• Journal of Preventive Medicine and Public Health
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• v.41 no.4
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• pp.255-264
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• 2008

Objectives: This study adopted a qualitative method to explore the layman's beliefs and experience concerning high blood pressure and its management in order to develop a strategy to increase adherence to proper medical treatment. Methods: Semi-structured interviews that focused on personal experiences with hypertension and its management were conducted with 26 hypertensive patients. The participants were selected according to a BP above 140/90 mmHg (hypertension stage 1), based on the seventh report of the Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure (JNC-VII). The interviews lasted for approximately 30 minutes (range: 20-60 minutes). The resulting questions were formulated into open-ended questions. The interview questionnaire was composed 17 items to examine non-adherence to treatment and 19 items to examine adherence to treatment. Results: Most participants recognized that the direct cause of high blood pressure was unhealthy behavior rather than inheritance. Thus, the hypertensive patient believed they could recover their blood pressure to a normal level through removing the direct cause of hypertension (weight reduction, diet, exercise) instead of taking drugs. The reasons for these statements were that the drugs for controlling hypertension are not natural or they are artificial, and they may have side effects, and drugs are not treatment for the root cause of hypertension. Most of the hypertensive patients chose to manage their behaviors as soon as they knew their blood pressure was high. Therefore, we should not divide the subjects into two groups according to their taking drugs or not, but they should be divided into two groups according to their willingness or not to manage their condition. Conclusions: For developing a strategy for an individual approach to hypertension management, we need to develop a client-centered attitude and strategy. That is, we need to tailor our approach to individual cases to avoid generalizations and stereotyping when developing an adherence increasing strategy.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.1
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• pp.39-46
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• 1997

The pasteurization of bone tumor shows necrosis of tumor tissue and it is used widely as one of the options of limb salvage operation. However malignant tumors of the extremities commonly involve major neurovascular structures and pasteurization of this structure will make limb salvage operation much easier and safer than autogenous vein graft or artificial vessel graft. So the purpose of this study is to evaluate that the pasteurization can be applied in the limb salvage surgery of malignant tumor involving major vessels by means of studying the patency of pasteurized femoral vessels of the dogs. The right femoral arteries of 5 to 7 mm in diameters and veins of 7 to 10 mm in diameters of five dogs were pasteurized with sterile $60^{\circ}C$ saline for 30 minutes. Contralateral femoral vessels were evaluated for the control study. After one month, the changes in the pasteurized femoral vessels were evaluated by physical examinations, femoral angiography, gross findings, and pathologic findings on the each side. One month after pasteurization, the pulse of the femoral and popliteal arteries was palpated with normal tone on the each side of the all five experimental animals, and there was no gross swelling or necrotic changes in the legs. Femoral angiography showed a good patency of femoral and popliteal arteries. On the gross examinations at time of sampling of the specimen for the pathologic examinations, there was a good patency of femoral artery and vein, and mild fibrous adhesion was noted around the pasteurized femoral vessels. On the pathologic examinations, the more fibrotic adhesion and neocapillarization were noted in the outer layer of adventitia of the pasteurized femoral arteries and veins than the control sides. The vascular lumina were also patent in all cases. With these results, we suggest that the malignant tumor of the extremity involving major vessels is possibly treated by the limb salvage operation using the pasteurization of the involved vessels.

• Journal of TMJ Balancing Medicine
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• v.6 no.1
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• pp.1-4
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• 2016

We investigated the potential of electromyography (EMG) for diagnosing imbalance in the temporomandibular joint (TMJ) to apply functional cerebrospinal therapy (FCST). The electromyography signals were measured in the sternocleidomastoid muscle (SCM) in patients with temporomandibular disorder (TMD) while a FCST specialist conducted a restricted cervical rotation test. In addition, we also observed the changes in the electromyography signals according to pre-treatment or treatment with a TMJ balancing appliance (TBA), a customized TMJ balancing appliance (CBA), or a CBA with one paper bar. The right SCMs of the two patients with right TMJ imbalance had high EMG signals in the right cervical rotation test, while the left SCMs showed low EMG signals in the left rotation. In addition, the high EMG signals in the right SCMs decreased when using the TBA or the CBA, but the EMG signals of the left SCMs showed low EMG values during the treatments. Furthermore, the EMG signals of the right SCMs rose again after artificial imbalance of the right TMJ by the CBA with one paper bar. This case report demonstrated the potential of EMG as an objective diagnostic method for FCST.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.330-336
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• 2014

