• 한국콘텐츠학회논문지
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• 제13권2호
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• pp.52-61
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• 2013

무선 센서 네트워크에서 재난, 환경 모니터링 등에 대한 응용으로써 센서 노드의 지리학적 위치 측정은 매우 중요하다. 이를 위해 무선 센서 네트워크 분야는 Range-free 위치 측정 기법에 대한 연구가 활발하게 진행 중이며, 비 균일 네트워크 환경에서 위치 정확도를 향상하기 위한 중심 극한 정리와 정규 분포에 근거한 위치 측정 기법인 밀집 확률 기법이 제안되었다. 밀집 확률 기법의 경우 노드 통신을 통해 거리를 추정 후 최종 위치를 측정하지만 거리 추정 시 주위 인근 모든 노드가 동일한 1-홉 추정 거리를 갖는 문제점이 발생한다. 따라서 본 논문에서는 이러한 오차를 최소화하기 위해 각 노드마다 거리 추정 후 센싱 반경을 조절하여 2차 지역 거리 평가를 통해 센서의 위치를 측정하는 기법을 제안한다. 성능평가 결과, 제안하는 기법은 밀집 확률 기법에 비해 9% 더 높은 정확도를 보였다. 또한 대표적인 Range-free 위치 측정 기법인 DV-HOP에 비해 48% 더 우수한 위치 정확도를 보였다.

• Structural Engineering and Mechanics
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• 제90권3호
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• pp.253-261
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• 2024

This research explores a new finite element model for the free vibration analysis of bi-directional functionally graded (BDFG) beams. The model is based on an efficient higher-order shear deformation beam theory that incorporates a trigonometric warping function for both transverse shear deformation and stress to guarantee traction-free boundary conditions without the necessity of shear correction factors. The proposed two-node beam element has three degrees of freedom per node, and the inter-element continuity is retained using both C1 and C0 continuities for kinematics variables. In addition, the mechanical properties of the (BDFG) beam vary gradually and smoothly in both the in-plane and out-of-plane beam's directions according to an exponential power-law distribution. The highly elevated performance of the developed model is shown by comparing it to conceptual frameworks and solution procedures. Detailed numerical investigations are also conducted to examine the impact of boundary conditions, the bi-directional gradient indices, and the slenderness ratio on the free vibration response of BDFG beams. The suggested finite element beam model is an excellent potential tool for the design and the mechanical behavior estimation of BDFG structures.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.753-757
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• 2013

Objective: To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis. Methods and Patients: We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (${\leq}0.20$), intermediate-risk (> 0.20 but ${\leq}0.65$), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS. Results: A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P=0.002 in Group A, P<0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A. Conclusions: LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.41-52
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• 2022

This paper analyzes the advantages and opportunities of regional development prospects of the China (Anhui) Pilot Free Trade Zone. In addition, it provides suggestions for the future development of the Anhui Pilot Free Trade Zone. The establishment of the Anhui Pilot Free Trade Zone is a major platform for Anhui Province, China, to serve the nation's opening-up strategy to the world and an opportunity for the Anhui region to enhance the level of an open economy. The development plan points out that the Anhui Pilot Free Trade Zone 1) takes institutional innovation as the core, 2) complies with the requirements of the innovation-driven development and promotion of the Yangtze River Delta regional integration development strategy, and 3) plays a vital node role in promoting the construction of the Belt and Road Initiative, and 4) accelerates the construction of scientific and technological innovation sources, advanced manufacturing and strategic emerging industries. The findings of this study highlight three critical achievements as follows: 1) optimization and improvement of the business environment have progressed, 2) the conversion rate of scientific and technological innovation achievements has increased, and 3) advanced high-tech manufacturing and strategic emerging industries are clustered and developed.

• Radiation Oncology Journal
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• 제37권2호
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• pp.91-100
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• 2019

Purpose: Internal mammary lymph node (IMN) involvement is associated with poor prognosis in breast cancer. This study investigated the treatment outcomes of initial clinically IMN-positive breast cancer patients who received adjuvant radiotherapy (RT), including IMN irradiation, following primary breast surgery. Materials and Methods: We retrospectively reviewed data of 95 breast cancer patients with clinically detected IMNs at diagnosis treated with surgery and RT between June 2009 and December 2015. Patients received adjuvant RT to the whole breast/chest wall and regional lymph node (axillary, internal mammary, and supraclavicular) areas. Twelve patients received an additional boost to the IMN area. Results: The median follow-up was 43.2 months (range, 4.5 to 100.5 months). Among 77 patients who received neoadjuvant chemotherapy, 52 (67.5%) showed IMN normalization and 19 (24.6%) showed a partial response to IMN. There were 3 and 24 cases of IMN failure and any recurrence, respectively. The 5-year IMN failure-free survival, disease-free survival (DFS), and overall survival (OS) were 96%, 70%, and 84%, respectively. IMN failure-free survival was significantly affected by resection margin status (97.7% if negative, 87.5% for close or positive margins; p = 0.009). All three patients with IMN failure had initial IMN size ≥1 cm and did not receive IMN boost irradiation. The median age of the three patients was 31 years, and all had hormone receptor-negative tumors. Conclusion: RT provides excellent IMN control without the support of IMN surgery. Intensity-modulated radiotherapy, including IMN boost for breast cancer patients, is a safe and effective technique for regional lymph node irradiation.

