• Proceedings of the Korea Information Processing Society Conference
• /
• 한국정보처리학회 2010년도 춘계학술발표대회
• /
• pp.369-372
• /
• 2010

평판 디스플레이(flat panel display)의 크기가 커짐에 따라 다양한 기판을 이용한 제조 방법이 개발되고 있다. 디스플레이 제조 공정 중 기판의 결함을 찾아서 분류하는 검사 시스템은 최종 제품의 품질을 결정하는 매우 중요한 부분이다. 본 연구는 머신비전 기술을 이용하여 불투명하고 반사율이 높은 기판 표면의 결함을 찾아내고, 이 결함을 스크래치(scratch), 흑결함(dark defect), 백결함(white defect)으로 분류하는 장치를 구현하는데 목적이 있다. 이를 구현하기 위해 본 논문에서는 정밀 스테이지(stage)와 라인 카메라(line CCD camera)을 이용한 광학계를 활용하여 검사 시스템을 구현하였다. 구축된 시스템을 이용하여 취득한 이미지를 12 개의 영역으로 등분하여 각각의 국부 영역에 대한 문턱값 연산(thresholding)을 적용함으로써 조명의 불균일을 의한 검출 에러율을 획기적으로 낮추었다. 간단한 컴퓨터비전 알고리듬의 채용으로도 검사 시스템의 구현이 가능함을 보였다.

• Journal of radiological science and technology
• /
• 제45권6호
• /
• pp.483-489
• /
• 2022

This study proposes a new skull lateral examination, and provides an improved examination environment for patients and radiologists. The study was divided into three groups. One group was divided into the SID (source to image receptor distance) 110 ㎝ and 180 ㎝ in the skull lateral posture, the other group The other group was divided into an position in contact with the detector and an position without contact with the detector, and the other group was divided into male and female groups, considering that the difference in shoulder width between adult males and females would affect the dose and image quality. For dose evaluation, the ESD (entrance surface dose) was measured at the EAM (external auditory meatus), and the conditions were applied equally at 70 ㎸p, 200 ㎃, and 10 ㎃s. For image quality evaluation, SNR (signal to noise ratio) and CNR (contrast to noise ratio) were measured in frontal sinus, EAM, and sella turcica. As a result of ESD comparison, when sid 110 ㎝ to sid 180 ㎝ was changed among the three groups, ESD values decreased the most to 729.18±4.62 μ㏉ and 224.18±0.74 μ㏉ at 180 ㎝ (p<0.01). The values of SNR and CNR were statistically significant (p<0.01), but there was no qualitative difference. This shows that when the SID is 180 ㎝, it is possible to reduce the dose without lowering the image quality. So, It is suggested that the SID 180 ㎝ is used without contacting the detector when examining the skull lateral.

• Journal of Navigation and Port Research
• /
• 제28권1호
• /
• pp.43-49
• /
• 2004

Defects inspection of commodities are very important with those design and manufacturing process and essential to strengthen the competitiveness of those. If on-line automatic defects detection is performed without damaging to products, the production cost shall be curtailed through the reducing man-power, economical management of Q.C(Quality Control). In this paper, it is suggested three spatial filtering methods which can extract the necessary information in case of defects being on the surface of object like iron plate. In addition, the dependence of filtering characteristics on parameters such as the pitch and width of slits is analyzed and the surface defect detection system is constructed. Several experiments were carried out for determining the adequate spatial filtering method through comparing and analyzing effects of parameters like defect's size and shape, intensity of light, noise of coherent source and slit number.

• Korean Journal of Food Science and Technology
• /
• 제26권3호
• /
• pp.250-254
• /
• 1994

The quality characteristics of freeze-dried Chungkook-jang soup, stored at $25^{\circ}C$, $35^{\circ}C$ and $45^{\circ}C$ was investigated. Peroxide value(POV) was increased as the storage time was extended. Browning reaction occured earlier in the sample stored at $45^{\circ}C$ than those stored at $35^{\circ}C$ and $25^{\circ}C$. Red color developed more intensely in the sample stored at $45^{\circ}C$. However, moisture content was not changed during storage. Regression analyses between sensory scores and quality characteristics showed that the peroxide formation of oil contained in Chungkook-jang soup was the major quality index for the deterioration of Chungkoak-jang soup.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
• /
• pp.188.2-189
• /
• 2003

시설재배 만감류인 부지화 감귤의 수확후 저장유통시 부패 감소 및 상품성 제고를 위하여 환경친화적 전처리방법으로서 중온처리의 적용 가능성을 확인하고자, 제주 서귀포산 부지화(한라봉)감귤의 열수 및 열풍 처리에 따른 저장중 품질특성 변화를 살펴보았다. 표면상처가 없는 일정 크기의 건전 과실을 선별한 후, 각각 52$^{\circ}C$에서 2분(52-2m), 6$0^{\circ}C$에서 20초(60-20s) 동안 열수에 침지하거나 45$^{\circ}C$에서 4시간(45-4h), 8시간(45-8h) 동안 열풍을 가한 다음 5$^{\circ}C$에서 냉각 건조하였다. 충분히 냉각된 과실을 통기성 천공 LDPE 필름에 포장하여 5"C에서 21일, 18$^{\circ}C$에서 7일간 저장하면서 생리, 이화학, 관능적 특성을 측정하였다. 중온처리 직후 초기 호흡률은 처리구 모두 무처리구와 비교하여 다소 높았으나, 저장중 처리구 감귤의 호흡률은 감소하여 21일째는 무처리구와 동일한 수준을 나타내었다. 과실내 기체조성은 저장기간 및 처리구간에 차이를 보이지 않았으나 21일부터는 저장온도 전환에 따라 $CO_2$가 다소 증가하는 양상을 보였다. 과실의 pH, 산도, 경도는 중온처리에 따른 유의적 차이를 구분할 수 없었으나, 고형분 함량과 생체 중량감소율은 열풍처리구에서 다소 높게 유지되었다. 과피 표면색 역시 열풍처리구 (45-8h)가 다른 것에 비해 저장중 짙게 나타났으나 열수처리구에서는 가시적 변화를 발견할 수 없었다. 한편 부패과 발생률에 있어서 열수처리구가 축부병 등에 의한 짓무름 현상 및 곰팡이 발생정도를 가장 낮게 나타내었고, 관능검사에서도 열수처리구가 변색, 시듦, 광택 등의 외관 품질항목에서 유의적으로 우수하게 평가되었다. 결과적으로 중온 열수처리는 부지화 김귤의 수확후 저장유통중 부패과 발생률을 감소시키고 외관품질을 유지하는데 효과적인 전처리방법임을 확인할 수 있었다. 있었다.

