• 제목/요약/키워드: Independent joint control

검색결과 116건 처리시간 0.023초

Ag-Ti계 합금을 사용한 SiC/SiC 및 SiC/연강 브레이징에 대한 연구 (A Study on SiC/SiC and SiC/Mild steel brazing by the Ag-Ti based alloys)

  • 이형근;이재영
    • Journal of Welding and Joining
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    • 제14권4호
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    • pp.99-108
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    • 1996
  • The microstructure and bond strength are examined on the SiC/SiC and SiC/mild steel joints brazed by the Ag-Ti based alloys with different Ti contents. In the SiC/SiC brazed joints, the thickness of the reaction layers at the bond interface and the Ti particles in the brazing alloy matrices increase with Ti contents. When Ti is added up to 9 at% in the brazing alloy. $Ti_3SiC_2$ phase in addition to TiC and $Ti_5Si_3$ phase is newly created at the bond interface and TiAg phase is produced from peritectic reaction in the brazing alloy matrix. In the SiC/mild steel joints brazed with different Ti contents, the microstructure at the bond interface and in the brazing alloy matrix near SiC varies similarly to the case of SiC/SiC brazed joints. But, in the brazing alloy matrix near the mild steel, Fe-Ti intermetallic compounds are produced and increased with Ti contents. The bond strengths of the SiC/SiC and SiC/mild steel brazed joints are independent on Ti contents in the brazing alloy. There are no large differences of the bond strength between SiC/SiC and SiC/mild steel brazed joints. In the SiC/mild steel brazed joints, Fe dissolved from the mild steel does not affect on the bond strength of the joints. Thermal contraction of the mild steel has nearly no effects on the bond strength due to the wide brazing gap of specimens used in the four-point bend test. The brazed joints has the average bond strength of about 200 MPa independently on Ti contents, Fe dissolution and joint type. Fracture in four-point bend test initiates at the interface between SiC and TiC reaction layer and propagates through SiC bulk. The adhesive strength between SiC and TiC reaction layer seems to mainly control the bond strength of the brazed joints.

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험로 주행을 위한 다중모듈 로봇의 설계 (Development of Multi-Link Mobile Robot for Rough Road Driving)

  • 백유광;한경호;신인철
    • 전기전자학회논문지
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    • 제14권2호
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    • pp.58-63
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    • 2010
  • 본 논문에서, 평탄한 경로 뿐 아니라 바위 등의 험로환경에서도 로봇이 주행하도록 다족류 절지동물과 유사한 구조를 갖는 다중 모듈형 로봇의 설계 및 구현을 다룬다. 각 모듈은 독립 전원과 제어장치, 구동부 및 근거리 Zigbee 무선통신을 포함하고 있으며 절지동물의 한마디를 구현하였다. 주행방향 및 경로 조건에 따라 각 모듈은 무선통신에 의하여 동일한 주행방향을 가지며 모듈의 구동부를 가동 또는 차단할 수 있도록 설계하였다. 주행시 경로의 조건에 따라 각 모듈의 속도와 토크를 계산하며 험한 경로의 경사도에 따라 구동 되는 모듈 수를 가변적으로 조정하여 험로 및 평탄도로 등의 다양한 경로환경에 효율적으로 주행하도록 하였다. 험로 모델을 이용한 실험을 통하여 모듈을 가변적으로 구동할 수 있는 로봇을 구현하였다.

Multiplicity of Advanced T Category-Tumors Is a Risk Factor for Survival in Patients with Colorectal Carcinoma

