• Journal of KIISE:Computer Systems and Theory
• /
• v.35 no.11
• /
• pp.497-508
• /
• 2008

Mobile Multimedia File System, MNFS, is a file system which extensively exploits NAND FLASH Memory, Since general Flash file systems does not precisely meet the criteria of mobile devices such as MP3 Player, PMP, Digital Camcorder, MNFS is designed to guarantee the optimal performance of FLASH Memory file system. Among many features MNFS provides, there are three distinguishable characteristics. MNFS guarantees, first, constant response time in sequential write requests of the file system, second, fast file system mounting time, and lastly least memory footprint. MNFS implements four schemes to provide such features, Hybrid mapping scheme to map file system metadata and user data, manipulation of user data allocation to fit allocation unit of file data into allocation unit of NAND FLASH Memory, iBAT (in core only Block Allocation Table) to minimize the metadata, and bottom-up representation of directory. Prototype implementation of MNFS was tested and measured its performance on ARM9 processor and 1Gbit NAND FLASH Memory environment. Its performance was compared with YAFFS, NAND FLASH File system, and FAT file system which use FTL. This enables to observe constant request time for sequential write request. It shows 30 times faster mounting time to YAFFS, and reduces 95% of HEAP memory consumption compared to YAFFS.

• Journal of Internet Computing and Services
• /
• v.6 no.6
• /
• pp.139-148
• /
• 2005

The desired level for multimedia services in the mobile web environment, the next generation web environment, is expected to be of PC level quality. And great efforts have been made in the development of hadware technology, communication technology, various kinds of services and standardization to support these services, In the mobile web environment, multimedia contents adaptation services should be available through supporting various kinds of devices, network abilities and users' preferences. It means that due to the variety of both desired devices' hardware specifications, called destinations, and desired QoSes, the QoSes in the destinations are not fixed or defined. If a new user wants to stream multimedia contents in a server through a new kind of terminal device, it should be considered whether the existing transcoders are able to adapt the multimedia contents. However, the existing libraries for multimedia adaptation have heavy transcoder figures which include all adaptive functions in one library, The challenge of universal access is too complex to be solved with these all in one solutions. Therefore, in this paper we propose an application independent multimedia adaptation framework which meets the QoS of new and varied mobile devices. This framework is composed of a group of unit transcoders having only one transcoding function respectively, Instead of heavy transcoders. Also, It includes the transcoder manager supporting the dynamic connections of the unit transcoders in order to satisfy end to end QoS.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2009.11a
• /
• pp.79-82
• /
• 2009

