• 한국정보통신학회논문지
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• 제26권10호
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• pp.1537-1544
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• 2022

application specific integrated circuit (ASIC) 및 system on chip (SoC) 설계 시 디지털 회로는 클럭에 동기화되어 작동한다. 칩 설계 시, place & route (P&R)에서 설계 조건과 타이밍 조건, 클럭의 동기화 여부 등을 고려한다. P&R에서 클럭 경로에 대한 delay를 줄이기 위해, clock tree synthesis (CTS) 기법을 이용한다. 본 논문에서는 사전 클럭트리 합성 가능 여부 판단을 위한 shallow-CTS 알고리즘을 소개한다. 오픈 소스 Parser-Verilog를 사용하여 register transfer level (RTL) 합성가능한 Verilog를 파싱하여, Pre-CTS와 Post-CTS 단계를 진행하고, 가장 긴 clock path와 버퍼 삽입 전후의 표준편차를 비교하여 CTS의 정확도에 대해 분석한다. 본 논문에서 시간 투입이 많이 되는 licensed EDA tool을 사용하여 CTS 결과를 확인하지 않고, RTL 수준에서 사전 클럭 트리 합성 검증 방법을 제공하여 비용 및 시간문제를 감소할 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.391-393
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• 2004

For performance and stability of a synchronized system, we need an efficient Clock Tree Synthesis(CTS) methodology to design clock distribution networks. In a system-on-a-chip(SOC) design environment, CTS effectively distributes clock signals from clock sources to synchronized points on layout design. In this paper, we suggest the pre-layout analysis of the clock network including gated clock, multiple clock, and test mode CTS optimization. This analysis can help to avoid design failure with potential CTS problems from logic designers and supply layout constraints so as to get an optimal clock distribution network. Our new design flow including pre-layout CTS analysis and structural violation checking also contributes to reduce design time significantly.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.137-142
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• 2003

In this study, the propagation behavior of fatigue crack effected hole defects was investigated under mixed-mode I+II loading. To create mixed-mode stress field at crack tip, the compact tension shear (CTS) specimen and loading device were used in this tests. The propagation experiments of fatigue crack were performed by changing of the loading application angle(${\phi}$) and the distance(L) estimated from pre-crack tip to hole center located side by side by side with a pre-crack. As L changes, the variation for propagation aspect of fatigue crack, fatigue life and crack propagation rate were examined under mixed-mode loading. Under mixed-mode loading, the propagation rate of fatigue crack increased while the propagation direction changed dramatically because of the interference of hole defects.

• 대한정형도수물리치료학회지
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• 제16권2호
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• pp.48-52
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• 2010

Object: The aim of this study is to descrive the effect of neurodynamic technique and self management exercise for carpal tunnel syndrome patients(CTS) Method: 13 patients with CTS participated in this study. They were from 18 to 70 years old and mean age was 25.3. In the evalutaion, gripping with grip dynamometer, strength of gripping with precision pinchmeter, pain level with visual analogue scale. All measurement of each subject were measure at pre- treatment and post treatment(after 1week) and post treattment(after 2 weeks) stage. The physical therapy program consisted of neurodynamic technique and self management exercise. SPSS 12.0 program was used to compile result. Result: The grip, pinch, VAS-P were significantly difference between pre-treatment and post treatment(after 2weeks)(p<.05) Conclusion: This study suggest that 3weeks neurodynamic technique and self management exercise improved grip and pinch strength and decrease pain score.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.302-307
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• 2004

This paper reviewed characteristics of fatigue crack behavior observed by changing various shapes of initial crack and magnitudes of loading in compact tension shear(CTS) specimen subjected to shear loading. In the high-loading condition, fatigue crack under shear loading propagated branching from the pre-crack tip. Meanwhile, the secondary fatigue crack in the low-loading condition which was created in the notch root due to friction on the pre-crack face grew to a main crack. Influenced by the mode II loading condition, fatigue crack propagation retardation appeared in the initial propagation region due to the reduction of crack driving force and friction on crack face. In both cases, however, fatigue cracks grew in tensile mode type. Propagation path of fatigue crack under the shear loading was 70 degree angle from the initial crack regardless of its shape and load magnitude.