• Journal of the Korean Society of Radiology
• /
• 제17권4호
• /
• pp.573-579
• /
• 2023

This study compares dose difference between the presence or absence of grid in Chest PA radiography using auto exposure control and compares image quality among presence, absence or virtual grid, and proposes a new clinically useful grid combination for chest radiography. The human body phantom was placed Chest PA position and the dosimeter was placed at T6. The same irradiation conditions and field size were applied. 30 images were obtained in the state in which grid was applied and in the state in which grid was not applied, and an additional 30 images in which the virtual grid was applied to the image without the grid were obtained. Radiation dose was presented to entrance surface dose. The image quality was analyzed by comparing the signal-to-noise and contrast-to-noise ratio. ESD decreased by 48% when the grid was not used, compared to when the grid was used. SNR and CNR increased by 32% and 30% compared to grid use when grid was not used, respectively. In the case of using the virtual grid, it increased by 18% and 16% respectively, compared to the case of using the grid. As a result of this study, it is believed that when using a virtual grid instead of a grid, the quality of the image can be maintained while reducing the patient dose.

• Journal of the Korea institute for structural maintenance and inspection
• /
• 제26권1호
• /
• pp.89-96
• /
• 2022

In this paper, to evaluate the output quality of the cementitious composite mixture for printing with the ME method for construction 3D printer, visual inspection of the output appearance and the dimensional error rate, compressive strength and flexural strength of the output were measured. As a result of the test, the mixing design with excellent output appearance was P1-2, P1-4, P2-5, P2-6, and the mixing design with good output appearance was P0-1, P1-1, P1-3, P1-6, P1-7 and P2-4. Of these mixing designs, P0-1 and P2-6 had the lowest dimensional error rates As a result of evaluating the compressive strength and flexural strength of the various mixing designs, the Mixing design with excellent output designs showed good mechnical properties. However, mixing designs with excellent mechanical properties does not necessarily have excellent output quality. Therefore, in order to accurately evaluate the output quality, it is judged that visual inspection and dimensional error rate inspection should be performed first, and then the mechanical characteristics should be reviewed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 한국해양정보통신학회 2001년도 춘계종합학술대회
• /
• pp.399-403
• /
• 2001

One of the most important factors for a leather quality inspection is its surface condition. So far, a leather quality level has been discriminated by human's eye inspection. But, these kinds of method needs a lot of labor time and cause decision mistakes from an optical illusion. It means leather quality inspection is very subjective and there is no consistency. In this study, we present computer vision based a leather quality inspection system using an Artificial intelligence. Suggested system can give standard spec for a leather quality and take human inspection duty place.

• Journal of the Korean Society for Nondestructive Testing
• /
• 제33권4호
• /
• pp.368-375
• /
• 2013

Failure of small bore piping welds is a recurring problem at nuclear power plants. And the socket weld cracking in small bore piping has caused unplanned plant shutdowns for repair and high economic impact on the plants. Consequently, early crack detection, including the detection of manufacturing defects, is of the utmost importance. Until now, the surface inspection methods has been applied according to ASME Section XI requirements. But the ultrasonic inspection as a volumetric method is also applying to enforce the inspection requirement. However, the conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. And there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD(outer diameter) surface of small bore piping. In this study, phased array ultrasonic inspection technique is applied to increase inspection speed and reliability. To achieve this object, the 3.5 MHz phased array ultrasonic transducer are designed and fabricated. The manually encoded scanner was also developed to enhance contact conditions and maintain constant signal quality. Additionally inspection system is configured and inspection procedure is developed.

• Korean journal of food and cookery science
• /
• 제20권2호
• /
• pp.180-186
• /
• 2004

Evidence shows there are flavonoid and polyphenol compounds in Ulmus cortex which has excellent antioxidant, anticancer and antimicrobial properties. This study summarizes our findings on effects of Ulmus cortex extracts(UDE) on quality characteristics of bread and the changes of microbial counts during storage. Dough yield and specific loaf volume of bread decreased significantly because the amount of UDE increased. Lightness of bread surface, redness of crumb and yellowness of crust were significantly increased. Texture evaluation showed that hardness was the highest in the bread prepared with 30% UDE. Sensory evaluation showed that odor, taste, texture, and overall acceptability were the best in bread which was made with 10% UDE. At the beginning of the period of storage, there were not significant differences of microbial cell count as increasing UDE, but significant decreasing was observed after passing 6 days. A negative correlation was generally observed between the sensory and mechanical properties. The results of total microbial count show that adding UDE in processing bread extend bread's storage time.