• Communications for Statistical Applications and Methods
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• 제10권3호
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• pp.795-804
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• 2003

In this article, a tomography for the estimation of the origin-destination(OD) traffic intensities in dynamic routing network is considered. Vardi(1996)'s approach based on fixed route is not directly applicable to dynamic routing protocols, which arises from the fact that we cannot access the route at every observation time. While it uses link-wise traffics as the observations, the proposed method considers the triple of ingress/outgress/relayed traffics data at each node so that we can transform the problem into a routing-independent tomography. An EM algorithm for implementation and some simulated experiments are provided.

• International journal of advanced smart convergence
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• 제8권4호
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• pp.154-160
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• 2019

In this paper, we propose the miniaturization size of wearable Range of Motion(ROM) and a system that can be connected with smart devices in real-time to measure the joint movement range dynamically. Currently, the ROM of the joint is directly measured by a person using a goniometer. Conventional methods are different depending on the measurement method and location of the measurement person, which makes it difficult to measure consistently and may cause errors. Also, it is impossible to measure the ROM of joints in real-life situations. Therefore, the wearable sensor is attached to the joint to be measured to develop a miniaturize size ROM device that can measure the range of motion of the joint in real-time. The sensor measured the resistance value changed according to the movement of the joint using a load cell. Also, the sensed analog values were converted to digital values using an Analog to Digital Converter(ADC). The converted amount can be transmitted wireless to the smart device through the wearable sensor node. As a result, the developed device can be measured more consistently than the measurement using the goniometer, communication with IoT-based smart devices, and wearable enables dynamic observation. The developed wearable sensor node will be able to monitor the dynamic state of rehabilitation patients in real-time and improve the rapid change of treatment method and customized treatment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.2936-2951
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• 2016

An emerging satellite technology, Operationally Responsive Space (ORS) is expected to provide a fast and flexible solution for emergency response, such as target tracking, dense earth observation, communicate relaying and so on. To realize large distance transmission, we propose the use of available relay satellites as relay nodes. Accordingly, we apply software defined network (SDN) technology to ORS networks. We additionally propose a satellite network architecture refered to as the SDN-based ORS-Satellite (Sat) networking scheme (SDOS). To overcome the issures of node failures and dynamic topology changes of satellite networks, we combine centralized and distributed routing mechanisms and propose a fast recovery routing algorithm (FRA) for SDOS. In this routing method, we use centralized routing as the base mode.The distributed opportunistic routing starts when node failures or congestion occur. The performance of the proposed routing method was validated through extensive computer simulations.The results demonstrate that the method is effective in terms of resoving low end-to-end delay, jitter and packet drops.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2732-2753
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• 2019

With the application of wireless sensor networks in the fields of ecological observation, defense military, architecture and urban management etc., the security problem is becoming more and more serious. Characteristics and constraint conditions of wireless sensor networks such as computing power, storage space and battery have brought huge challenges to protection research. Inspired by the danger theory in biological immune system, this paper proposes an intrusion detection model for wireless sensor networks. The model abstracts expressions of antigens and antibodies in wireless sensor networks, defines meanings and functions of danger signals and danger areas, and expounds the process of intrusion detection based on the danger theory. The model realizes the distributed deployment, and there is no need to arrange an instance at each sensor node. In addition, sensor nodes trigger danger signals according to their own environmental information, and do not need to communicate with other nodes, which saves resources. When danger is perceived, the model acquires the global knowledge through node cooperation, and can perform more accurate real-time intrusion detection. In this paper, the performance of the model is analyzed including complexity and efficiency, and experimental results show that the model has good detection performance and reduces energy consumption.

• 한국콘텐츠학회논문지
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• 제6권7호
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• pp.69-78
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• 2006

본 논문에서는 네트워크 물리층이 광소자들로 구성된 액티브 광 링네트워크 시스템에서의 전송 능력과 그에 따른 효율성에 관하여 기술한다. 실험을 위한 시뮬레이션은 광 전송 시스템에서 광 전송 품질을 측정 할 수 있는 트랜스미션메이커 WDM(Transmissionmaker WDM)이 사용되었다. 광액티브 네트워크는 메인링과 서브링에 의한 두 개의 링으로 구성되었다. 서브링의 노드 개수와 각 노드들 간의 간격에 따른 비트 에러율 (Bit Error Rate)의 특성을 측정한다. 이러한 물리층에서의 성능 분석은 액티브 광 링네트워크의 성능 최적화를 위한 설계의 기준이 된다. 따라서 궁극적으로는 실제 가입자망에서 각 노드의 물리적 거리, 트래픽 요구량, 가입자 수를 반영한 효율적인 광전송 시스템을 구성할 수 있다.

