• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.367-376
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• 2007

In this paper, we introduce an application-specific and adaptive power management technique for portable systems that support dynamic voltage scaling (DVS). We exploit both the idle time of multitasking systems running soft real-time tasks as well as memory- or CPU-bound code regions. Detailed power and execution time profiles guide an adaptive power manager (APM) that is linked to the operating system. A post-pass optimizer marks candidate regions for DVS by inserting calls to the APM. At runtime, the APM monitors the CPU's performance counters to dynamically determine the affinity of the each marked region. for each region, the APM computes the optimal voltage and frequency setting in terms of energy consumption and switches the CPU to that setting during the execution of the region. Idle time is exploited by monitoring system idle time and switching to the energy-wise most economical setting without prolonging execution. We show that our method is most effective for periodic workloads such as video or audio decoding. We have implemented our method in a multitasking operating system (Microsoft Windows CE) running on an Intel XScale-processor. We achieved up to 9% of total system power savings over the standard power management policy that puts the CPU in a low Power mode during idle periods.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.8-18
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• 2013

Purpose : The purpose of this study was to find and categorize the various magnetic resonance imaging (MRI) findings of spinal metastases that correlate with the type of primary cancer. Materials and Methods: We retrospectively reviewed gadolinium-enhanced magnetic resonance images of 30 patients with 169 spinal metastatic lesions from lung cancer (n = 56), breast cancer (n = 29), colorectal cancer (n = 20), hepatocellular carcinoma (HCC) (n = 17), and stomach cancer (n = 47). The size, location, extent of invasion, signal intensity, margin, enhancement pattern, and osteoblastic or osteolytic characteristics of each metastatic tumor were analyzed. Results: The metastatic lesions from HCC were larger than those from the other primary tumors (P < 0.05) except for colorectal cancer (P = 0.268). Well-defined metastatic tumor margins were more frequently seen in lung cancer and breast cancer (P < 0.01). All but HCC showed a tendency to invade the vertebral body rather than the posterior elements (P < 0.02). Colorectal cancer and HCC showed a tendency toward extraosseous invasion without statistical significance. HCC showed a characteristic enhancement pattern of 'worms-in-a-bag'. Rim enhancement with a sclerotic center was only seen in spinal metastases from stomach cancer. Conclusion: Despite many overlapping imaging features, spinal metastases of various primary tumors display some characteristic MRI findings that can help identify the primary cancer.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.399-408
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• 1995

The purpose of this study was to obtain information on the clinical and radiographic features of the dentigerous cysts in the jaws. For this study, the authors examined and analysed the clinical records and radiographs of 233 patients who had lesions of dentigerous cyst diagnosed by clinical and radiographic or histopathological examinations. And the obtained results were as follows: 1. Dentigerous cysts occurred the most frequently in the 2nd decade(38.2％) and occurred more frequently in males(67.4％) than in females(32.6％). 2. The most common clinical symptom was swelling of the jaw(33.9％), and the lesions were treated by the method of surgical removal. 3. The type of lesions was mainly observed as central type(72.5％), and size of the lesion was most frequently observed 2 - 2.9cm in the widest length. 4. The lesions were most frequently observed well-defined outline with hyperostotic border(49.8％), and smooth margin(73.4％), and homogeneous lesional radiolucency(79.4％). 5. Cortical thinning and expansion of the lesions(82.0％) were observed, and their direction were most frequently observed toward buccal side(64.0％). 6. The effect on the causative tooth were observed as tooth displacement(41.2％) and delayed root development(l9.3％), and the distance between cemento-enamel junction and lesional wall attachment of the causative tooth was mainly observed as below 2mm(79.6％). 7. The effect on the adjacent tooth were observed as loss of lamina dura(66.8％), root resorption(33.9％), and tooth displacement(31.5％). 8. The effects on the adjacent anatomic structures were observed as displacement of the mandibular canal(46.5％) and maxillary sinus or nasal cavity(72.2％).

