• Journal of Korean Foot and Ankle Society
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• v.17 no.2
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• pp.115-120
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• 2013

Purpose: Calcaneal lengthening osteotomy is one option for the treatment of symptomatic flexible flatfoot in adults. The aim of the study was to evaluate the short term clinical and radiologic results and analyze its complications. Materials and Methods: Twelve feet who had undergone calcaneal lengthening osteotomy without flexor digitorum longus transfer between December 2009 and July 2011 were included. The mean age was 40.6 years (23~75 years). The mean followup was 17.3 months (13~25 months). Clinical outcome were assessed using American Orthopadics Foot ans Ankle Society (AOFAS) score and visual analogue scale (VAS) for pain. Four radiologic parameters were measured from weightbearing radiographs to evaluate the difference between preoperatively and postoperatively measures. To analyze the complications, calcaneocuboid joint subluxation and degenerative change were measured postoperatively. Results: The mean AOFAS score improved from 55.3 points preoperatively to 82.2 points at lastest follow-up (p=0.000). The mean VAS improved from 6.3 points preoperatively to 3.2 points postoperatively (p=0.002).All radiologic parameters, the mean talonavicular coverage angle on AP view, the mean talo-1st metatarsal angle on AP and lateral view and the mean calcaneal pitch angle, significantly improved after calcaneal lengthening osteotomy. Nine feets (75%) were shown the degenerative change in the calcaneocuboid joint at latest follow-up radiographs. Conclusion: Calcaneal lengthening osteotomy for the symptomatic flexible flatfoot in adults produced significant improvement in clinical and radiologic parameters, but calcaneocuboid joint osteoarthritis occurred postoperatively remained a major problem.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.454-462
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• 2016

portable white space device(WSD) obeying the Korean regulations of TV white space(TVWS) can cause harmful interference to a digital TV receiver residing at the same pixel around the edge of the digital TV service coverage for the case with a changed propagation environment. In order to solve this problem, we propose a method to allocate the resource of a hybrid WSD based on TVWS geo-location DB with spectrum sensing. Using the received power of digital TV signal through the spectrum sensing, a hybrid WSD can calculate the maximum permitted EIRP based on location probability. Based on the accurate allocation method proposed in this paper, it is possible to satisfy the Korean TVWS regulations and to eliminate the harmful interference to TV receivers nearby the hybrid WSD.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.143-150
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• 1984

This paper is a study on effectiveness of weight in analytical positioning of oblique photography. Oblique photographies are more economical than normal photographies as it has a larger ground coverage and as it can be applied in situations where objects of interest are difficult to be approached. But the comparatively complex methods involved, present a problem in obtaining the desired results. In view of this fact, analytical rectification was applied in normalizing the oblique photographs. As oblique photographies are extensively used in slops and mountainous regions, a number of difficulties are encountered during the control surveying. The photocoordinates of the oblique photographs, taken at $30^{\circ}$, were weighted during rectification. They were weighted as inversely proportionate to the derived formular of ${\gamma}_y=f{\cdot}tan{\frac{\theta}{2}}+y_a$, the distance of each point from the isocenter along the Y axis. By applying the weights, coordinates errors conld be reduced and the error difference between oblique and normal photographs could be reduced upto 53.2%.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.138-140
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• 2002

The spinal cord dose is the one of the limiting factor for the radiation treatment of the head & neck (H&N) or the thorax region. Due to the fact that the cord is the elongated shaped structure, it is not an easy task to maintain the cord dose within the clinically acceptable dose range. To overcome this problem, the spinal cord partial block technique (PBT) with the dynamic Multi-Leaf Collimator (dMLC) has been developed. Three dimension (3D) conformal beam directions, which minimize the coverage of the normal organs such as the lung and the parotid gland, were chosen. The PBT field shape for each field was designed to shield the spinal cord with the dMLC. The transmission factors were determined by the forward calculation method. The plan comparisons between the conventional 3D conformal therapy plan and the PTB plan were performed to evaluate the validity of this technique. The conformity index (CI) and the dose volume histogram (DVH) were used as the plan comparison indices. A series of quality assurance (QA) was performed to guarantee the reliable treatment. The QA consisted of the film dosimetry for the verification of the dose distribution and the point measurements. The PBT plan always generated better results than the conventional 3D conformal plan. The PBT was proved to be useful for the H&N and thorax region.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.207-214
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• 2011

In this paper, using Zigbee-based wireless sensor networks and Lego MindStorms NXT robot, a remote monitoring and navigation system for mobile robot has been developed. Mobile robot can estimate its position using encoder values of its motor, but due to the existing friction and shortage of motor power etc., error occurs. To fix this problem and obtain more accurate position of mobile robot, a ultrasound module on wireless sensor networks has been used in this paper. To overcome disadvantages of ultrasound which include straightforwardness and narrow detection coverage, we rotate moving node attached to mobile robot by $360^{\circ}$ to measure each distance from four fixed nodes. Then location of mobile robot is estimated by triangulation using measured distance values. In addition, images are sent via a network using a USB Web camera to smart phone. On smart phones we can see location of robot, and images around places where robot navigates. And remote monitoring and navigation is possible by just clicking points at the map on smart phones.

