstein heifers were randomly assigned over three trials to PRID-7+PG-6 and Synchromate B-9 regimens to synchronize estrus cycle for embryo transfer. Sexual behaviors; moounting, standing, orientation, chin-resting, sniffing, licking, rubbing and butting, vaginal swelling and mucus discharge were observed between 06-08, 12-14 and 18-20 h on 1st day and 00-02, 06-08, 12-14 and 18-20 h on 2nd day after removal of hormones. Synchromate-B treatment (81.6%) showed higher synchronized estrus rate than PRID treatment (77.8%) during observation period. Standing estrus was observed within 74 h after PG injection in PRID and within 52 h after removal of implant in Synchromate-B. About 68% of heifers in PRID and 74% of heifers in Synchromate-B showed standing estrus between 0-14 h on 2nd day after removal of the hormones. Synchromate-B resulted in a tighter synchrony of standing estrus than PRID. Incidence of average mounting and standing per head during observation period was 22.3 and 16.6 in PRID and 28.1 and 13.6 in Synchromate-B. The PRID showed peak in active mounting at 18-20 h on 1st day, however, the Synchromate-B showed at 0-2 h on 2nd day after removal of hormone. Active standing was shown between 18 h on 1st day to 20h on 2nd day in PRID, however, between 0-14 h on 2nd day after removal of hormone is Synchromate-B. There was slight difference in pattern of active mounting and standing during estrus between PRID and Synchromate-B. Conception rate of synchronized heifers transferred with fresh and frozen embryos by non-surgical and surgical methods was higher in synchromate-B (62.5%) than in PRID (38.5%). Chin-resting showed highest incidence among 6 sexual behavioral components in the both treatments. Synchromate-B showed higher incidence of chin-resting (16.6) than PRID (10.7). Synchromate-B group showed also higher incidence of orientation, sniffing and butting than PRID group. Synchromate-B resulted in more active sexual behaviors than PRID. The pattern of incidence of chin-resting, licking and butting was almost symmetrical in PRID with their peak values at 6-8 h on 2nd day, however in Synchromate-B chin-resting and sniffing was symmetrical with their peak values at 12-14 h on 2nd day after removal of hormone. There was tendency to increase vaginal swelling according to time passage of synchronized estrus in the both treatments. Incidence of mucus discharge in Synchromate-B was slightly higher than in PRID. Twenty to 40% was false negative in conception rate by tall painting before re-estrus day as judged by rectal palpation.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제12권2호
• /
• pp.51-56
• /
• 2006

Use of products containing phytoecdysteroid (PE) as active principle has become popular in prominent sericultural areas of India for hastening larval maturation events and synchronizing cocoon spinning activities as an obvious advantage is assured. At times, the present recommendation of administering PE at the onset of spinning results in peak labour requirement at odd hrs. To enable making recommendation for the use of PE on $multi{\times}bivoltine$ silkworm hybrids based on the climatic conditions prevailing in different areas especially with regard to temperature, the experiment was taken up to determine proper treatment times so that the induced spinning will be more orderly and the labour can be leveraged more efficiently. Different brackets of low ($18-22^{\circ}C$), medium ($24-28^{\circ}C$) and high ($29-32^{\circ}C$) temperature were simulated during the latter half of V larval instar and cocoon spinning. PE was administered to $multi{\times}bivoltine$ silkworm ($BL67{\times}CSR101$) hybrid batches as per the recommended dose at three different times viz., 10 am, 4 pm and 10 pm. Three replicates of 100 larvae were maintained for each treatment. Absolute controls were also maintained in each temperature range to compare the results. Cumulative maturation percentage was recorded at 6 hrs interval to ascertain peak mounting span. The influence of the treatment on the cocoon traits also was studied. Based on the peak mounting span, it was evident that in low temperature 10 pm treatment would be better. In medium and high temperature, treatment at 4 pm proved to be a better option. The influence of the treatment times at different temperature range on labour management is discussed.