• Journal of Communications and Networks
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• 제12권5호
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• pp.433-441
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• 2010

Multihop transmission is a promising technique that helps in achieving broader coverage (excellent network connectivity) and preventing the impairment of wireless channels. This paper proposes a cluster-based multihop wireless network that makes use of the advantages of multihop relaying, i.e., path loss gain, and partial relay selection in each hop, i.e., spatial diversity. In this partial relay selection, the node with the maximum instantaneous channel gain will serve as the sender for the next hop. With the proposed protocol, the transmit power and spectral efficiency can be improved over those in the case of direct transmission and conventional multihop transmission. Moreover, at a high signal-to-noise ratio (SNR), the performance of the system with at least two nodes in each cluster is dependent only on the last hop and not on any of the intermediate hops. For a practically feasible decode-and-forward relay strategy, a compact expression for the probability density function of the end-to-end SNR at the destination is derived. This expression is then used to derive closed-form expressions for the outage probability, average symbol error rate, and average bit error rate for M-ary square quadrature amplitude modulation as well as to determine the spectral efficiency of the system. In addition, the probability of SNR gain over direct transmission is investigated for different environments. The mathematical analysis is verified by various simulation results for demonstrating the accuracy of the theoretical approach.

• 대한치과보철학회지
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• 제60권4호
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• pp.412-419
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• 2022

부분 무치악 환자의 구강회복을 위해서는 임플란트를 이용한 치료 방법이 널리 활용되고 있다. 임플란트를 이용한 치료방법은 크게 고정성 임플란트 보철물과 가철성 임플란트 보철물로 나뉠 수 있으며, 골 흡수가 심한 환자의 경우 심미적이고 경제적인 이점을 갖는 가철성 임플란트 보철물이 치료 옵션으로 활용될 수 있다. 특히 소수의 임플란트에 Milled-bar와 부가적인 유지장치를 이용한 보철물 제작 시, 임플란트 고정체 간의 연결고정 효과 및 의치의 유지력과 안정성이 증가할 수 있다. 또한 의치상을 통한 구순 지지를 통해 심미적인 보철물 제작이 가능하다. 본 증례의 환자는 상악골의 심한 골 흡수를 동반한 소수의 잔존치를 갖는 부분 무치악 환자로 전치부 및 소구치부위에 임플란트를 3개 식립 후 캐드캠을 이용하여 제작된 Milled-bar와 ADD-TOC 어태치먼트를 이용한 임플란트 부분 피개의치로 치료하였다. 그 결과 어태치먼트를 이용한 clasp 제거 및 의치상을 이용한 구순 지지를 통해 심미성을 높였으며, Milled-bar를 통한 교합력 지지와 의치 안정성을 확보하였다. 또한 환자의 이물감 해소를 위해 구개부 피개량을 줄인 금속 구조물의 피개의치를 제작하였으며, 만족스러운 결과를 얻었기에 보고하는 바이다.

• 전기학회논문지P
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• 제52권1호
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• pp.14-19
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• 2003

The effect of the Pt electrode and the $Pt-IrO_2$ hybrid electrode on the performance of ferroelectric device was investigated. The modified Pt thin films with non-columnar structure significantly reduced the oxidation of TiN diffusion barrier layer, which rendered it possible to incorporate the simple stacked structure of Pt/TiN/poly-Si plug. When a $Pt-IrO_2$ hybrid electrode is applied, PZT thin film properties are influenced by the thickness and the partial coverage of the electrode layers. The optimized $Pt-IrO_2$ hybrid electrode significantly enhanced the fatigue properties of the PZT thin film with minimal leakage current.

• 대한치과의사협회지
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• 제54권6호
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• pp.448-456
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• 2016

Dental care is becoming more available on the NHI(National Health Insurance) in Korea. Especially, complete denture, partial denture, dental scaling, and dental implant has been applied by NHI from 2012 to 2014. Although, the entire nation is not eligible for the benefit now, the more dental coverage of NHI is extended, the more regulaition is tightened. Essential documents for proof of correctness of dental treatment covered by NHI are dental records and the receipt book. Summary of regal regulation about them is as follows 1. Chief complaints of patients, diagnosis, progress, and act of treatment, drugs and materials of treatment, doctor's sign, date and hour should be placed accurately on dental record 2. Dental clinic should collect patients sharing of the dental cost covered by NHI. 3. Dental clinic should keep the receipt as proof of purchase of dental drugs or materials.