  • Park, Hye Eun;Yoo, Seungyeon;Bae, Jeong Mo;Jeong, Seorin;Cho, Nam-Yun;Kang, Gyeong Hoon
    • 대한병리학회지
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    • 제52권6호
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    • pp.386-395
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    • 2018
  • Background: Previous studies on synchronous colorectal carcinoma (SCRC) have reported inconsistent results about its clinicopathologic and molecular features and prognostic significance. Methods: Forty-six patients with multiple advanced tumors (T2 or higher category) who did not receive neoadjuvant chemotherapy and/or radiotherapy and who are not associated with familial adenomatous polyposis were selected and 99 tumors from them were subjected to clinicopathologic and molecular analysis. Ninety-two cases of solitary colorectal carcinoma (CRC) were selected as a control considering the distributions of types of surgeries performed on patients with SCRC and T categories of individual tumors from SCRC. Results: SCRC with multiple advanced tumors was significantly associated with more frequent nodal metastasis (p=.003) and distant metastasis (p=.001) than solitary CRC. KRAS mutation, microsatellite instability, and CpG island methylator phenotype statuses were not different between SCRC and solitary CRC groups. In univariate survival analysis, overall and recurrence-free survival were significantly lower in patients with SCRC than in patients with solitary CRC, even after adjusting for the extensiveness of surgical procedure, adjuvant chemotherapy, or staging. Multivariate Cox regression analysis revealed that tumor multiplicity was an independent prognostic factor for overall survival (hazard ratio, 4.618; 95% confidence interval, 2.126 to 10.030; p<.001), but not for recurrence-free survival (p=.151). Conclusions: Findings suggested that multiplicity of advanced T category-tumors might be associated with an increased risk of nodal metastasis and a risk factor for poor survival, which raises a concern about the guideline of American Joint Committee on Cancer's tumor-node-metastasis staging that T staging of an index tumor determines T staging of SCRC.

한발 서기 발목 균형 운동과 목 안정화 운동이 전방 머리 자세를 가진 성인의 목 부위 정렬, 근육 및 혈관두께에 미치는 영향 (Effects of Single Leg Ankle Balance Exercise and Neck Stabilization Exercise on Neck Alignment, Muscle and Vascular Thickness in Adults with Forward Head Posture)

  • 윤삼원;김윤환;차영주
    • 대한통합의학회지
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    • 제12권3호
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    • pp.71-81
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    • 2024
  • Purpose : In this study, we compared the effects of ankle, McKenzie, and cervical stabilization exercises in individuals with a forward head posture. Outcome measures investigated included the neck disability index, craniovertebral angle (CVA), cranial rotation angle (CRA), and thickness of the longus colli muscle (LC) and carotid artery (CA) post-intervention. Methods : The study included 20 individuals with a forward head posture, who were assigned to an experimental group (EG, individuals performed ankle exercises) or control group (CG, individuals performed McKenzie and cervical stabilization exercises). The EG intervention was specifically designed to enhance proprioception in the ankle joint and strengthen the ankle muscles to improve overall stability and function. In contrast, CG interventions aimed to improve neck muscle balance and cervical spine alignment. Paired t-tests were used to analyze intragroup changes and independent t-tests to determine intergroup differences pre-and post-intervention. The significance level for all statistical tests was set at α=.05. Results : We observed significant post-intervention improvements in both groups, specifically, in the CVA, CRA, and LC and CA thickness (p<.05). These results indicate that ankle, McKenzie, and cervical stabilization exercises were useful for neck posture correction, improved muscle balance, and enhanced blood flow to the neck. Conclusion : This study underscores the positive effects of ankle, McKenzie, and cervical stabilization exercises in individuals with a forward head posture. Our study highlights the benefits of these exercises for posture correction and overall neck health and the clinical effectiveness and usefulness of ankle exercises as an important intervention to improve forward head posture.

유무선 통합 망에서 대량호 지능망 서비스의 성능 및 자원 최적화를 위한 동적 큐 관리자 (A Dynamic Queue Manager for Optimizing the Resource and Performance of Mass-call based IN Services in Joint Wired and Wireless Networks)