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.549-561
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• 2005

이 연구의 목적은 새로이 제작된 chitosan-poly(L-lactic acid)(PLLA) 다층 다공성 차폐막의 생체적합성 및 골세포활성도 및 골재생능을 평가하는 것이다. 제작된 차폐막을 24 well에 넣고 clonal osteoblast-like cell line(MC3T3-E1)을 접종한 군을 실험군으로, 차폐막을 사용하지 않은 대조군으로 하였다. 배양 1일, 7일 및 14일째에 각 well에서 세포수를 측정하였다. 주사전자현미경을 이용하여 차폐막에 부착된 세포의 형태관찰을 시행하였다. RNA 추출 및 RT-PCR을 실시한 후, agarose gel상에서 전기영동하여 조골세포 표식자인 collagen type I(COL), osteopontin(OP) 및 osteocalcin(OC) mRNA의 발현을 관찰하였다. 제작된 매트릭스의 생체적합성 및 골재생능을 관찰하기 위하여 백서의 두개골에 직경 8mm의 원형 결손부를 형성한 후 차폐막을 이식한 군을 실험군으로, 아무 것도 넣지 않은 군을 대조군으로 하여 4주 경과 후 실험동물을 희생시킨 후 조직학적관찰을 시행하였다. 시간경과에 따른 부착세포수 관찰결과, 배양 14일까지 조골세포의 수가 지속적으로 증가하였고, 주사전자현미경으로 세포의 형태 관찰결과, 배양된 세포들은 중층의 형태로 성장하면서 시간경과에 따라 세포가 응집되는 양상을 나타내었다. 관찰 기간동안 COL, OP, 및 OC mRNA의 발현이 관찰되어 배양 전 기간동안 조골세포의 형질이 잘 유지되고 있음을 알 수 있었다. 백서 두개골 결손부에 이식된 차폐막은 염증반응 없이 주위 조직과 우수한 생체적합성을 나타내었으며, 차폐막을 이식하지 하지 않은 대조군에 비해 높은 신생골 형성을 나타내었다. 이상의 관찰결과로 새로이 제작된 chitosan-PLLA 차폐막은 우수한 생체적합성 및 골재생능을 나타냄을 알 수 있었으며, 향후 이를 골조직 재생 및 치주조직유도재생 분야에 응용될 수 있을 것으로 생각된다.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.192-194
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• 2002

The goal of surgery of chronic osteomyelitis is removal of dead bone and achieving a viable and vascular environment. During saucerization, the sequestrum could be checked and resected completely. But it can causes vascular injury by massive soft tissue dissection in saucerization of chronic osteomyelitis. Recently, we experienced medulloscopy in the treatment of chronic osteomyelitis and it is possible for us to visualize the sequestrum, to do complete resection of dead bone and to reduce vascular injury during operation.

• Journal of the Korean Ceramic Society
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• v.45 no.10
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• pp.625-630
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• 2008

In the bone cement composed of dense granules of $\beta-Ca_3(PO_4){_2}(\beta-TCP)$ and $Ca(H_2PO_4){_2}H_2O$, the compressive strength, setting time and temperature rise were measured to observe the degradation of cement with respect to the stored days before setting. Decreases of compressive strength and temperature rise were observed, while setting time increased with respect to the stored days. The similar trends were repeated with the increase of temperature of storage. Such a change virtually meant the fading of the character of cement and it took place only when the two starting materials were mixed during storage. The degradation could be mitigated taking advantage of granular $\beta$-TCP instead of powdery one. The formation of $CaHPO_4$, which resulted from reaction with ambient humidity, was attributed to the degradation observed during storage. Dependence of the degradation behavior on mixing and temperature during storage was discussed in terms of the driving force for reaction of cement.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.889-896
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• 1996

