• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.4
• /
• pp.368-380
• /
• 2005

File systems for flash memory that is widely used as a storage device for mobile devices should provide not only high-performance data reads and writes but also a guarantee on the data integrity even on a power failure. In this paper, we explain the design and implementation of a file system for flash memory that considers flash memory's physical characteristics and the data layout in the file system to give an optimized write performance. This file system guarantees the reliability against various system failures including a power failure by using the transaction concept in write processing. In addition, the file system minimizes the memory usage by using a simple static mapping. In the paper, we also describe the implementation of the file system and compare its performance with other existing flash memory ille systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.33 no.6
• /
• pp.465-470
• /
• 2020

Heterolayered K(Ta,Nb)O₃/Pb(Zr,Ti)O₃ thin films on Pt/Ti/SiO₂/Si substrates were prepared by a sol-gel process and spin-coating method. The structural and electrical properties were measured to investigate the possibility of application as an electrocaloric effect device. All specimens exhibited dense and uniform cross-sectional structures without pores, and the average thickness of the specimen coated six times was approximately 394 nm. Curie temperatures were observed at 5℃ or less in type-I and 10℃ in type-II specimens, respectively. Type-II specimens coated 6 times showed a relative dielectric constant of 758 and remanent polarization of 9.71 μC/㎠ at room temperature. The maximum electrocaloric effect occurred between 20 and 25℃, slightly higher than their Curie temperature, and the electrocaloric property (ΔT) of the type-II specimens coated 6 times was approximately 1.2℃ at room temperature.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.3
• /
• pp.95-101
• /
• 2009

Constructing large-scale mat foundation mass concrete is increasing for the stability of building structure, because a lot of high rise building are being built in order to make full use of limited space. However, It is of increasing concerns that because limited placing equipments, available job-site and systems for mass concete placement in construction field do not allow to place great quantity of concrete at the same time in large scale mat foundation, consistency between placement lift can not be secured. And also, it is likely to crack due to stress caused by the difference of hydration heat generation time. To find out the solution against above problems, this study is to reconfirm the performance of normal concrete designed by mix proportion and super retarding concrete. The Fundamental test shows what happens if low heat proportioning and control method of setting time are applied at the job-site of newly constructed high rise building. The test result show that slump flow of concrete has been somewhat increased as the target retarding time gets longer, while the air content has been slightly decreased but this is no great difference from normal concrete. The setting time shows to be retarded as target retarding time gets longer, the range of retarding time increases. It is necessary to increase the amount of mix of super retarding agent in the proportion ration by setting curing temperature high since outdoor curing is about 6 hours faster than standard curing, which means the temperature of the concrete will be higher than the temperature of the surrounding environment, due to its high hydration heat when applying in a construction site. The compressive strength of super retarding concrete appears to be lower than normal concrete due to the retarding action in the early stage. However, as the time goes by, the compressive strength gets higher, and by the 28th day the strength becomes the same or higher than normal concrete.

• International Journal of Highway Engineering
• /
• v.11 no.1
• /
• pp.69-83
• /
• 2009

According to the accident statistics of 2006, it can be recognized that drivers' characteristics and driving behaviors are the most causational factors on the traffic accidents. At present, many recording tools such as digital speedometer or black box are distributed in the market to meet social requests of decreasing traffic accidents and increasing safe driving behaviors. However, it is also true that the system preventing any possible vehicle accidents in advance has not been developed. In this study, we developed critical value for deciding dangerous driving behaviors. The developed critical value could be used to contribute to safety driving management systematization and safety driving behaviors.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.3
• /
• pp.105-115
• /
• 2005

This study was investigated the kinematic factors of the last approach strides and. take off motion for the skill improving of BKH elite male athlete. 'The subjects chosen for the study were BKH and. KASZCZYK Emillian male athletes who were participated in 2003 Dae-Gu Universiad Games. Three high speed video cameras set in 60frames/s setting were used. for recording from the last approach strides to the apex position. After digitizing motion, the Direct Linear Transformation(DLT) technique was employed to obtain 3-D position coordinates, The kinematic factors of the distance, velocity and angle variable were calculated for Kwon3D 3.1. The following conclusions were drawn; 1. It showed longer stride length, as well as faster horizontal and lateral velocity than the success trial during the approach phase. For consistent of the approach rhythm, it appeared that the subject should a short length for obtain the breaking force by the lower COG during the approach phase. 2. The body lean angle showed a small angle by a high COG during the take-off phase. For obtain the vertical displacement of the COG and a enough space form the bar after take-off, it appeared that the subject should increase the body lean angle. 3. For obtain the vertical force during the takeoff phase, it appeared that the subject should keep straight as possible the knee joint. Therefor, the subject can be obtain a enough breaking force at the approach landing.