  • 최한옥;안순신
    • 한국통신학회논문지
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    • 제25권5B호
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    • pp.942-955
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    • 2000
  • 본 논문은 유무선 통합망 환경하에서 대량호에 근거한 지능망 서비스의 호 완료율을 증가시키고 자원을 최적화하기 위한 정보 흐름 및 총괄서비스 로직을 설계한다. 이 로직을 구현하기 위하여 지능망 서비스제거에 호대기 서비스 특징을 적용하기 위한 동적 큐 관리자를 제시하는데, 이것을 유선 가입자뿐만 아니라 이동 단말을 소유한 무선 가입자에게도 적용하기위해 홈위치등록기와 서비스제어기간에 해당 서비스 가입자들의 이동성을 큐 관리자에게 통보하기 위한 서비스 등록 여부 프래그를 관리한다. 따라서, 이동 서비스 가입자가 로밍함에 따른 동적 서비스 그룹핑을 수행하고 M/M/c/K 큐잉 모델에 근거한 큐 길이를 동적으로 관리하여 자원을 최적화 할 수 있는 동적 큐 관리 메커니즘을 제안한다. 동적 큐 관리자에 의해 할당된 큐 길이를 결정하기 위해 서비스 증가율에 따른 가입자 단말 수와 실패율간의 관계 및 그에 따른 큐에서의 적정 대기 시간을 시뮬레이션 및 분석한다. 또한, 동적 큐 관리자를 구성하는 내부 서비스 로직과 SIB들간의 상호동작 및 자료 구조를 설계 및 구현한다.

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체간 안정화 운동이 무릎관절 전치환술 환자의 무릎기능, 균형, 보행에 미치는 영향 (The Effects of Trunk Stability Exercise on Knee function, Balance, Gait in patients after Total Knee Arthroplasty)

  • 이재홍;민동기;이상재
    • 한국산학기술학회논문지
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    • 제19권2호
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    • pp.422-428
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    • 2018
  • 본 연구는 퇴행성 관절염으로 인해 무릎관절 전치환술을 실시한 환자를 대상으로 체간 안정화 운동이 무릎기능, 균형, 보행능력 향상에 어떠한 영향을 미치는지 알아보고자 한다. 본 연구 대상자는 퇴행성 관절염으로 진단 받아 무릎관절 전치환술을 실시한 환자 24명을 선정하여, 무작위 배분으로 일반 물리치료를 실시한 대조군 12명, 체간 안정화 운동을 실시한 실험군 12명으로 구성하였다. 체간 안정화 운동은 선행 연구를 참고하여 구성한 3가지 운동을 총 4주간 실시하였다. 측정도구로는 무릎기능 측정은 무릎관절 주관적 기능 점수 척도를, 균형능력은 일어나 걷기 검사, 한발 서기 검사를 보행능력은 10미터 걷기 검사를 이용하였다. 통계학적 분석은 각 그룹 내 비교는 대응표본 t-검정, 각 그룹 간 비교는 독립표본 t-검정으로 분석하였다. 본 연구 결과 중재 후 실험군이 대조군에 비해 모든 측정 결과가 유의하게 향상되어 나타났다(p<.05). 이와 같은 결과를 바탕으로 무릎관절 전치환술 환자를 대상으로 무릎관절 치료와 함께 체간 안정화 운동을 실시한다면, 환자의 무릎기능, 균형, 보행에 좀 더 효과적이라고 판단된다.

Railway Governance and Power Structure in China

  • Lee, Jinjing
    • International Journal of Railway
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    • 제1권4호
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    • pp.129-133
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    • 2008
  • Over the last $15{\sim}20$years, many countries have adopted policies of railway privatization to keep up with increasing competition from road and air transport. Although each country and case has its own history, market characteristics, political context as well as administrative process, railway privatizations (including railway restructure, concession etc.) in the west usually are accompanied with the establishment of new regulatory regimes. Therefore, railway governance has been innovating towards an interaction of government, regulator, industry bodies, user groups, trade unions and other interested groups within the regulatory framework. However, it is not the case in China. Although China had seen a partial privatization in some branch lines and is experiencing a much larger-scale privatization by establishing joint-ventures to build and operate high-speed passenger lines and implementing an asset-based securitization program, administrative control still occupies absolutely dominant position in the railway governance in China. Ministry of Railway (MOR) acts as the administrator, operator as well as regulator. There is no national policy that clearly positions railway in the transportation network and clarifies the role of government in railway development. There is also little participation from interested groups in the railway policy making, pricing, service standard or safety matter. Railway in China is solely governed by the mere executive agency. Efficiency-focused economic perspective explanation is far from satisfaction. A wider research perspective from political and social regime is of great potential to better explain and solve the problem. In the west, separation and constrains of power had long been established as a fundamental rule. In addition to internal separation of political power(legislation, execution and jurisdiction), rise of corporation in the 19th century and association revolution in the 20th century greatly fostered the growth of economic and social power. Therefore, political, social and economic organizations cooperate and compete with each other, which leads to a balanced and resonable power structure. While in China, political power, mainly party-controlled administrative power has been keeping a dominated position since the time of plan economy. Although the economic reform promoted the growth of economic power of enterprises, it is still not strong enough to compete with political power. Furthermore, under rigid political control, social organizations usually are affiliated to government, independent social power is still too weak to function. So, duo to the limited and slow reform in political and social regime in China, there is an unbalanced power structure within which political power is dominant, economic power expanding while social power still absent. Totally different power structure in China determines the fundamental institutional environment of her railway privatization and governance. It is expected that the exploration of who act behind railway governance and their acting strength (a power theory) will present us a better picture of railway governance as a relevant transportation mode. The paper first examines the railway governance in China and preliminarily establishes a linkage between railway governance and its fundamental institutional environment, i.e. power structure in a specific country. Secondly, the reason why there is no national policy in China is explored in the view of political power. In China, legislative power is more symbolic while party-controlled administrative power dominates political process and plays a fundamental role in Chinese railway governance. And then, in the part three railway finance reform is analyzed in the view of economic power, esp. the relationship of political power and economic power.