• Journal of Internet Computing and Services
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• v.2 no.1
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• pp.1-11
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• 2001

Though it is proposed to use Petri net or dynamic FSM methods for the generation of test sequences on some specific protocols, those methods ere unavailable on the cases where the protocol allows faults processing or includes paths in looping which cause errors or endless looping by the explosion of states. The determination of test coverage on the protocol software that has been designed and implemented is difficult by the reason of development periods, technical solutions to support and also economical limitations. It is suggested to generate timely protocol software test sequences on the basis of regular expressions covering the functions of protocol. With this regular expression method, the 38 test sequences of Q.2971 protocol has been generated and also minimized the endless looping problem when dynamic test suites are used by simplifying the test path expressions that denotes loops, According to the works, the suggested method is confirmed as simple and easy compare to the other dynamic test sequence generation techniques. Moreover. the method to search an optional test path whether it Is included or not in the regular path expression is reviewed.

• Archives of Reconstructive Microsurgery
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• v.7 no.2
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• pp.165-174
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• 1998

Large soft tissue defect of the ankle and foot can present a difficult reconstructive problem to the surgeon. Local musculocutaneous, local fasciocutaneous or free flap is usually the first choice for providing soft tissue coverage. However, in certain situations, local flaps from the same leg and free flap may not be suitable. These include extensive soft tissue injury, where no suitable recipient vessels can be found, previous local fasciocutaneous flap or free flap failure. In such cases, we have utilized the septocutaneous(fasciocutaneous) branch flap of posterior tibial artery from the opposite healthy limb. We present 5 cases of cross leg flaps, which have been modernized with current understanding of vascular anatomy and current fixation technology. All cross leg flaps were based on the axial blood supply of the fasciocutanous branch of the posterior tibial artery. Cross-clamping with bowel clamp was used to create intermittent periods of ischemia. Adjacent lower extremity joints were exercised during the periods of attachment. The results have been quite encouraging. We conclude that the cross leg flap using septocutaneous flap and cast immobilization can be successfully and expeditiously used to cover defects of the ante and foot.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.735-741
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• 2013

Background The prosthetic dura is an essential element in the protection of the cranial parenchyma and prevention of cerebrospinal fluid leakage. Although prosthetic dura are widely used in neurosurgery, they occasionally provoke infection, which can be a major concern after neurosurgical treatment. However, removal of the prosthetic dura carries a risk of brain parenchyma injury and cerebrospinal fluid leakage. The salvage of infected prosthetic dural material has not been adequately addressed in the literature. In this study, we demonstrate the value of the combination of a meticulous surgical debridement of necrotic tissue and simultaneous muscle free flap for intractable postoperative epidural abscess without removal of the infected prosthetic dura. Methods Between 2010 and 2012, we reviewed the data of 11 patients with persistent infection on the prosthetic dura. The epidural infections each occurred after a neurosurgical procedure, and there was soft tissue necrosis with the disclosure of the underlying prosthetic dura and dead bone around the scalp wound. To salvage the infected prosthetic dura, meticulous debridement and a muscle free flap were performed. Results All 11 patients experienced complete recovery from the complicated wound problem without the need for further surgical intervention. No signs of prosthetic dural infection were observed during the mean follow-up period of 11 months. Conclusions The combination of a meticulous surgical debridement and coverage with a muscle free flap is an effective treatment for salvage of infected prosthetic dura.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.394-400
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• 2018

A heterogenous network is the one of key technologies for 5G, where one cell is divided into small cells in order to extend coverage and support high data rates. Divided cells aggravates the intercell interference problem as the cell edge increases. In order to avoid the intercell interference, it is the best to allocate the different spectrum for each cells. However, it also decreases the spectral efficiency. Therefore, the trade-off between the spectral efficiency gain and the signal quality loss by the interference should be considered for an efficient spectrum sharing in the heterogenous network. The adaptive modulation is the method to change the transmitted bit according to the channel quality, which is adopted as the standard in the most practical communication systems. It should be considered to applied the performance analysis into the practical systems. In this paper, the overall cell data rates is analyzed for the heterogenous network under the adaptive modulation. The Monte Carlo simulation results verify the correctness of the analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.6
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• pp.903-909
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• 2018

In December 2017, the world's first LTE-R for 250km/h high-speed railway was commercialized with the opening of Wonju-Gangneung high-speed railway. LTE-R has many advantages such as voice and video call, high-speed data transmission, coverage redundancy and DU redundancy. But it requires efficient use of radio resources because of a limited bandwidth of 10MHz for UL and DL, respectively. The existing unicast scheme has limited high frequency efficiency so when the number of users increases, service is limited due to the network load, which could be a problem for LTE-R in terms of stability and reliability. On the other hand, the multicast scheme via eMBMS can provide stable service even if the number of video users is high. This paper derives the number of unicast scheme users considering the LTE-R network with LAB test and calculation result, and proposes implementation plans and considerations for eMBMS commercialization on LTE-R.