• 제목/요약/키워드: effective angle

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전기 도금법으로 제작한 Ni 박막의 강자성 공명 선폭 분석 (Analysis of Ferromagnetic Resonance Linewidth in Ni Thin Film Fabricated by Electrodeposition Method)

  • 김동영;윤석수
    • 한국자기학회지
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    • 제24권2호
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    • pp.60-65
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    • 2014
  • 전기 도금법으로 제작한 Ni 박막(240 nm)의 자기장 각도에 따른 강자성 공명 신호를 측정하여 공명 자기장($H_{res}$) 및 선폭(${\Delta}H_{PP}$)을 도출하였다. 자기장 각도에 따른 $H_{res}$는 이론적인 분석 결과와 일치하였으며 이들 결과로부터 제조된 Ni 박막의 g-factor는 2.18임을 확인하였다. 자기장 각도에 따른 ${\Delta}H_{PP}$는 박막의 수평 방향에서 매우 큰 값을 나타냈으며, 이러한 특성은 Gilbert 감쇠에 기인하는 균일한 선폭 특성과 약 1 nm의 표면에서 나타나는 자구들의 각도 변화 및 자화량 변화에 기인하는 비균일한 선폭 특성으로는 설명되지 않았다. 따라서 본 연구에서는 박막의 두께가 10 GHz에서 임계 두께(약 50 nm) 이상으로 증가하면 나타나는 two magnon scattering 이론을 적용하여 비균일한 선폭 특성을 분석하였다. 이러한 분석 결과로부터 전기 도금법으로 제작한 240 nm 두께를 갖는 Ni 박막에서 각도에 따른 비균일한 선폭 변화의 주요한 원인은 재료 내부 결함들에 의한 스핀파 산란이었음을 알 수 있었다.

Positional change in mandibular condyle in facial asymmetric patients after orthognathic surgery: cone-beam computed tomography study

  • Choi, Byung-Joon;Kim, Byung-Soo;Lim, Ji-Min;Jung, Junho;Lee, Jung-Woo;Ohe, Joo-Young
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제40권
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    • pp.13.1-13.8
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    • 2018
  • Background: We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry. Methods: Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively. Results: On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A. Conclusions: There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

뉴미디어 환경과 언론인 직업 규범의 변화: 리영희 언론정신을 통한 탐색연구 (The Change of Media and Emerging Journalistic Norm and Value: An exploration Based on the Young-hee Rhee's Idea)

  • 이봉현
    • 한국언론정보학보
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    • 제59권
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    • pp.31-49
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    • 2012
  • 디지털 미디어 기술 발달에 따라 언론인의 직업 규범과 가치가 어떻게 변하고 있는 지를 탐구하는 것이 이 논문의 목적이다. 먼저, 19세기 말 이래 확립된 객관주의, 전문직주의 언론 규범이 새로운 미디어 생태계에서 어떤 변화의 압력을 받고 있는 지를 파악했다. 미디어 환경의 변화는 직업 언론인의 직무 수행에 $\triangle$ 인식론 측면 $\triangle$ 전문직 정체성의 측면 $\triangle$ 독자와의 상호작용 측면에서 변화를 주고 있는 것으로 나타났다. 이어 한국의 역사적 사회적 맥락에서 형성돼 공유되고 있는 언론 규범에 이런 일반적인 변화가 어떻게 투영되고 있는지를 중견 언론인들을 심층 인터뷰 해 조사했다. 인터뷰에 앞서 언론인들로 부터 '기자 정신'의 역할 모델로 인정받는 리영희 선생(1929~2010)의 언론사상을 도출해 비교의 준거로 활용했다. 즉, 이 연구는 $\triangle$실증적 글쓰기를 통한 실체적 진실 추구 $\triangle$전문성에의 열정 $\triangle$독자(민중) 와의 상호교육 등 리영희의 언론 정신으로 상징되는 한국적 언론 규범이 현재의 미디어 환경에서 어떻게 변화해 가고 있는 지를 살펴보는 탐색적 연구이다. 연구결과, 미디어 환경 변화에도 불구하고 언론인들은 실체적 진실추구, 전문성 추구, 심층 탐사보도 등 리영희의 언론정신으로 상징되는 전통 저널리즘의 규범과 가치가 직무 수행에서 여전히 중요한 지침이 된다고 보았다. 또 이런 정신이 현재 한국 저널리즘이 봉착한 위기를 극복하는 데도 긴요하다고 인식하고 있었다. 다만, 언론인들은 디지털 시대에는 이런 저널리즘의 가치를 열린 자세로 수용자와 밀접히 상호작용 함으로써 성취해야 한다고 인식하고 있었다. 진실을 가려 내 제시하는 '판별자'의 역할, 시민저널리스트와 전문가 블로거의 자원을 폭넓게 활용해 뉴스를 생산하는 '네트워크 연결점', 수많은 정보를 엮고 정리하는 '뉴스 코디네이터' 등으로 역할을 확장하는 등 새로운 미디어 기술이 제공하는 환경 변화에 능동적으로 대처해야 할 것으로 지적됐다.