• Archives of Reconstructive Microsurgery
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• 제19권1호
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• pp.37-45
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• 2010

Purpose: First introduced by Buncke and Rose in 1979, the neurovascular partial $2^{nd}$ toe pulp free tissue transfer has been attempted to reconstruct posttraumatic finger tip injuries. Although some surgeons prefer other reconstructive methods such as skin graft and local flap, we chose the partial $2^{nd}$ toe pulp flap owing to its many advantages. We report three successful surgical cases in which the patients had undergone this particular method of reconstruction. Methods: We retrospectively examined three cases of fingertip injury patients due to mechanical injury. Bone exposure was seen in all three cases, All had undergone partial toe pulp free flap for soft tissue defect coverage. Results: All flaps survived without any complications such as partial necrosis, hematoma or dehiscence. Although tingling sensation has returned in both cases, two-point discrimination has not returned yet. Currently no patient is complaining of any pain which gradually improved during their course of recuperation. All stitches were removed on postoperative 2 weeks. Patients are satisfied with the final surgical result and there are no signs of any edema or hematoma. Conclusion: The homodigital reconstruction of finger tip injury using the partial $2^{nd}$ toe pulp flap has numerous advantages compared to other reconstructive modalities such as its resistance to wear and tear and in that it provides a non-slip palmar digital surface. However it requires microsurgery which may not be preferred by surgeons. Advanced age of the patient can be a relative contraindication to this approach since atheromatous plaque from the donor toe can compromise flap circulation after surgery. We report three successful cases which patient age was considered appropriate. Further investigation with a larger number of cases and long term follow-up is deemed necessary.

• 대한치과보철학회지
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• 제19권1호
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• pp.7-16
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• 1981

The technology of precision attachments has developed at such a pace that from a very few T-shaped attachments and bar attachments from the years 1915 to 1935 since removable bridge utilizing a T-shaped intracoronal attachment was constructed by Dr. Herman E.S. Chayes in 1906. There are now more than 120 models of the most diversified designs, ready made or laboratory fashioned. In 1971, 126 attachments were listed and classified by Mensor in his E M Attachment Selector. This selector consists of five charts giving specifications as to type, vertical dimensions, application, type of resilience, size of movement, type of retention and type of material and alloy. Thus the E M Attachment Selector is a useful guide for dentists to choose the attachment for his patients. But dentists should apply the attachment in each patient's case according to an accurate diagnosis and treatment plan. This paper is a case report of removable partial dentures utilizing CSP, PD and Bar attachment on a patient who needed full mouth reconstruction. Patient has right first, second molar and left first molar on the upper arch and also left first molar, first premolar and right canine on the lower arch. (Fig. 5)All remaining teeth are relatively healthy in their supporting tissues. On upper arch, ring shape CSP attachment was designed on left first molar and modified ring shape CSP attachment was designed on right first and second molar as the direct retainer of the removable partial denture. Full palatal coverage was used as the major connector in this case. (Fig. 23) On lower arch, author first splinted with a fixed bridge between left first molar and second premolar and a splint bar between left second premolar and right canine. (Fig. 11) A lower removable partial denture in which was designed with an Aker clasp on the left first molar and a PD attachment on .the right canine was constructed. (Fig. 17) This denture could get additional support from anterior splint bar. After both removable partial dentures were delivered to the patient (Fig. 26), author evaluated function of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of this case was excellent.

• Archives of Reconstructive Microsurgery
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• 제20권1호
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• pp.1-7
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• 2011

The aim of extremity reconstruction has focused on early wound coverage and functional recovery but rarely aesthetics. As the quality of life improves, however, the request for aesthetics has been growing. The authors has conducted retrospective reviews on the 86 cases that had extremity reconstruction using free flap, considering the characteristics of parts that had been assessed in primary operation between May 1996 and December 2010. Aesthetic grading was performed in four categories; color, texture, contour and marginal scar. Recipient sites were 42 hands, 19 feet, 14 lower extremities excluding feet and 10 upper extremities apart from the hand. Types of free flap were 16 latissimus dorsi free flaps, 13 anterolateral thigh free flaps, 12 dorsalis pedis free flaps, 8 transvers rectus abdominis free flaps, 7 gracillis free flaps, and 5 superficial temporal fascia free flaps. Total flap necrosis was seen in 8 cases(9.3%) and partial necrosis in 5 cases(5.8%). Secondary revision was done in 24 cases(27.9%) and the most common revision, debulking was done in 14 cases(16.3%). The authors has considered cosmetic aspects along with wound coverage and functional recovery in primary reconstruction. The results of aesthetic grading was 16.2 out of 20, and the secondary revision rate was reduced.