본 연구는 인터넷의 진화 및 이미징 디바이스 전반의 발달에 따른 디지털 카메라의 진화 전략을 다룬 논문이다. 오늘날의 카메라 기술은 하루가 다르게 발전해 나가고 있다. 수동 필름 카메라에서부터 최첨단 하이브리드(hybrid) 카메라에 이르기 까지 카메라는 끊임없이 진화해 왔으며 사용자 계층 역시 다양해지고 있다. 디지털이 적용된 디지털 카메라의 경우, 웹의 발전과 더불어 활용도가 다양해 짐에 따라서 기존에는 전문가와 비전문가 계층으로 명확하게 나뉘던 사용자 계층도 그 경계가 모호해졌으며 사용자의 수 역시 비약적으로 증가하였다. 수많은 사업자들이 디지털 카메라 시장에 진출함에 따라, 높은 성장세가 지속되던 컴팩트 카메라 (compact camera)시장은 과포화기에 접어들어 성장성이 점차 감소하는 추세에 있으며, 전문가의 영역으로 여겨졌던 DSLR 시장 역시 선발업체의 높은 진입장벽과 이를 극복하기 위한 후발업체의 지속적인 도전으로 인해 경쟁은 치열하고 이익은 내기 어려운 레드 오션(red ocean)이 되었다. 이러한 상황 속에서 디지털 카메라가 활용될 수 있는 대표적 매체인 웹 역시 '웹 2.0' 이라는 용어가 생길 정도로 발전했다. 웹2.0시대가 본격화되어 서로 다른 사용자들이 자유롭게 컨텐츠를 공유하고 누구든지 쉽게 정보의 생산에 동참할 수 있게 됨으로써 기존의 웹에서 일어나지 않았던 다양한 변화들이 생겨나게 되었다. 본 연구에서는 변화의 특징들을 살펴보기 위해 웹 2.0 시대의 대표적인 컨텐츠 공유 커뮤니티로 자리매김한 야후(Yahoo)사(社) 플리커(Flickr)의 사례를 통해 디지털 카메라 사용자들의 디지털 카메라 사용패턴을 살펴보고 이를 통해 디지털 카메라의 진화를 설명하고자 한다. 인터넷이 발전하며 디지털 카메라와 관련 되어 나타난 대표적인 변화는 일반 소비자가 진화하는 점 이라고 볼 수 있다. 컨텐츠의 공유가 자유로운 웹 플랫폼의 등장, 카메라 기술이 결합된 소형 디지털 단말기의 발전 등으로 인해 비전문가 영역에 속해있던 일반 소비자 계층에 Flickr와 같은 웹 커뮤니티에서의 활동을 통해 준전문가 계층으로 진입하려는 욕구가 생기게 되었는데, 이렇게 형성된 욕구에 따라 디지털 카메라 시장 역시 새로운 수요를 만나게 되었다. 본 연구에서는 경쟁이 치열한 시장 상황 속에서 디지털 카메라의 향후 발전 방향을 알아보기 위해 우선 디지털 카메라 기능을 나누어 본 후, 이미징 디바이스 시장과 웹의 발전 형태에 대해 분석해보았다. 이어 본 연구에서는 분류된 디지털 카메라의 기능을 바탕으로 웹 2.0 시대에 시장을 주도할 수 있는 디지털 카메라의 변화방향에 대해서 알아보았다. 본 연구는 감성적 및 이성적 측면에서 디지털 카메라의 향후 전개방향을 살펴보았다는 점에서 이론적 실무적 함의를 가지는 논문이라고 사료된다.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.7
• /
• pp.433-441
• /
• 2007

The bio-Sensors, which are sensing the vital signs of human bodies, are largely used by the medical equipment. Recently, the sensor network technology, which composes of the sensor interface for small-seize hardware, processor, the wireless communication module and battery in small sized hardware, has been extended to the area of bio-senor network systems due to the advances of the MEMS technology. In this paper we have suggested a design and implementation of a health care information system(called u-EMS) using a bio-sensor network technology that is a combination of the bio-sensor and the sensor network technology. In proposed system, we have used the following vital body sensors such as EKG sensor, the blood pressure sensor, the heart rate sensor, the pulse oximeter sensor and the glucose sensor. We have collected various vital sign data through the sensor network module and processed the data to implement a health care measurement system. Such measured data can be displayed by the wireless terminal(PDA, Cell phone) and the digital-frame display device. Finally, we have conducted a series of tests which considered both patient's vital sign and context-awared information in order to improve the effectiveness of the u-EMS.

• The korean journal of orthodontics
• /
• v.40 no.6
• /
• pp.364-372
• /
• 2010

Objective: This study was designed to assess the diagnostic validity of digital panoramic radiographs compared to cone beam computed tomography (CBCT) in patients with temporomandibular joint disorders. Methods: Panoramic radiograph and CBCT were taken from a total of 212 joints from 106 subjects. The joints were examined by two dentists and divided into the following six groups: normal, flattening, osteophyte formation, erosion, sclerosis, and unclassified. The sensitivity and specificity of each observer and inter-observer reliability were statistically analyzed. Results: The results showed relatively high intra-observer reliability in the diagnosis of both panoramic and CBCT images and the weighted Kappa indices of panoramic and CBCT images were 0.714 and 0.727, respectively. The sensitivities of panoramic images of observer A and B to CBCT images was 82.35% and 84.30%, respectively, while the specificity of observer A and B was 58.06% and 61.54%, respectively. However, guided diagnosis from panoramic and CBCT images were statistically different (p < 0.05). Conclusions: The present study suggests that the panoramic radiograph could be used as a primary diagnostic device to detect bony changes of temporomandibular joints in clinical orthodontics, because panoramic images showed relatively high sensitivity compared to CBCT images. However, CBCT images may be one of the best choices when a more accurate diagnosis is necessary.