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점성토(粘性土)의 응력(應力) - 변형(變形) 추정(推定)에 관(關)한 연구(硏究) (A Study on the Stress-Strain Prediction of Silty Clay)

  • 조성섭;강예묵;정성규;윤현정
    • 농업과학연구
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    • 제19권1호
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    • pp.65-78
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    • 1992
  • 본(本) 연구(硏究)는 당진지방(唐津地方)의 해성(海成)실트질 점성토(粘性土)를 채취하여 물리적(物理的) 실험(實驗) 및 삼축압축시험(三軸壓縮試驗)을 실시하고, 그 시험결과로 쌍곡선식(雙曲線式) 매개상수(媒介常數)를 구한 후, 쌍곡선식(雙曲線式) 모형(模型)에 의한 응력일변형관계(應力一變形關係)를 검토하여 점성토(粘性土)의 응력일변형(應力一變形)을 추정하여 다음과 같은 결과(結果)를 얻었다. 1. 건조밀도(乾燥密度) 및 함수비(含水比)의 증가(增加)에 따른 탄성계수(彈性係數)는 건조밀도(乾燥密度)에 비례하고, 함수비(含水比)는 반비례하였다. 2. 쌍곡선식(雙曲線式) 모형(模型)에 가장 많은 영향을 미치는 인자는 적압력(積壓力)과 건조밀도(乾燥密度)이었고, 점착력과 내부마찰각(內部摩擦角)은 이보다 적은 영향(影響)을 타나났다. 3. 통계적(統計的) 방법(方法)의 추정치를 쌍곡선식(雙曲線式)에 의한 추정치와 비교하였으나, 통계적(統計的) 추정치가 쌍곡선식(雙曲線式) 모형(模型)에 의한 추정치보다 낮게 나타났다. 4. 많은 그림과 계산과정(計算過程)을 단순화하여 시간적 노력을 줄이는 실용적(實用的) 전산(電算)프로그램을 작성하였으나, 입력되는 기초정수(基礎定數)의 시험오차(試驗誤差)를 없애는 것이 중요하다.

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발목관절 테이핑이 고령자의 균형능력에 미치는 영향 (The Effect of Ankle Joint Taping on Balance in the Elderly)

  • 이경순;이영빈;최익준;송하영;박주은;구현주;김부성;김영옥;하수종;김양지;권남정;이세인
    • 대한물리치료과학회지
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    • 제19권3호
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    • pp.49-56
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    • 2012
  • Background : The purpose of this study is to understand the effects of ankle joint taping on balancing abilities of the elderly and to provide preliminary data on preventing falls among the elderly. Methods : In this study, 20 students(8 male, 12 female) in their 20s from D University as well as 14 elderly(4 male, 10 female) in their 70s from S community center have participated. The participants were well informed about the experiment and voluntarily participated. We measured the difference in balancing ability before and after taping between the two groups using methods such as standing on single-leg stance, TUG, and plantar pressure. Kinesio taping, a stop-watch, and the EMED-system were used as equipment along with the SPSS 12.0 program, with a significance level of 0.05, to test the difference before and after taping between the two groups. Result : First, the 70s group showed a significant increase in the dorsal flexion angle after taping. Second, the 70s group showed a significant increase in duration time of standing on one foot after taping. Third, the 70s group's TUG time was significantly shorter. Fourth, the maximum peak value for static and dynamic plantar pressure showed a significant decrease after taping; and dynamic plantar pressure area value decreased as well within significant range. Conclusion : The study has shown that taping is effective on static dynamic balancing ability of the elderly.