Background For patients with full thickness skin defects, autologous Split-thickness skin grafts (STSG) are generally regarded as the mainstay of treatment. However, skin grafts have some limitations, including undesirable outcomes resulting from scars, poor elasticity, and limitations in joint movement due to contractures. In this study, we present outcomes of Matriderm grafts used for various skin tissue defects whether it improves on these drawbacks. Methods From January 2010 to March 2012, a retrospective review of patients who had undergone autologous STSG with Matriderm was performed. We assessed graft survival to evaluate the effectiveness of Matriderm. We also evaluated skin quality using a Cutometer, Corneometer, Tewameter, or Mexameter, approximately 12 months after surgery. Results A total of 31 patients underwent STSG with Matriderm during the study period. The success rate of skin grafting was 96.7%. The elasticity value of the portion on which Matriderm was applied was 0.765 (range, 0.635-0.800), the value of the trans-epidermal water loss (TEWL) was 10.0 (range, 8.15-11.00)$g/hr/m^2$, and the humidification value was 24.0 (range, 15.5-30.0). The levels of erythema and melanin were 352.0 arbitrary unit (AU) (range, 299.25-402.75 AU) and 211.0 AU (range, 158.25-297.00 AU), respectively. When comparing the values of elasticity and TEWL of the skin treated with Matriderm to the values of the surrounding skin, there was no statistically significant difference between the groups. Conclusions The results of this study demonstrate that a dermal substitute (Matriderm) with STSG was adopted stably and with minimal complications. Furthermore, comparing Matriderm grafted skin to normal skin using Cutometer, Matriderm proved valuable in restoring skin elasticity and the skin barrier.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.46-54
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• 2014

Direct shear tests have been initiated to understand the characteristics of joints which crucially affect the stability of rock mass. In this research, numerical approach in direct shear tests has been initiated using 3DEC on the basis of 3D distinct element method. Normal loads were altered in four different levels on artificial joint tests depending on the sawtooth angle and strengths on constant normal stress conditions, measuring the peak shear strength according to the direct shear tests under laboratory condition. Also results obtained from mechanical properties through laboratory test were used to perform numerical modeling, and shear strength obtained from the modeling was used to compare with laboratory direct shear test. As a result numerical analysis from distinct element method can simulate well on the shear behavior of rockmass.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.137-137
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• 2012

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위하여 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 라이너(Liner)와 헤드(Head) 부분이 직접적인 마모 운동을 수행하게 되므로, 이 부분의 소재 특성에 따라 인공관절의 수명이 결정 되게 된다. 현재 헤드 소재로서는 Co-Cr-Mo 합금이, 라이너 소재로서는 고분자 소재인 UHMWPE (Ultra High Molecular Weight Polyethylene)가 주로 사용되고 있다. 이러한 MOP (Metal-On-Polymer) 구조의 인공관절의 경우, 충격흡수의 장점이 있는 반면, 관절 운동시 발생하는 UHMWPE 의wear debris에 의해 골용해가 발생하게 되어 인공관절의 수명이 저하되는 문제점이 있으며, 금속 헤드의 마모로 인한 금속이온의 용출은 세포 독성의 문제를 야기하여 인공관절의 수명을 저하시키는 또 다른 원인이 되고 있다. 따라서 본 연구에서는 PIII&D (Plasma Immersion Ion Implantation & Deposition) 공정을 이용하여 금속 (Co-Cr-Mo 합금)소재 위에 세라믹 (niobium nitride) 박막을 증착하여 상대재인 UHMWPE의 마모를 줄이고자 하는 연구를 진행하였다. 금속 소재 위에 증착된 세라믹 박막은 상대재인 UHMWPE의 마모량을 줄여줄 뿐만 아니라 금속이온의 용출을 막아준다는 장점이 있으나, 장시간의 마모 운동에 의하여 발생하는 박막의 박리 현상은 인공관절의 수명을 급격히 저하시키는 또 다른 원인이 된다. 이러한 단점을 해결하기 위하여, 박막의 증착 초기에 이온주입과 증착을 동시에 수행하는 dynamic ion mixing공정을 수행하였다. Dynamic ion mixing 공정을 수행함에 따라 박막과 금속 사이의 접착력이 증가하게 되어, UHMWPE의 마모량이 2배 가까이 감소하는 것을 확인할 수 있었으며, 장시간의 마모시험에서도 우수한 결과를 얻을 수 있었다. 또한 UHMWPE의 마모량을 감소시키기 위하여 박막을 증착하기 전에 금속 소재에 질소 이온주입을 수행하는 pre-ion implantation 공정을 도입하였다. 질소 이온주입 결과 Co-Cr-Mo 합금 표면에 부분적으로 CrN, Cr2N의 세라믹 상이 형성 되는 것을 확인할 수 있었으며, 그에 따라 UHMWPE의 마모량이 2배 이상 감소 되는 것을 확인 할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.349-349
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• 2011