• Journal of IKEEE
• /
• v.13 no.4
• /
• pp.116-124
• /
• 2009

Recently the CPU performance of modem chipsets or multimedia processors of mobile phone is as high as notebook PC. That is why mobile phone has been emerged as a leading ICON on the convergence of consumer electronics. The various applications of mobile phone such as DMB, digital camera, video telephony and internet full browsing are servicing to consumers. To meet all the demands the image quality has been increasingly important. Mobile phone is a portable device which is widely using in both the indoor and outside environments, so it is needed to be overcome to deteriorate image quality depending on environmental light source. Furthermore touch window is popular on the mobile display panel and it makes contrast loss because of low transmittance of ITO film. This paper presents the image enhancement algorithm to be embedded on image enhancement SoC. In contrast enhancement, we propose Clipped histogram stretching method to make it adaptive with the input images, while S-shape curve and gain/offset method for the static application And CIELCh color space is used to sunlight readability enhancement by controlling the lightness and chroma components which is depended on the sensing value of light sensor. Finally the performance of proposed algorithm is evaluated by using histogram, RGB pixel distribution, entropy and dynamic range of resultant images. We expect that the proposed algorithm is suitable for image enhancement of embedded SoC system which is applicable for the small-sized mobile display.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.13 no.2
• /
• pp.99-103
• /
• 2017

The primary responsibility for the oral hygiene of the disabled is usually the parents. Dental care of the disabled is early detection and recovery of lesions and continuous management. For this to be successful it is necessary to use diagnostic tool that can detect the early stages of dental caries which is difficult to detect with the naked eye. It is also important to educate and motivate the caregivers on oral hygiene management. Quantitative Light-induced Fluorescence-Digital (Billuminator, Inspektor Researh Systems BV, Amsterdam, The Netherlands), which provides overall caries inspection and visual information, can be useful for caregiver education. A 3-year-old girl who was hospitalized with Pallister-Killian syndrome, Hypothyroidism visited our clinic with chief complaint of rugged upper incisors. This girl had multiple dental caries and oral hygiene was very poor. Periodic QLF-D images were taken to provide caregiver education and oral hygiene management was improved. A 13-year-old girl with cerebral palsy visited our clinic for regular check up. Using QLF-D, we explained to the parents that there is a need for treatment of dental caries, and education of oral hygiene management was conducted. Improvement of oral hygiene in the disabled can be achieved through caregiver education. QLF-D is a diagnostic device that can detects early caries by irradiating light in the visible ray area to the teeth. It can also detects microleakage of restoration, plaque and calculus without disclosing agent. Clinicians can use the QLF-D to perform a general oral examination for the disabled. Also, QLF-D can be used to store visual information and educate caregivers. The accumulation of information using QLF-D makes it possible to provide feedback on oral care of parents, which is more advantageous for caregivers education.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.4
• /
• pp.301-309
• /
• 2015