• Archives of Reconstructive Microsurgery
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• 제17권1호
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• pp.28-35
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• 2008

The purpose of this study was to present the clinical analysis of the results of lateral arm free flap for small sized and infected diabetic foot ulcer around toes. From May 2006 to December 2007, Seven patients were included in our study. Average age was 52.8 years, six were males and one was female. All had infected diabetic foot ulcer and had exposures of bone or tendon structures. Ulcers were located around great toe in four patients, 4th toe in one and 5th toe in two. Three patients had osteomyelitis of metatarsal or phalanx. After appropriate control of infection by serial wound debridement and intravenous antibiotics, lateral arm flap was applied to cover remained soft tissue defects. Posterior radial collateral artery of lateral arm flap was reanastomosed to dorsalis pedis artery of recipient foot by end to side technique in all cases in order to preserve already compromised artery of diabetic foot. All flaps were designed over lateral epicondyle to get longer pedicle and averaged pedicle length was 8 cm. Two cases were used as a sensate flap to achieve protective sensation of foot. All flaps survived and provided satisfactory coverage of soft tissue defects on diabetc foot ulcers. All patients could achieve full weight-bearing ambulation. No patients has had recurrence of infection, ulceration and further toe amputations. There were three complications, a delayed wound healing of flap with surrounding tissue, a partial peripheral loss of flap and a numbness of forearm below donor site. All patients were satisfied with their clinical results, especially preserving their toes and could return to the previous activity levels. Lateral arm free flap could be recommend for infected diabetic foot ulcers around toes, to preserve toes, coverage of soft tissue defect and control of infection with low donor site morbidity.

• Archives of Reconstructive Microsurgery
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• 제25권2호
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• pp.37-42
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• 2016

Purpose: Soft tissue coverage of the distal leg and ankle region represents a surgical challenge. Beside various local and free flaps, the perforator flap has recently been replaced as a reconstructive choice because of its functional and aesthetic superiority. Although posterior tibial artery perforator flap (PTAPF) has been reported less often than peroneal artery perforator flap, it also provides a reliable surgical option in small to moderate sized defects especially around the medial malleolar region. Materials and Methods: Seven consecutive patients with soft tissue defect in the ankle and foot region were enrolled. After Doppler tracing along the posterior tibial artery, the PTAPF was elevated from the adjacent tissue. The average size of the flap was $28.08{\pm}9.31cm^2$ (range, 14.25 to $37.84cm^2$). The elevated flap was acutely rotated or advanced. Results: Six flaps survived completely but one flap showed partial necrosis because of overprediction of the perforasome. No donor site complications were observed during the follow-up period and all seven patients were satisfied with the final results. Conclusion: For a small to medium-sized defect in the lower leg, we conducted the close-by islanded PTAPF using a single proper adjacent perforator. Considering the weak point of the conventional propeller flap, this technique yields much better aesthetic results as a simple and reliable technique especially for defects of the medial malleolar region.

• Archives of Plastic Surgery
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• 제45권1호
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• pp.62-68
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• 2018

Background Amputation is commonly performed for toe necrosis secondary to peripheral vascular diseases, such as diabetes mellitus. When amputating a necrotic toe, preservation of the bony structure is important for preventing the collapse of adjacent digits into the amputated space. However, in the popular terminal Syme's amputation technique, partial amputation of the distal phalanx could cause increased tension on the wound margin. Herein, we introduce a new way to resect sufficient bony structure while maintaining the normal length, based on a morphological analysis of the toes. Methods Unlike the pulp of the finger in the distal phalanx, the toe has abundant teardrop-shaped pulp tissue. The ratio of the vertical length to the longitudinal length in the distal phalanx was compared between the toes and fingers. Amputation was performed at the proximal interphalangeal joint level. Then, a mobilizable pulp flap was rotated $90^{\circ}$ cephalad to replace the distal soft tissue defect. This modified toe fillet flap was performed in 5 patients. Results The toe pulp was found to have a vertically oriented morphology compared to that of the fingers, enabling length preservation through cephalad rotation. All defects were successfully covered without marginal ischemia. Conclusions While conventional toe fillet flap coverage focuses on the principle of length preservation as the first priority, our modified method takes both wound healing and length into account. The fattiest part of the pulp is advanced to the toe tip, providing a cushioning effect and enough length to substitute for phalangeal bone loss. Our modified method led to satisfactory functional and aesthetic outcomes.