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제주도 북서부 지역 화산암체의 지질공학 특성 (Engineering Geological Characteristics of volcanic rocks of the Northwestern Cheju Island, Korea)

  • 김영기;최옥곤
    • 지질공학
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    • 제1권1호
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    • pp.19-37
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    • 1991
  • 제주도 북서부 지역의 지질은 제4기 플라이스토세에서 홀로세에 형성된 현무암류의 용암체와, 해안변을 따라 분포하는 화산쇄층성 집적층인 성산층, 그리고 기생화산(cindercone)이 30 여개나 분포하고 있다. 이 현무암류(표선리 및 시흥리 현무암 등)들은 주상절리가 심히 발달하고, 다량의 기공을 형성하고 있다. 이 용암들 사이에는 용암공동(lavacave)이 발달하고 있으며, 용암공동에는 화산쇄층물 및 점토층이 협재되어 있다. 내재물들이 지하수에 의해 유거되면, 주상절리가 발달된 이 용암체는 부식, 함역 및 침하를 일으킨다. 특히 이들 용암체의 기공상(크기, 모양, 방향성)은 암체의 공학적 성질(암석의 강도 등)을 좌우하게 된다. 이 기공상은 본 현무암체의 피상강도지배요소가 되어, 이 암체에 대한 유효강도비(Ke, Ke=0.30-0.72)를 도출하였다. 여기서 Ke값이 적을수록 낮은 내부응력을 의미한다. 본역에서는 저위지편보다 고위지편일수록 암체강도가 낮은 성향을 보인다. 또한 피상강도각($\phi$)은 $\phi$=30$^{\circ}$-$10^{\circ}$의 범위로서, 본 화산암체는 대체로 낮은 피상강도각을 나타내고 있다. 따라서 본 암체의 피상 극한한계치인 0.33을 기준으로 할 때, 거의 대부분이 Ke>0.33이 되어 지질공학적 불안정영역에 속하는 암체라 할 수 있다.

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굴절법 탄성파탐사 현장에서 GRM을 이용한 청주화강암지역 기반암 깊이의 신속한 추정 (Fast Delineation of the Depth to Bedrock using the GRM during the Seismic Refaction Survey in Cheongju Granite Area)

  • 이선중;김지수;이철희;문윤섭
    • 자원환경지질
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    • 제43권6호
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    • pp.615-623
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    • 2010
  • 굴절법 탄성파탐사는 직접파와 임계굴절파를 이용하여 지하의 속도구조를 파악하는 지구물리탐사방법이다. GRM은 해석기법 중의 하나로서 수개의 정방향 및 역방향 발파의 주행시간을 이용하여 경사면은 물론 저속도층이나 얇은 층과 같은 숨은 층 하부에 대한 정보까지 제공한다. 이 연구에서는 5~7점 발파가 수행된 후 실내 자료처리 작업이 진행되는 일발적인 조사와 달리, 신축부지의 터파기 과정 및 시추자료에서 해석된 풍화대/기반암의 2층 구조를 대상으로 현장에서 간단히 양단발파 자료만을 가지고 엑셀 기반의 GRM을 적용시켜 풍화대와 기반암의 경계면을 신속히 파악할 수 있는지 살펴보았다. 이 방법의 적용효과와 계산의 신뢰도를 확인하기 위해 정사각과 속도대비 변화에 따른 각 모형에 대한 적용성을 검토한 결과 각각 최대 약 $30^{\circ}C$의 경사와 최대 0.6의 속도대비가 되는 경계면을 해석할 수 있는 것으로 나타났다. 청주화강암체에 대한 실제 현장탐사에서 해석된 기반암까지의 깊이는 시추자료 및 SPS 검층 자료에서 도출된 연암 상부의 표면과 잘 상관되었다. 실제 현장에서 기반암까지의 깊이를 간편한 엑셀-GRM을 이용하여 신속히 추정할 수 있다는 점에서 기반암의 깊이가 심하게 변하지 않은 좁은 지역에서의 풍화대 조사 및 이에 따른 저비용의 탐사설계에 일정한 역할을 할 것으로 보인다.