• Archives of Plastic Surgery
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• 제46권5호
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• pp.441-448
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• 2019

Background Merkel cell carcinoma (MCC) is a rare neuroendocrine malignancy affecting the skin, for which timely diagnosis and aggressive treatment are essential. MCC has most often been reported in Caucasians, and case reports in Asians are rare. This study presents our experiences with the surgical treatment and radiotherapy of MCC in Asian patients. Methods We retrospectively reviewed the records of seven MCC patients between 2000 and 2018 from a single institution, and analyzed patient characteristics, tumor characteristics, surgical treatment, sentinel lymph node evaluation, reconstruction, adjuvant radiation therapy, and prognosis. Results Eight MCC lesions occurred in seven patients, most commonly in the head and neck region. All patients underwent surgical excision with reconstruction. The final surgical margin was 1.0 cm in most cases, and reconstruction was most commonly performed with a splitthickness skin graft. Five patients received adjuvant radiotherapy, and two patients received sentinel lymph node biopsy. During the follow-up period, three patients remained well, two died from other causes, one experienced recurrence, and one was lost to follow-up. Conclusions We treated seven Asian MCC patients and our series confirmed that MCC is a very dangerous cancer in Asians as well. Based on our experiences, thorough surgical excision of MCC with histopathological clearance should be considered, with sentinel lymph node evaluation if necessary, followed by appropriate reconstruction and careful postoperative observation. Adjuvant radiation therapy is also recommended for all Asian MCC patients. The results of this case series may provide guidance for the treatment of Asian MCC patients in the future.

• 대한예방한의학회지
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• 제26권3호
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• pp.29-40
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• 2022

Objective : This study assessed the effect of a combination of Korean medicine on a thyroid papillary cancer patient who was diagnosed with local lymph node metastasis after thyroidectomy and lymph node dissection but did not want surgery. Methods : Gami-Palmultang administration and moxibustion(large Bmoxa cautery) were performed for six years. Treatment outcomes were evaluated with Brief Fatigue Inventory (BFI), Numerical Rating Scale (NRS), Insomnia Severity Index (ISI), Functional Assessment of Cancer Therapy-General (FACT-G), blood test/ CT imaging results, and patient's statements. Results : After the treatment, all symptoms have been alleviated, the quality of life has increased, and it has been maintained without further metastasis of tumors for six years. Conclusion : Korean medicine treatment along with active observation can be an alternative to patients who do not want surgical treatment after recurrence of local lymph nodes in thyroid papillary cancer, and can have positive results in improving the quality of life.

• Tuberculosis and Respiratory Diseases
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• 제56권1호
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• pp.18-28
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• 2004