• 인터넷정보학회논문지
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• 제3권1호
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• pp.41-49
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• 2002

MPLS망에서 루프 경로가 형성되는 것을 방지하기 위한 방안으로 Ohba는 칼라 스레드 알고리즘을 제안하였다. LSP를 설정할 때 중간 노드가 칼라와 홉 카운트, TTL 값으로 표현된 스레드 정보를 LDP메시지를 이용하여 다운스트림 노드에게 전달한다. 그 다음 같은 칼라의 스레드가 다시 접수되면, 루프 경로가 형성되었음을 감지하고 다른 경로의 탐색을 시도한다. 메시지가 egress 노드에 도착하면 ingress 노드까지 업스트림으로 확인 메시지를 역 전송하여, 루프가 없는 경로를 설정한다. 이를 위해 Ohba가 스레드의 상태를Null, Colored, Transparent의 세 가지로 정의한 것을Extending, Merging, Stalling, Null, Transparent의 5가지로 확장하여 정의하고, 이에 따라 관련 FSM과 TCB를 재정의 하여 스레드 상태의 모호성으로 인한 잘못된 동작과 오버로드의 발생을 개선코자 하였다. 그리고, Stalling 상태에서 스레드 생성을 회피함으로써, 성능의 향상을 유도하였다.

• Radiation Oncology Journal
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• 제35권4호
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• pp.349-358
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• 2017

Purpose: This study aimed to evaluate whether prophylactic extended-field pelvic radiotherapy (EF-PRT) yields better results than standard whole pelvic radiotherapy (WPRT) in patients with pelvic lymph node-positive cervical cancer treated with concurrent chemoradiotherapy (CCRT). Materials and Methods: A total of 126 cases of stage IB-IVA cervical cancer that had pelvic lymph node involvement in magnetic resonance imaging and were treated with CCRT between 2000 and 2016 were reviewed. None of the patients had para-aortic lymph node (PALN) metastases. The patients were classified to two groups, namely, those treated with EF-PRT, including prophylactic para-aortic radiotherapy, and those treated only with WPRT. The median dose to the PALN area in patients treated with EF-PRT was 45 Gy. All patients received concurrent cisplatin-based chemotherapy. Results: Overall, 52 and 74 patients underwent EF-PRT and WPRT, respectively. Patient characteristics and irradiated dose were not significantly different, except the dose to the para-aortic area, between the two groups. The median follow-up period was 75.5 months (range, 5 to 195 months). The 10-year cumulative recurrence rate of PALN for EF-PRT vs. WPRT was 6.9% and 10.1% (p = 0.421), respectively. The 10-year disease-free survival and overall survival for EF-PRT vs. WPRT were 69.7% vs. 66.1% (p = 0.748) and 71.7% vs. 72.3% (p = 0.845), respectively. Acute gastrointestinal complications were significantly higher in EF-PRT (n = 21; 40.4%) than WPRT (n = 26; 35.1%) (p = 0.046). Late toxicities were not significantly different in both groups. Conclusion: In this study, prophylactic radiotherapy for PALN does not have an additional benefit in patients with pelvic lymph node-positive cervical cancer treated with CCRT.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.504-527
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• 2015

Underwater wireless sensor networks (UWSNs) are similar to the terrestrial sensor networks. Nevertheless, there are different characteristics among them such as low battery power, limited bandwidth and high variable propagation delay. One of the common major problems in UWSNs is determining an efficient and reliable routing between the source node and the destination node. Therefore, researchers tend to design efficient protocols with consideration of the different characteristics of underwater communication. Furthermore, many routing protocols have been proposed and these protocols may be classified as location-based and location-free routing protocols. Pressure-based routing protocols are a subcategory of the location-free routing protocols. This paper focuses on reviewing the pressure-based routing protocols that may further be classified into non-void avoidance protocols and void avoidance protocols. Moreover, non-void avoidance protocols have been classified into single factor based and multi factor based routing protocols. Finally, this paper provides a comparison between these protocols based on their features, performance and simulation parameters and the paper concludes with some future works on which further study can be conducted.

• 한국공간구조학회논문집
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• 제14권3호
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• pp.47-56
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• 2014

This paper investigates the characteristics of unstable behaviour and critical buckling load by joint rigidity of framed large spatial structures which are sensitive to initial conditions. To distinguish the stable from the unstable, a singular point on equilibrium path and a critical buckling level are computed by the eigenvalues and determinants of the tangential stiffness matrix. For the case study, a two-free node example and a folded plate typed long span example with 325 nodes are adopted, and these adopted examples' nonlinear analysis and unstable characteristics are analyzed. The numerical results in the case of the two-free node example indicate that as the influence of snap-through is bigger; that of bifurcation buckling is lower than that of the joint rigidity as the influence of snap-through is lower. Besides, when the rigidity decreases, the critical buckling load ratio increases. These results are similar to those of the folded-typed long span example. When the buckling load ratio is 0.6 or less, the rigidity greatly increases.

• 한국광학회지
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• 제30권6호
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• pp.230-236
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• 2019

저렴한 retro-반사지와 미소 전자 기계 시스템(micro electro-mechanical system, MEMS) 거울을 이용한 실내용 무선 광 통신용 위치 탐색 및 자동 링크 정렬 방법을 제안하고 실험하였다. 직접적인 가시선(line of sight, LOS) 확보를 위하여 retro-반사지에서 돌아온 빛으로부터 수신단 위치를 파악하고 MEMS 거울을 통한 빔 조종으로 통신 링크를 자동 정렬하였다. 자동 정렬된 광 링크를 통하여 7 m 전송 거리에서 2.5 Gb/s NRZ 신호를 전송하여 비트 에러율 10^-12에서 수신 감도 -31.87 dBm의 성능을 가졌다.