• Journal of the Semiconductor & Display Technology
• /
• v.7 no.3
• /
• pp.17-21
• /
• 2008

Application of flash memory in mobile and ubiquitous related devices is rapidly being increased due to its low price and high performance. In addition, some notebook computers currently come out into market with a SSD(Solid State Disk) instead of hard-drive based storage system. Regarding this trend, applications need to increase the storage capacity using multiple flash memory chips for larger capacity sooner or later. Flash memory based storage subsystem should resolve the performance bottleneck for writing in perspective of speed and lifetime according to its physical property. In order to make flash memory storage work with tangible performance, reclaiming of invalid regions needs to be controlled in a particular manner to decrease the number of erasures and to distribute the erasures uniformly over the whole memory space as much as possible. In this paper, we study the performance of flash memory recycling algorithms and demonstrate that the proposed algorithm shows acceptable performance for flash memory storage with multiple chips. The proposed cleaning method partitions the memory space into candidate memory regions, to be reclaimed as free, by utilizing threshold values. The proposed algorithm handles the storage system in multi-layered style. The impact of the proposed policies is evaluated through a number of experiments.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.10
• /
• pp.1809-1820
• /
• 2001

본 연구에서는 모 직물의 접착심과의 접착 후, 프레싱 처리 후, 드라이클리닝 처리 후 프레스로 처리한 실제의 의복의 관리와 생산 면에서 접할 수 있는 직물 변화에 대하여 물성 변화를 살펴보았다. 겉감으로는 신사복 춘하용 모 100% 또는 모혼방 직물 15종류를 사용하였으며 심지로는 신사복에 많이 쓰이는 3종류 심지를 사용하였다. KES시스템을 이용하여 직물의 접착후, 프레싱 처리 후, 드라이크리닝과 프레싱 처리 후의 물성 변화를 시험하였으며 다음과 같은 결과를 얻었다. 1) 접착 후 EM은 대체로 감소하지만 강성과 이력 현상은 증가하는 것으로 나타났다. 결과로 KOSHI, SHARI, HARI는 증가하고 THV는 감소하여 태는 접착으로 저하되었다. 2) 프레싱 처리 후는 접착 후와 큰 차이를 보이지 않는다. 마찰특성에서 좀더 매끄러워지고 마찰 계수는 증가하는 것으로 나타났다. 3) 드라이크리닝과 프레싱 처리 후의 물성의 변화에서는 위사 방향의 큰 값을 갖는 경우에 감소하는 것으로 나타났다. 굽힘 강성과 전단강성은 감소하였지만 이력은 증가하는 흥미로운 결과를 보인다. 드라이클리닝 용제의 효과로 여겨진다. 무게는 증가하여 직물이 처리 후 수축한 것으로 나타났다. 프레싱 처리 후와 비교시 KOSHI, SHARI, HARI와 FURAMl는 감소하고 THV는 증가하여 태가 향상하였다.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.1
• /
• pp.41-49
• /
• 2011

The diffuser which is conventionally adapted to MBR, has problem that decreasing the cleaning effect of membrane module by inflexible air supply due to the occlusion of sludge from diffuser hole. To solve this problem, diffuser structure of submerged module should be improved to discharge sludge which is flow into the diffuser for prevent occlusion in the diffuser. In this study, the structure of the diffuser was reformed to open lower part for preclusion the blocking. And the outlet diameter of the diffuser was drawn through the condition for the depth of water and air rate, to prevent air-leak condition of improved diffuser. Moreover, application is evaluated by comparing test with occlusion effect of the conventional and improved diffuser. From the results, air-water boundary changes are steady with changes of water depth and it shows linear relation about air rate. By using this linear numerical formula, the height of diffuser's outlet can be decided. Also, it displays that it can prevent the occlusion effect during the comparing test. Hereafter, if this diffuser is applied to practical MBR process, the occlusion problem of diffuser will be disappeared.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.4711-4717
• /
• 2011

Formation of TiN films by PVD method and the DC and RF sputtering deposition method can be applied, the injected gas to generate plasma ionization rate of the film forming speed is slow away, anything to increase the adhesion between films limitations have. To improve this, to investigate the deposition and ion beam evaporation simultaneously IBAD(Ion beam assisted deposition) when used, Ion beam surface coating material prior to the survey because the surface cleaning effect of a large, high film adhesion can be obtained. In addition, the high vacuum and low temperature, high purity thin film of uniform thickness in the benefits is.

• Journal of Korea Multimedia Society
• /
• v.14 no.5
• /
• pp.632-641
• /
• 2011

This paper presents a position error recognition system when the wafer is mounted in cleaning equipment among the wafer manufacturing processes. The proposed system is to enhance the performance in cost and reliability by preventing the wafer cleaning system from damaging by alerting it when it is put in correct position. The proposed algorithm is in obtaining a mapping function from camera and physical wafer by designing and manufacturing the radial shape calibrator to reduce the error by using the conventional chess board one. The system is to install in-line process using high reliable and high accurate position recognition. The experimental results show that the performance of the proposed system is better than that of the existing method for detecting errors within tolerance.