• Archives of Plastic Surgery
• /
• v.32 no.5
• /
• pp.555-560
• /
• 2005

The nose is shaped as a pyramid and is the most prominent portion of the face. Nasal bone fractures are thus more frequent than those of the maxilla and zygoma. Whether the nasal bone fractures are corrected or not due to unnecessity of surgical treatment, the incidence of posttraumatic deformity occurs frequently. In Asian patients, even the corrected noses look low-lying and flat. To resolve these problems, we corrected the posttraumatic deformity of the nose with a combined procedure of nasal ostectomy and augmentation rhinoplasty. From 2000 to 2004, this procedure was performed in fifteen patients with posttraumatic nasal deformity. There were four female and eleven male patients with an average age of 32 years(range 19 to 52 years). All patients had previous trauma history. Of these, closed reduction was performed on 13 patients and no treatment was 2 patients. The deformed noses were corrected through lower columellar incision, by ostectomy or osteomy, and augmentation with silicone implant. We gained satisfactory results of correcting the deformed noses, except one case with implant deviation. Our method for the correction of traumatic nasal deformity proves to be simple and safe. The camouflage effect with silicone implant overcomes an unsatisfactory correction and brings a excellent cosmetic results.

• Archives of Plastic Surgery
• /
• v.34 no.4
• /
• pp.504-507
• /
• 2007

Purpose: Chondroid syringoma, previously known as 'mixed tumor of the skin', is a rare benign tumor. It usually presents an asymptomatic solitary firm intradermal or subcutaneous slowly growing nodule. It occurs frequently in the head and neck region of middle-aged men. We would like to report an uncommon chondroid syringoma about the clinical and histologic presentation. about the clinical and histologic presentation. Methods: We experienced two cases of chondroid syringoma on the nose and the upper lip, each other. Both masses were totally excised with clear margin. Results: On histologic examination, the masses showed a biphasic pattern-an epithelial component exhibiting apocrine/eccrine differentiation and a stromal component exhibiting myxoid/collagenous change-consistent with the diagnosis of chondroid syringoma. There have been no evidence of recurrence and malignant transformation during postoperative follow-up. Conclusion: There is no one distinctive clinical feature that is specific for chondroid syringoma. However, it should be included in the differential diagnosis of a solid nodule in head and neck region with long standing duration, such as epidermal inclusion cyst, pilomatrixoma, dermoid cyst, sebaceous cyst, neurofibroma, and basal cell carcinoma.

• Archives of Plastic Surgery
• /
• v.34 no.1
• /
• pp.111-114
• /
• 2007

Purpose: Dystrophic calcification occurs in damaged or devitalized tissues in the presence of a normal calcium and phosphorus metabolism. There are many reports on dystrophic calcification caused by injections of various types of drugs. The aim of this report is to highlight the fact that dystrophic calcification can be caused by the injection of a foreign body for aesthetic augmentation. Methods: This case report describes a patient presenting with dystrophic calcification caused by an injection of an unknown foreign body approximately 50 years ago. An 80-year-old man had localized cellulitis with swelling and ulceration on the dorsum of the left hand. The radiographs demonstrated a $5{\times}3.5{\times}1.7cm$ lesion between the first and second metacarpal bones and a $5{\times}2.5{\times}1.5cm$ lesion in the hypothenar region. The laboratory data and physical examinations were generally within the normal limits. The microscopic examination revealed dead bone fragments and dense collagenous tissue with dystrophic calcification. Results: After surgically removing the masses, the resulting defects were treated with an abdominal flap. The result was satisfactory in terms of symptoms and appearance. Conclusion: This case suggests that dystrophic calcification can be caused by an injection of a foreign body for aesthetic augmentation.

• Archives of Plastic Surgery
• /
• v.34 no.1
• /
• pp.70-76
• /
• 2007

Purpose: Full-thickness skin grafts are usually used in facial reconstruction, but on occasion, split-thickness skin graft is also used from the scalp due to the limitation of donor site. However, there were complications, such as alopecia, folliculitis and blood loss. In addition, it can not be used in patients with baldness. Under the circumstances, we used medial arm skin as split-thickness skin graft donor site in lieu of scalp. We investigated the efficacy of the medial arm skin as a donor site of facial skin graft in comparison with scalp. Methods: From 2000 to 2005, the split-thicknesss skin grafts were performed using the medial arm skin in 10 patients and the scalp in 10 patients. We inspected the skin color match, texture match by the visual analogue scale. Scar contracture was estimated by the Visitrak $grade^{(R)}$(Smith & Nephew). The statistical analysis was performed by SPSS 12.0. Results: There was a more satisfaction in color match, texture, and scar contracture in medial arm skin than in scalp. Conclusion: According to these results, medial arm skin may be used efficiently as an alternative donor site of scalp in the facial reconstruction.

• The Journal of Korean Physical Therapy
• /
• v.19 no.6
• /
• pp.23-30
• /
• 2007

Purpose: This study examined the correlation between the maximum voluntary isometric contraction (MVIC) and the muscle architecture in the extensor carpi radialis longus muscle during MVIC. Methods: The muscle area, volume were measured using a ultrasound imaging system to obtain the muscle architecture during the MVIC. For the mechanical muscle strength measurements, the MVIC was obtained using a dynamometer. Results: There was a significant correlation between the MVIC and the muscle area (r=0.498, p<0.01) and muscle volume (r=0.602, p<0.001). There was a significant correlation between the MVIC and density (r=-0.429, p<0.05). The area showed significant correlations with the muscle volume (r=0.699, p<0.001) and density (r=-0.429, p<0.05). In addition, there was a correlation between the volume and muscle density (r=0.555, p<0.01). Conclusion: There is close relationship between the MVIC and the muscle architecture in the extensor carpi radialis longus muscle during the MVIC.