역도 인상동작 성공 시 최대 바벨무게 예측 (The Forecasting a Maximum Barbell Weight of Snatch Technique in Weightlifting)

  • 하종규;류지선
    • 한국운동역학회지
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    • 제15권3호
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    • pp.143-152
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    • 2005
  • The purpose of this study was to predict the failure or success of the Snatch-lifting trial as a consequence of the stand-up phase simulated in Kane's equation of motion that was effective for the dynamic analysis of multi-segment. This experiment was a case study in which one male athlete (age: 23yrs, height: 154.4cm, weight: 64.5kg) from K University was selected The system of a simulation included a multi-segment system that had one degree of freedom and one generalized coordinate for the shank segment angle. The reference frame was fixed by the Nonlinear Trans formation (NLT) method in order to set up a fixed Cartesian coordinate system in space. A weightlifter lifted a 90kg-barbell that was 75% of subject's maximum lifting capability (120kg). For this study, six cameras (Qualisys Proreflex MCU240s) and two force-plates (Kistler 9286AAs) were used for collecting data. The motion tracks of 11 land markers were attached on the major joints of the body and barbell. The sampling rates of cameras and force-plates were set up 100Hz and 1000Hz, respectively. Data were processed via the Qualisys Track manager (QTM) software. Landmark positions and force-plate amplitudes were simultaneously integrated by Qualisys system The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 9Hz calculated with Andrew & Yu's formula. The input data of the model were derived from experimental data processed in Matlab6.5 and the solution of a model made in Kane's method was solved in Matematica5.0. The conclusions were as follows; 1. The torque motor of the shank with 246Nm from this experiment could lift a maximum barbell weight (158.98kg) which was about 246 times as much as subject's body weight (64.5kg). 2. The torque motor with 166.5 Nm, simulated by angular displacement of the shank matched to the experimental result, could lift a maximum barbell weight (90kg) which was about 1.4 times as much as subject's body weight (64.5kg). 3. Comparing subject's maximum barbell weight (120kg) with a modeling maximum barbell weight (155.51kg) and with an experimental maximum barbell weight (90kg), the differences between these were about +35.7kg and -30kg. These results strongly suggest that if the maximum barbell weight is decided, coaches will be able to provide further knowledge and information to weightlifters for the performance improvement and then prevent injuries from training of weightlifters. It hopes to apply Kane's method to other sports skill as well as weightlifting to simulate its motion in the future study.

핵심역량 지향성과 프로세스 관리역량이 IT 아웃소싱 성과에 미치는 연구 (An Empirical Investigation into the Role of Core-Competency Orientation and IT Outsourcing Process Management Capability)