• Korean Journal of Materials Research
• /
• v.24 no.12
• /
• pp.682-688
• /
• 2014

Physical and chemical changes in a polished wafer and in $2.5{\mu}m$ & $4{\mu}m$ epitaxially grown Si layer wafers (Epilayer wafer) after surface treatment were investigated. We characterized the influence of surface treatment on wafer properties such as surface roughness and the chemical composition and bonds. After each surface treatment, the physical change of the wafer surface was evaluated by atomic force microscopy to confirm the surface morphology and roughness. In addition, chemical changes in the wafer surface were studied by X-ray photoemission spectroscopy measurement. Changes in the chemical composition were confirmed before and after the surface treatment. By combined analysis of the physical and chemical changes, we found that diluted hydrofluoric acid treatment is more effective than buffered oxide etching for $SiO_2$ removal in both polished and Epi-Layer wafers; however, the etch rate and the surface roughness in the given treatment are different among the polished $2.5{\mu}m$ and $4{\mu}m$ Epi-layer wafers in spite of the identical bulk structural properties of these wafers. This study therefore suggests that independent surface treatment optimization is required for each wafer type, $2.5{\mu}m$ and $4{\mu}m$, due to the meaningful differences in the initial surface chemical and physical properties.

• Textile Coloration and Finishing
• /
• v.23 no.4
• /
• pp.290-297
• /
• 2011

In this study, the possibility of the practical development of highly sensitive clothing textiles using fibrillated wool fibers were considered by determining the dyeability, the physical and mechanical properties of fibrillated wool fibers treated under strong acid and high temperature ultrasonic wave irradation and they were compared with those of untreated wool fibers. The color strengths of the dyed fibrillated wool fabrics increased by the acid metal complex dyes contrary to the untreated wool fabrics, and color fastness properties to rubbing, light, and dry cleaning were excellent, similar to those of the untreated wool fabrics. The tensile strengths of fibrillated wool fabrics were also kept after the dyeing. Moreover, the Numeri, Fukurami, and THV of the fibrillated wool fabrics were better than those of the untreated wool fabrics.

• Korean Journal of Community Nutrition
• /
• v.8 no.3
• /
• pp.270-279
• /
• 2003

Middle and high school students in Korea spend a lot of time at school. In other words, many Korean teenagers spend most of their time studying, and have little time for other activities, such as physical workouts. Fewer physical activities, and consumption of many snacks, etc. may lead to overweight or obesity in some teenagers. This study was conducted to find out the activity levels of teenagers' in order to calculate their daily energy expenditures. A total of 1,192 students (461 middle school students and 731 high school students) who lives in either a city or a country area were recruited for this study. One-day Activity Diaries were collected using questionnaires and analyzed by means of SPSS /win. The participating students spent about 7 hours 24 minutes resting including sleeping; 6 hours 28 minutes studying ,4 hours 4 minutes in leisure activities , 1 hour 32 minutes in personal hygiene activities such as washing, dressing and undressing, etc., 50 minutes on transportation : and 23 minutes on household chores such as cleaning, doing the laundry, etc. The average activity factor was 1.49. That of middle school female students was the lowest at 1.47, followed by middle school male students at 1.48, high school female students at 1.49, and high school male students at 1.51. The daily energy expenditure of middle and high school male students was 2,289 kcal and 2,600 kcal, respectively. That of female students was 1,959 kcal and 2,067 kcal, respectively.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.19 no.6
• /
• pp.955-967
• /
• 1995

This study was performed to investigate the physical and chemical properties of the 5 kinds of fabrics dyed with persimmon juice and undyed fabrics. The difference between dyed and undyed fabrics was checked experimentally. Obtained results are as follows. 1. Bending length and flex stiffness were increased after dyeing, and tensile strength of waif i3l fabrics except Ramie was also increased. 2. Abrasion resistance was improved in Ramie and Hemp after dyeing but the rest of fabrics were decreased. 3. Crease resistance of dyed fabrics was roughly worse than that of undyed fabrics. 4. Air permeability remarkably increased after dyeing and this fact estabilished that the traditional Gal-01 was cool clothing. 5. Water repellency in Cotton 1 and Polyester rises but the rest of fabrics were not changed. Therefore it is found that this repellency related to the their fabric counts. 6. Blocking effect of UV light and visible ray was increased in all dyed fabrics. Especially dyed Cotton 1 and Polyester blocked UV light almost perfectly. 7. The colorfastness to soaping and sunlight was proved to less than 3 grade in all fabrics after dyeing. It indicates that this colorfastness became worse owing to dyeing. 8. The colorfastness to dry cleaning and water was decided to more than 3 grade in all fabrics. 9. The colorfastness of the dyed fabrics to sweat after exposing to man-made acid sweat solution was good so that was decided above 3 grade. However after exposing to man-made alkalic sweat solution it became worse owing to dyeing.

• Applied Chemistry for Engineering
• /
• v.16 no.3
• /
• pp.440-448
• /
• 2005

Physical and chemical properties of waste glass, such as bottle glass, plate glass, and LCD glass were investigated to test the feasibility of starting materials for the production of high quality foamed glass for insulating grade construction material without pre-treatments such as cleaning, and waste removals. For this purpose, chemical analysis, thermal analysis, crystalline analysis, and rheological analysis including viscosity were proceeded and the preparation of foamed glass under the qualitative conditions obtained from these various analysis was also attempted. Overall results of various analysis and investigations for these waste glass showed that waste bottle glass and plate glass have high possivility of use as feed materials for the production of foamed glass.