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큰느타리버섯 재배사의 실태분석 - 서부경남지역을 중심으로 - (Analysis of Actual State of Facilities for Pleurotus eryngii Cultivation - Based on Western Gyeongnam Area -)

  • 윤용철;서원명;유찬
    • 생물환경조절학회지
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    • 제13권4호
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    • pp.217-225
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    • 2004
  • 본 조사는 최근 급격히 증가하고 있는 새송이버섯 재배농가의 안정적 영농을 위해 재배사 설계, 시공 및 환경조절과 관련한 기초 자료를 마련하기 위해 서부 경남지역을 대상으로 새송이버섯 재배사의 재배사 규모, 환경조절시스템 등의 실태조사 및 검토를 하였다. 재배사의 형태는 반영구재배사와 영구재배사로 대별 할수 있었고, 반영구재배사는 대부분 단동이었고, 영구재배사의 경우는 단동에 비해 상대적으로 연동이 많았다. 그리고 재배사의 규모는 형태에 관계없이 다양하였지만, 길이, 폭 및 동고는 각각 20m, $6.6\~7.0m$$4.6\~5.0m$정도의 농가가 가장 많았으며, 동당 바닥면적은 $132\~140m^2$(40-42평)정도의 범위로서 대부분 콘크리트로 처리하여 각종 균에 의한 버섯의 오염을 방지 할 수 있도록 되어 있었다. 반영구 및 영구재배사의 지붕경사각은 각각 $41.5^{\circ}$$18.6\~28.6^{\circ}$로 나타나 반영구재배사의 지붕경사도가 더 큰 것으로 나타났다. 그리고 재배상의 폭 및 단수는 재배사의 형태에 관계없이 각각 $1.2\~1.6m$정도와 4단이 주류를 이루고 있었다. 버섯을 연중재배 하는 재배사에는 모두 냉${\cdot}$난방시설, 가습장치 및 환기팬이 설치되어 있었다. 난방방식의 경우, 온수보일러, 전기히터, 증기보일러 순으로 나타났다. 냉방장치의 경우는 모두 산업용 에어컨을 설치하여 운용하고 있었다. 그리고 가습은 초음파가습기와 원심분리가습기를 사용하고 있었으며, 보조 장치로 분무노즐을 사용하는 농가도 일부 있었다. 또한 온${\cdot}$습도 조절 및 탄산가스 조절을 위한 장치의 제어는 동별 제어시스템을 많이 채택하고 있었다. 그리고 온도센서 이외는 모두 타이머를 이용하고 있음을 알 수 있었다. 배지병의 크기는 850 cc 및 1,100 cc를 사용하는 농가가 주류를 이루고 있었고, 이 밖에도 800cc와 950 cc, 1,200 cc병을 사용하는 농가도 있었다. 출하형태는 대부분 유통회사와 공판장을 동시에 이용하고 있었다.