  • 김용진;남기찬;송재기;구철모
    • Asia pacific journal of information systems
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    • 제17권3호
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    • pp.131-146
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    • 2007
  • Recently, the role of IT service providers has been enlarged from managing a single function or system to reconstructing entire information management processes in new ways to contribute to shareholder value across the enterprise. This movement toward extensive and complex outsourcing agreements has been driven by the assumption that outsourcing information technology functions is a reliable approach to maximizing resource productivity. Hiring external IT service providers to manage part or all of its information-related services helps a firm focus on its core business and provides better services to its clients, thus obtaining sustainable competitive advantage. This practice of focusing on the strategic aspect of outsourcing is referred to as strategic sourcing where the focus is capability sourcing, not procurement. Given the importance of the strategic outsourcing, however, to our knowledge, there is little empirical research on the relationship between the strategic outsourcing orientation and outsourcing performance. Moreover, there is little research on the factor that makes the strategic outsourcing effective. This study is designed to investigate the relationship between strategic IT outsourcing orientation and IT outsourcing performance and the process through which strategic IT outsourcing orientation influences outsourcing performance, Based on the framework of strategic orientation-performance and core competence based management, this study first identifies core competency orientation as a proper strategic orientation pertinent to IT outsourcing and IT outsourcing process management capability as the mediator to affect IT outsourcing performance. The proposed research model is then tested with a sample of 200 firms. The findings of this study may contribute to the literature in two ways. First, it draws on the strategic orientation - performance framework in developing its research model so that it can provide a new perspective to the well studied phenomena. This perspective allows practitioners and researchers to look at outsourcing from an angle that emphasizes the strategic decision making to outsource its IT functions. Second, by separating the concept of strategic orientation and outsourcing process management capability, this study provides practices with insight into how the strategic orientation can work effectively to achieve an expected result. In addition, the current study provides a basis for future studies that examine the factors affecting IT outsourcing performance with more controllable factors such as IT outsourcing process management capability rather than external hard-to-control factors including trust and relationship management. This study investigates the major factors that determine IT outsourcing success. Based on strategic orientation and core competency theories, we develop the proposed research model to investigate the relationship between core competency orientation and IT outsourcing performance and the mediating role of IT outsourcing process management capability on IT outsourcing performance. The model consists of two independent variables (core-competency-orientation and IT outsourcing process management capability), and two dependent variables (outsourced task complexity and IT outsourcing performance). Comprehensive data collection was conducted through an outsourcing association. The survey data were analyzed using a structural analysis method. IT outsourcing process management capability was found to mediate the effect of core competency orientation on both outsourced task complexity and IT outsourcing performance. Further analysis and findings are discussed.

단일 분절 퇴행성 경추질환에서 Titanium Cage를 이용한 전방 융합술의 조기 치험 : 골편 이식을 동반하지 않은 경우의 임상적 방사선학적 초기 결과 (Preliminary Experience with Cervical Implantable Titanium Cage(RABEA) in Patients with Monosegmental Degenerative Disease : Clinical and Radiological Outcomes without Cancellous Bone Filling into Cage)

  • 이영균;한영민;김종태;정동섭;박영섭;박춘근;강준기
    • Journal of Korean Neurosurgical Society
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    • 제30권sup2호
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    • pp.300-308
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    • 2001
  • Objectives : Anterior cervical discectomy and interbody fusion has become a well-accepted surgical treatment of degenerative cervical diseases. Implatable cages have a stabilizing effect without plates and no need for autogenous bone graft. The authors evaluates the effect of implatable titanium cage(RABEA) on the clinical and radiological outcomes. Methods : 34 patients with symptomatic cervical degenerative diseases due to one level disc pathology were underwent anterior cervical discectomy and interbody fusion with titanium cages(RABEA) which were not filled with cancallous bone grafts from January 1999 to May 2001. Patients with osteoporosis and older than 65 years were not included. Among them, 15 patients could be followed-up for at least 1 year. The authors retrospectively reviewed the charts and radiographic data. Mean follow-up period was $1.3{\pm}0.2years$. Results : Clinical results according to the Odom's criteria was exellent and good in 14(93%) patients. One patient with fair result showed complete loss of the disc space height due to settlement of the cage. Preoperatively, the mean height of the disc space(${\pm}$standard deviation) was $3.42{\pm}1.10mm$(range 2.0-5.5mm), and at 1 day postoperatively it was $7.88{\pm}0.90mm$(range 6.50-9.0). The mean height of the disc space after 1 year was $6.50{\pm}1.38mm$(range 3.0-8.0). The restoration of the height was statistically significant(p<0.05). The mean height after 1 year was $82.7{\pm}15.9%$ of the height at 1 day postoperatively. Preoperatively the mean value of the cervical lodortic angle was $21.8{\pm}11.8^{\circ}$ and 1 year postopertively, it was $24.5{\pm}8.3^{\circ}$, which was statistically not significant. All patients showed no abnormal movements on flexion and extension lateral film after 6 months. Conclusion : Implantable titanium cages appear safe and effective in selected patients, and their use helps to avoid complications associated with bone graft harvest. Subsidence of the cage seems to be a potential risk factor for recurrence of the symptoms. For long-term results, a longer follow-up is required.

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