Purpose: When the edentulous area is restored by implant prostheses, the opposing hypofunctioned teeth will receive physiologic mechanical stimuli. This study evaluated the bone changes around the maxillary teeth opposing an implant restoration installed in the mandibular posterior area. Materials and Methods: Radiographs of the opposing teeth were taken at prostheses delivery (baseline), 3 and 6 months later. A customized film holding device was fabricated to standardize the projection geometry for the serial radiographs of the opposing teeth. The gray values of the region of interest of each digital image were compared according to time. Repeated measured analysis of variance was performed at the 95% significance level. Results: The gray values of the alveolar bone around the antagonist teeth of implants increased with time. The changes in gray values of the middle area were greater than those of the crestal area. However, the gray values of the mesial and distal areas were not different. The changes in gray values were different according to the unloaded time. Conclusion: A change in bone tissue will occur if a proper physiologic load is again applied to the bone tissues around a hypofunctioned tooth.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.156-156
• /
• 2017

Most crop damages have been occurred by vermin(e.g., wild birds and herbivores) during the period between seeding and the cotyledon level. In this study, to minimize the damage by vermin and acquire the benefits such as protection against weeds and maintenance of water content in soil, immediately vinyl mulching after seeding was devised. Vinyl mulching has been generally covered with black color vinyl, that crop seeding locations cannot be detected by visible light range. Before punching vinyl, non-contact and non-destructive methods that can continuously determine the locations are necessary. In this study, a crop position detection method was studied that uses infrared thermal image sensor to determine the cotyledon position under vinyl mulch. The moving system for acquiring image arrays has been developed for continuously detecting crop locations under plastic mulching on the field. A sliding mechanical device was developed to move the sensor, which were arranged in the form of a linear array, perpendicular to the array using a micro-controller integrated with a stepping motor. The experiments were conducted while moving 4.00 cm/s speed of the IR sensor by the rotational speed of the stepping motor based on a digital pulse width modulation signal from the micro-controller. The acquired images were calibrated with the spatial image correlation. The collected data were processed using moving averaging on interpolation to determine the frame where the variance was the smallest in resolution units of 1.02 cm. For this study, the spline method was relatively faster than the other polynomial interpolation methods, because it has a lower maximum order of formulation when using a system such as the tridiagonal linear equation system which provided the capability of real-time processing. The temperature distribution corresponding to the distance between the crops was 10 cm, and the more clearly the leaf pattern of the crop was visually confirmed. The frequency difference was decreased, as the number of overlapped pixels was increased. Also the wave pattern of points where the crops were recognized were reduced.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.539-553
• /
• 1999

The purpose of this 6-months study was to compare the clinical and radiographic outcomes following guided tissue regeneration treating human mandibular Class II furcation defects with a bioabsorbable BioMesh barrier(test treatment) or a nonabsorbable ePTFE barrier(control treatment). Fourteen defects in 14 patients(mean age 44 years) were treated with BioMesh barriers and ten defects in 10 patients(mean age 48 years) with ePTFE barriers. After initial therapy, a GTR procedure was done. Following flap elevation, root planing, and removal of granulation tissue, each device was adjusted to cover the furcation defect. The flaps were repositioned and sutured to complete coverage of the barriers. A second surgical procedure was performed at control sites after 4 to 6 weeks to remove the nonresorbable barrier. Radiographic and clinical examinations(plaque index, gingival index, tooth mobility, gingival margin position, pocket depth, clinical attachment level) were carried out under standardized conditions immediately before and 6 months after surgery. Furthermore, digital subtraction radiography was carried out. All areas healed uneventfully. Surgical treatment resulted in clinically and statistically equivalent changes when comparisons were made between test and control treatments. Changes in plaque index were 0.7 for test and 0.4 for control treatments; changes in gingival index were 0.9 and 0.5. In both group gingival margin position and pocket depth reduction was 1.0mm and 3.0mm; clinical attachment level gain was 1.9mm. There were no changes in tooth mobility and the bone in radiographic evaluation. No significant(p${\leq }$0.05) difference between the two membranes could be detected with regard to plaque index, gingival index, gingival margin position, pocket depth, and clinical attachment level. In conclusion, a bioabsorbable BioMesh membrane is effective in human mandibular Class II furcation defects and a longer period study is needed to fully evaluate the outcomes.