Aggressive revascularization of the ischemic lower extremities in atherosclerotic occlusive diseases or acute embolic arterial occusion due to cardiac valvular disease by thromboembolectomy or an arterial by- pass operation has been advocated by some authors. To evaluate clinical pattern and operative outcome of the ischemic lower extremity, surgical experience in 101 patients who were admitted to Dong-A Univer- sity Hospital between March 1990 and August 1995 was analyzed. The patients were 92 males and 9 females ranging fro 25 to 87 years of age. The underlying causes of arterial occlusive disease were atherosclerotic obliterances in 54 case, Buerger's disease in 20 cases, thromboembolism in 24 cases, vascular trauma in 3 cases and pseudoaneurysm in 3 cases. - The major arterial occlusive sites of atherosclerotic obliterance were femoral artery in 30 cases, iliac artery in 23 cases, popliteal artery in 10 cases, distal aorta in 6 cases and the major arterial occlusive sites of Buerger's disease were posterior tibial artery in 14 cases, anterior tibial artery in 8 cases, popliteal artery in 5 cases. The operative procedures of arterial occlusive disease were bypass graft operation in 61 cases, thromboembolectomy in 21 cases, sympathectomy in 20 cases. Arterial bypass operations with autogenous or artificial vascular prosthesis were done in 61 cases which Included femoro-popliteal bypass in 21 cases, femoro-femoral bypass in 15 cases, axillo-bifemoral bypass in 7 cases, aorto-bifemoral with inverted Y-gr ft In 3 cases, femoro-profundafemoral bypass in 3 cases, popliteo-tibial bypass in 2 cases, aorto-iliad bypass in 1 case Over all postoperative patency rates were 83.6 oyo at 1 year, 75.5% at 3 years and limb salvage rate was 86.8 oyo . Six patients died in the hospital following vascular surgery for ischemic lower extremities, although the causes of death were not directly related to the vascular reconstructive operative proccedures. The leading causes of death were in the order of multiple organ failure, acute renal failure, and sepsis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.123-131
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• 2007

Introduction: Distraction osteogenesis is widely used as for bone lengthening in patients with maxillofacial deformity and alveolar bone atrophy. One of the major problems in distraction osteogenesis is long consolidation period for 2-3 months, in which the devices have to be fixed on the bone to prevent relapse. It results in scar formation on the face, disturbance of mastication and speech. This study was performed to evaluate the stimulating effect of pulsed electromagnetic field on the early bone consolidation in distraction osteogenesis. Materials and methods: Total 10 rabbit were used (5 for control group, 5 for experimental group). A vertical osteotomy in the mandibular body was performed and the distraction device was fixed. After 5 days distraction was done 1mm per a day for 7 days. A pulsed electromagnetic field (38 Gauss, 60 Hz) was applied for 8 hours per day and it continued for 5 days immediately after distraction in the experimental group. Both groups were sacrificed after 2 weeks. Histological specimens with H&E and Masson Trichrome staining were made and histomorphometrically analysed with image analyser. Results: The device for distraction osteogenesis was displaced in one animal for each group, therefore, only four animals in both groups were evaluated. In both groups, a new bone formation was observed in the distracted area after 2 weeks. The bone formation was enhanced in the experimental groups ($31.76{\pm}8.68%$) compared with control group ($9.94{\pm}3.23%$), its difference was statistically significant (p<0.001). Conclusion: This study suggests that electrical stimulation with electromagnectic field may be effective in the early bone formation after distraction osteogenesis. Further studies with large number of animals are needed before clinical application.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.222-228
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• 2010

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.70-76
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• 2000

Congenital biliary atresia with progressive sclerosis of the intra- and extra-hepatic duct system occurs in 1 : 10,000 live births, and has a poor prognosis with an expected survival of less than 5 years. Etiology of biliary atresia is unclear, however, it is believed a genetic or developmental cause. The clinical characteristics include pronounced jaundice, hepatosplenomegaly, pruritus, steatorrhea, xanthomas, growth retardation, portal hypertension, bleedings, ascites and respiratory infections. Oral manifestations have seldom been reported in patients with biliary atresia, but there may be enamel hypoplasia, delayed tooth eruption, and green teeth. Early diagnosis and surgical intervention have decreased morbidity. returned growth and development to normal and improved the prognosis for survival. Authors report the clinical and radiologic characteristics, proper managements about two cases with biliary atresia.