인공관절은 노인성 질환이나 자가 면역질환, 신체적인 외상 등으로 인하여 발생하는 관절의 손상 부위를 대체하기 위해 고안된 관절의 인공 대용물이다. 인공 관절 중 인공 고관절의 경우 관절 운동을 하는 라이너(Liner)와 헤드(Head) 부분이 인공관절의 수명을 결정하게 되는데, 헤드 부분에 메탈소재와 라이너 부분에 고분자 소재를 사용하는 MOP(metal on polymer) 구조의 인공관절은 충격흡수의 장점이 있는 반면 wear debris에 의한 골용해로 인하여 관절이 느슨해지는 문제점이 발생하여 재 시술의 주요 원인이 되고 있다. 현재 인공관절의 수명을 늘리기 위해 DLC, ZrO, TiN 등의 높은 경도 값을 갖는 박막을 금속헤드 위에 증착하여 상대재인 인공관절용 고분자 소재의 마모량을 줄이고자 하는 연구가 활발하게 진행되고 있다. 따라서 본 연구에서는 PIII&D(Plasma Immersion Ion Implantation & Deposition)공정을 이용하여 Co-Cr-Mo 합금 소재에 질소 이온을 주입 한 후 NbN 박막을 증착하여 상대재인 초고분자량 폴리에틸렌(UHMWPE)의 마모량을 줄이고자 하였다. NbN 박막의 특성을 평가하기 위해 XRD, XPS, AFM 등의 분석을 수행하였으며, 상대재인 초고분자량 폴리에틸렌의 마모량을 측정하기 위해 Pin-on-disk tribometer를 이용하여 마모 실험을 진행하였다. 마모 실험 결과, NbN 박막을 단순 증착한 경우, 현재 인공관절용 헤드(Head) 소재로 가장 널리 사용되고 있는 Co-Cr-Mo 합금에 비하여, 상대재인 초고분자량 폴리에틸렌의 마모량을 약 20% 감소시키는 것을 알 수 있었다. 또한, Co-Cr-Mo 합금 소재에 질소 이온주입을 하여 표면을 개질한 후, NbN 박막을 증착한 경우, 마모량이 최대 50%까지 감소하는 것을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.709-730
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• 2017

To address the challenge of unprecedented growth in mobile data traffic, ultra-dense network deployment is a cost efficient solution to offload the traffic over some small cells. The overlapped coverage areas of small cells create more than one candidate access points for one mobile user. Signal strength based user association in IEEE 802.11 results in a significantly unbalanced load distribution among access points. However, the effective bandwidth demand of each user actually differs vastly due to their different preferences for mobile applications. In this paper, we formulate a set of non-linear integer programming models for joint user association control and user demand guarantee problem. In this model, we are trying to maximize the system capacity and guarantee the effective bandwidth demand for each user by soft-association control with a software defined network controller. With the fact of NP-hard complexity of non-linear integer programming solver, we propose a Kernighan Lin Algorithm based graph-partitioning method for a large-scale network. Finally, we evaluated the performance of the proposed algorithm for the edge users with heterogeneous bandwidth demands and mobility scenarios. Simulation results show that the proposed adaptive soft-association control can achieve a better performance than the other two and improves the individual quality of user experience with a little price on system throughput.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.4
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• pp.331-338
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• 2017

In this study, a portable x-ray generator was manufactured and a real-time image acquisition system was constructed using the image intensifier from the generated generator. We have developed a real - time position error verification system that can verify whether the artificial joint position is different from the initial image from the acquired image. The template image of the region of interest is extracted from the reference image using the pattern matching technique and compared with the image to be compared. As a result, It is shown that real - time position error verification is achieved by displaying the difference angle. This system is portable type, has a self-shielding facility, and the output of the irradiation device can be manufactured in a small size of 1kw and can be used as a portable type. In case of emergency patients in the non-destructive field for industrial use, It has proved effective for use in small areas such as feet.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.455-464
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• 2004

Total hip arthroplasty(THA) considerably depends on high-experienced doctors because of high difficulty of the operation. Selection of acetabular cup's and femoral implant's position is closely related with success or failure of THA. Nevertheless the selection has usually depended on doctor's eye measurement, which makes the position accuracy of artificial joint lower after THA, often resulting in revision of THA. The present study determined a method to select accurately the position of acetabular cup and femoral implant through surgical simulation with 3D characteristic geometrical information of patient's pelvis and femur. We examined the change of femoral anteversion angle and neck-shaft angle accompanied by the change of acetabular cup's position and the insertion position of femoral implant. As result of analyzing geometrical information through different surgical simulations, we found that it was possible to select the accurate position of acetabular cup and femoral implant. It is expected to help doctors get experienced in THA operation through repetitive surgical simulations using the method suggested in the study.