연구 배경 : 미세침 흡인 세포검사법은 말초 림프절 비대의 원인규명에 매우 우수한 선별검사로 알려져 있으나 각 원인질환이나 림프절의 이학적 소견에 따른 유용성이나 검사한계에 대한 연구는 아직 미진하다. 방 법 : 경부 림프절 비대를 주소로 내원한 16세 이상 성인환자들 중 진단을 위해 미세침 흡인 세포검사법을 시행 받고 외과적 조직 생검, 미생물 검사, 임상적추적관찰 등을 통해 최종 진단이 가능했던 342명을 대상으로 검사의 예민도와 유용성, 문제점이 각 원인 질환이나 림프절의 이학적 소견에 따라서 어떠한지를 후향적으로 알아보았다. 결 과 : 342명의 림프절 비대 환자 중 양성 병변은 176예인 51.5 %, 결핵성 림프절염은 88예로 25.7 %, 악성 종양의 전이는 66예로 19.3 %, 그리고 림프종은 12예로 3.5 %였다. 결핵성 림프절염, 악성 종양의 전이, 림프종 등으로 최종 진단된 환자군들은 양성 병변에 비해서 높은 연령을 보였고 남성이 많았으며 빗장위 림프절을 침범한 경우가 많았다. 림프절의 이학적 특징에서도 림프절의 평균 크기가 특이 질환이 있는 군에서 양성 병변인 군에 비해서 유의하게 컸으며 20 mm 이상의 크기를 가진 환자들의 수도 유의하게 많았다. 악성 종양의 전이인 경우에는 고정화됐거나 굳은 경도를 가진 경우가 유의하게 많았다. 미세침 흡인 세포검사법은 전체적으로 88 %의 진단 예민도를 보였으며 악성 종양의 전이인 경우가 90.1 % 로 가장 높았고 림프종인 경우에 58.3% 로 가장 낮았다 양성 병변인 경우는 88.6 %, 결핵성 림프절염인 경우는 77.3 %의 예민도를 보였다. 미세침 흡인 세포검사법의 진단 예민도는 질환의 종류나 비대 기간, 림프절의 크기 등과 관련이 없었고 다만 빗장위 림프절인 경우에는 80.0 % 로 다른경부 림프절의 91.3 % 에 비해서 유의하게 낮은 예 민도를 보였다.결 론 : 미세침 흡인 세포검사법은 림프절 비대의 원인 감별에 우수한 선별진단법으로 판단되나 림프종이 의심되거나 빗장위 림프절의 경우에는 낮은 진단율을 보이므로 주의해야 한다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.560-564
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• 2007

한국기초과학지원연구원(KBSI, Korea Basic Science Institute)에서는 국내 유일의 초고전압투과전자현미경(HVEM, High Voltage Electron Microscopy)을 비롯하여 3 대의 일반 전자현미경을 보유하고 있다. 전자현미경을 통하여 관찰된 이미지는 각 단계별로 tilting 되어 저장된 이미지로서 관찰자에게 보다 나은 관찰 환경의 구성을 위해 3D로의 reconstruction은 필수 과정이라고 할 수 있겠다. 이 과정 중 카메라 중심에서 벋어난 부분의 왜곡을 warping 기법을 통하여 최대한 감소시킨다. 이런 이미지 전처리 과정과 이를 바탕으로 3D로의 reconstruction과정은 고성능 컴퓨터의 수반을 기본으로 하는데 이 과정을 다수의 grid node PC들이 빠른 시간에 분담하여 처리하게 된다. Grid node PC들의 역할은 소유자가 서로 다른 다양한 컴퓨팅 자원의 효과적인 공유를 목적으로 하며, 시스템의 구축에 필요한 역할 스케줄링, 자원 관리, 보안, 성능 측정 및 상태 모니터링 등의 문제를 해결하기 위한 사용되고 있다. 일반 개인이 사용하기 힘들었던 고성능 PC의 역할을 Grid node PC들이 수행하고 이 기반위에 워핑 기법을 통한 이미지 전처리는 보다 실제 관찰 대상에 가까운 형태로의 재구성이 가능할 수 있는 바탕이 된다. 워핑 전처리를 통한 Grid node PC기반의 전자현미경 볼륨 랜더링 시스템의 구축은 관찰자에게 보다 편리하며 빠른 실험 환경을 제공하여 줄 수 있고, 이해하기 쉽고 실제 모습에 가까운 형태의 실험 결과물을 접할 수 있게 된다.

• Journal of Mechanical Science and Technology
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• 제14권9호
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• pp.978-984
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• 2000

The aim of this study is to investigate the ductile fracture behaviour under Mode I loading using SA533B pressure vessel steel. Experiments consist of the Round Notch Bar Test (RNB), Single Edge Crack Bending Test (SECB), and V-Notch Bar Test (VNB). Results from the RNB test were used to tune the damage modelling constant. The other tests were performed to acquire the J-resistance curves and to confirm the damage constants. Microstructural observation includes the measurement of crack profile to obtain the roughness parameter. Finally, simulation using Rousellier Ductile Damage Theory (RDDT) was carried out with 4-node quadrilateral element ($L_c=0.25\;mm$). For the crack advance, the failed element removal technique was adopted with a ${\beta}$ criterion. In conclusion, the predicted simulation using RDDT showed a good agreement with the experimental results. A trial using a roughness parameter was made for a new evaluation of J-resistance curve, which is more conservative than the conventional one.