• 한국전문물리치료학회지
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• 제16권1호
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• pp.61-69
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• 2009

The objective of this study was to investigate the relationship between addiction to online games and carpal tunnel syndrome (CTS) in college students. A total of 377 (205 male and 172 female) college students completed an online game addiction scale, a Symptom Severity Scale (SSS), and a Function Status Scale (FSS) for CTS. It was found that five (1.3%) students were diagnosed with an online game addiction, 74 (19.6%) students were diagnosed with a pre-addiction to online games, and 298 (79.0%) students were diagnosed as being average users. The pre-addiction group had significantly higher scores on the SSS than did the average user group (p<.05). The average user group scored significantly lower than did the online game addiction group (p<.05). Symptoms of wrist pain and hand numbness in the daytime were common in the addiction group. There were statistically significant but poor positive relationships between the online game addiction scale and the SSS (r=.312, p<.01), and between the online game addiction scale and the FSS (r=.149, p<.01). The information about online game addiction and CTS identified in this study could contribute to the prevention of online game addiction and CTS in college students.

• 한국통신학회논문지
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• 제35권11B호
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• pp.1685-1695
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• 2010

본 논문에서는 IEEE 802.11 기반의 군 전술 네트워크에서 신뢰성을 보장하면서 망 생존성 향상을 위해 저피탐 성능을 향상시킬 수 있는 멀티캐스팅 MAC 프로토콜을 제안한다. RTS-CTS 기법을 사용하는 IEEE 802.11 기반의 멀티캐스팅 MAC에서는 신뢰성을 보장하기 위해 송신측이 보낸 RTS와 DATA의 수신 확인을 위한 모든든 수신단말의 CTS와 ACK가 보내져야 한다. 제안하는 프로토콜에서는 연속적인 CTS와 ACK 대신 MC-DS/CDMA 기술을 이용하여 병렬적인 CTS와 ACK를 전송함으로써 전송 오버헤드를 낮출 수 있다. 또한 이 기법을 적이 아군의 신호를 탐지하려고 시도하는 전술환경에 적용시 코드를 통해 전송 파워를 제어함으로써 확산 이득을 통해 송신 단말은 다수의 수신 단말로부터 전송된 신호를 받을 수 있지만, 적 검파기에는 탐지 확률이 낮아짐으로 인해 저피탐 성능 역시 얻을 수 있는 장점이 있다. 제안하는 기법은 IEEE 802.11a 기반 시뮬레이션을 통해 기존에 연속적으로 CTS와 ACK를 전송하는 신뢰성 있는 멀티캐스팅 MAC 프로토콜보다 시스템 처리량, 메시지 전송 지연시간 저피탐 성능에서 신뢰성을 유지하면서 효율성과 생존성을 동시에 높일 수 있음을 보여준다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.487-490
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• 2004

In this paper, we investigated the characteristics of initiation and propagation behavior for fatigue crack observed by changing various shapes of initial crack and magnitudes of loading in modified compact tension shear(CTS) specimen subjected to shear loading. In the low-loading condition, the secondary fatigue crack was created in the notch root due to friction on the pre-crack face grew to a main crack. In the high-loading condition, fatigue crack under shear loading propagated branching from the pre-crack tip. Influenced by the shear loading condition, fatigue crack propagation retardation appeared in the initial propagation region due to the reduction of crack driving force and friction on crack face. In both cases, however, fatigue cracks grew in tensile mode type. The propagation path of fatigue crack under the Mode II loading was 70 degree angle from the initial crack regardless of its shape and load magnitude.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.4143-4147
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• 2016

Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males; mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic findings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV); 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The specificity, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no significant difference between SUVmax of TP lesions and FP lesions (p>0.95) but significantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this finding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake reflecting pre-malignant and malignant lesions, and the need for appropriate follow up.

• 한국학교수학회논문집
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• 제20권3호
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• pp.239-254
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• 2017

본 연구는 고등학교 학생의 수학에 대한 가치 인식 및 흥미를 증진시키는 방안을 모색하는데 일환을 두고 수행되었다. 이와 같은 교육적 목적을 달성하기 위해서는 단편적 교과 지식의 학습 보다는 융합적인 접근을 통해 학생들이 자신의 지식을 적용할 기회가 제공되어야 한다는 주장에 따라 사회와 수학을 융합한 프로그램을 개발하고 그 적용 효과를 파악하고자 하였다. 효과성 검증을 위한 데이터 수집은 일반계 고등학교 학생들을 대상으로 사회 수학 프로그램 적용에 따른 사전 사후 설문을 통해서 이루어졌다. 사회 수학 프로그램은 실생활에서 나타나는 사회적 현상을 수학적 관점에서 문제를 해결하고자 하는 시도로서, 적용 결과 학생들은 수학 학습 및 사회 학습에 대한 태도, 수학 학습 및 사회 학습 가치 인식에 효과적인 것을 확인할 수 있었다.