Transportation and Deposition of Modern Sediments in the Southern Yellow Sea

  • Shi, Xuefa;Chen, Zhihua;Cheng, Zhenbo;Cai, Deling;Bu, Wenrui;Wang, Kunshan;Wei, Jianwei;Yi, Hi-Il
    • Journal of the korean society of oceanography
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    • 제39권1호
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    • pp.57-71
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    • 2004
  • Based on the data obtained under the China-Korea joint project (1997-2001) and historic observations, the distribution, transportation and sedimentation of sediment in the southern Yellow Sea (SYS) are discussed, and the controversial formation mechanism of muddy sediments is also explored. The sediment transport trend analysis indicates that the net transport direction of sediment in the central SYS (a fine-grained sediment deposited area) points to $123.4^{\circ}E,\;35.1^{\circ}N$, which is a possible sedimentation center in the central SYS. The sediment transport pattern is verified by the distribution of total suspended matter (TSM) concentration and ${\delta}^{13}C$ values of particulate organic carbon (POC), the latter indicates that the bottom water plays a more important role than the surface water in transporting the terrigenous material to the central deep-water area of the SYS, and the Yellow Sea circulation is an important control factor for the sediment transport pattern in the SYS. The carbon isotope signals of organic matter in sediments indicate that the Shandong subaqueous delta has high sedimentation rate and the deposited sediments originate mainly from the modern Yellow River. The terrigenous sediments in deep-water area of the SYS originate mainly from the old Yellow River and the modern Yellow River, and only a small portion originates from the modern Yangtze River. The analytical results of TSM and stable carbon isotopes are further confirmed by another independent tracer of sediment source, polycyclic aromatic hydrocarbons (PAHs). Five light mineral provinces in the SYS can be identified and they indicate inhomogeneity in sources and sedimentary environment. The modern shelf sedimentary processes in the SYS are controlled by shelf dynamic factors. The muddy depositional systems are produced in the shelf low-energy environments, which are controlled by some meso-scale cyclonic eddies (cold eddies) in the central SYS and the area southwest of the Cheju Island. On the contrary, an anticyclonic muddy depositional system (warm eddy sediment) appears in the southeast of the SYS (the area northwest of the Cheju Island). In this study, we give the cyclonic and anticyclonic eddy sedimentation patterns.

제주 지역 간호사의 구강 악안면 영역 손상에 대한 응급 처치 인식도 (Cognition of registered nurse on emergency treatment for oral and maxillofacial injury in Jeju province)

  • 이병진;송효정;임길채;감세훈;김성준
    • 대한치과의사협회지
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    • 제50권12호
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    • pp.763-770
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    • 2012
  • The purposes of this work were to assess the cognition of the registered nurse(RN) on oral and maxillofacial emergency treatment and to compare cognition of the RN with that of the 119 emergency medical technician(EMT). 450 RNs who were working at each of secondary hospitals in Jeju province had responded to the questionnaire. Independent sample t-test and chi-square test were used to assess the state of RN on dental emergency treatment and to compare RN with EMT. The question 'education time on dentistry in formal education' that marked '0 hour' and '1-3 hours' were 73.3% and 20.0%, respectively. The question 'refresher training class on dentistry' that marked '0 hour' and '1-3 hours' were 92.9% and 6.7%, aggregately 99.6%. The results showed low score in the question 'reduction of temporo-mandibular joint(TMJ)'($1.67{\pm}0.857$), 'fixation of dislocated TMJ'($1.70{\pm}0.853$) and 'post-avulsed tooth treatment'($1.78{\pm}0.774$) by 5-point Likert scale. Likewise, the scores were $2.02{\pm}0.806$ in the question 'treatment of maxillofacial trauma', $2.76{\pm}1.061$ in the question 'emergent care of avulsed tooth', $2.70{\pm}1.095$ in the question 'treatment time of avulsed tooth' and $2.79{\pm}1.056$ in the question 'mouth guard', respectively. Compared to EMT, results of RN showed a statistically lower figure(p<0.05) in all items compared except the question 'medicine control', and the question 'doctor care in emergency room' was borderline(p=0.069). From this study, it is necessary for RN and student of nursing science to be educated on the oral and maxillofacial emergency treatment for the initial management of injuries. Authors suggest further co-study and nation-wide research with nursing care.