• 제목/요약/키워드: tipping point

검색결과 36건 처리시간 0.211초

인간의 성 반응에 대한 모델 (Models of Sexual Response in Humans)

  • 최인광
    • 생물정신의학
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    • 제20권3호
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    • pp.66-73
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    • 2013
  • Sexual behavior is crucial in life, yet comparatively little is known about the mechanisms in the sexual response in humans. A lot of theories and models have been developed to explain about the process of the sexual response in humans. The first model of sexual function was described by Masters and Johnson, defined the four-phase model (phases of excitation, plateau, orgasm and resolution). Helen Kaplan proposed a slightly different model of human sexual response by adding the conception of the desire phase. Some years later, a new model of circular sexual response pattern was described by Whipple and Brash-McGreer, who acknowledged the cyclic nature of women's sexual response. Basson presented an alternative model of women's normative sexual function, which featured a responsive form of desire in women's sexual response. Bancroft developed a new theoretical model, the Dual Control Model, which postulates sexual response and arousal is ultimately determined by the balance between the sexual activation or excitation system and the sexual inhibition system. The Sexual Tipping Point is a model created by Perelman, suggesting that a sexual response is determined by a balance between excitatory or inhibitory factors that may be psychological, organic, psychosocial, or cultural. A comprehensive understanding of sexual response and function is of paramount importance for the psychiatrist to study sex, offer counseling to the patient on sex, and practice sex therapy. In this literature, models of sexual response would be reviewed to understand the knowledge of the sexual functioning in humans.

다물체 동역학 프로그램과 ZMP 이론을 이용한 고소작업차량의 전도 안정성 판별에 관한 연구 (A Study on the Determination of the Tip-Over Stability of High Place Operation Car Using Multibody Dynamics Program and ZMP)

  • 김상원;정창조;이정환;강동명;박문호
    • 한국기계가공학회지
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    • 제17권2호
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    • pp.145-152
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    • 2018
  • This study deals with the method of determining the tip-over stability of a truck mounted on a high place operation car that is frequently used to carry out high-altitude work. Multibody Dynamics Program and Zero Moment Point (ZMP) theory are used to include dynamic effects during the car's high place operation. Through a combination of the Multibody Dynamics Program and ZMP, understanding the dynamic effects of the car's operating parts and building a detailed tip-over model of the car permitted a more precise prediction of the car's tipping-over behavior. It is also expected to help reduce the car's development time due to the time-effective simulation and provide safer work levels for the operating guide (in terms of working radius and lifting capability) with the dynamics effects.

Maxillary expansion with the memory screw: a preliminary investigation

  • Halicioglu, Koray;Kiki, Ali;Yavuz, Ibrahim
    • 대한치과교정학회지
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    • 제42권2호
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    • pp.73-79
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    • 2012
  • Objective: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. Methods: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was $7.52{\pm}1.04$ days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. Results: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. Conclusions: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even aft er 6 months of retention.

상악 전치부 후방 견인 시 이동 양상과 응력 분포에 관한 삼차원 유한요소법적 연구 (The pattern of movement and stress distribution during retraction of maxillary incisors using a 3-D finite element method)

  • 정애진;김운수;이수행;강성수;최희인;조진형;김상철
    • 대한치과교정학회지
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    • 제37권2호
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    • pp.98-113
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    • 2007
  • 상악 전치부 후방 견인 시의 이동 양상 및 응력 분포를 건조 두개골을 전산화 단층 촬영에 의해 3차원 영상화한 유한 요소 모델 상에서 알아보고자 하였다. 피질골 절단술의 시행 여부와 고정원, 힘의 작용점을 각기 달리 설정하여 8개의 실험군을 구성하여 비교하였다. 통상적인 T-loop을 이용하여 공간폐쇄를 하는 경우 전치부는 후하방으로 경사이동 하였으며, 구치부에서도 약간 전방 이동하였다. 피질골 절단술을 동반하여 전치부를 견인한 경우, 전치부 골편에서의 응력 분포가 전반적으로 넓게 분포되었으며, 전치부 경사의 정도가 적은 반면에 변위량은 훨씬 더 많았다. 협측에서의 견인 시 상악 협측에 식립된 미니 임플랜트와 견치 Power arm간에 견인력을 가한 경우가 미니 임플랜트로 고정원이 강화된 제2소구치와 견치 브라켓 간에 견인력을 가한 경우보다 전치부의 후하방 경사 정도가 적었다. 구개측에서 Powerarm에 대한 견인 시 정중구개봉합 부위에 식립한 미니 임플랜트로부터 견인력을 가한 경우가 상악 제1, 2대구치 간 구개면에 식립된 미니 임플랜트로부터 견인력을 가한 경우보다 전치부의 후하방 경사 정도가 컸다. 이러한 결과로써 치아이동 시 피질골 절단술의 효과와 저항중심에 대한 교정력 벡터 조정의 의미를 확인할 수 있었다.

Hydrological Consequences of Converting Forestland to Coffee Plantations and Other Agriculture Crops on Sumber Jaya Watershed, West Lampung, Indonesia

  • Manik, Tumiar Katarina;Sidle, Roy Carl
    • Journal of Forest and Environmental Science
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    • 제34권4호
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    • pp.293-303
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    • 2018
  • Sumber Jaya (54,194 hectares) is a district in West Lampung, Indonesia, located at the upper part of Tulang Bawang watershed. This watershed is one major water resource for Lampung Province, but has become a focal point of discussion because of the widespread conversion of forestland to coffee plantations and human settlements which lead to environmental and hydrological problems. This research aimed to evaluate Sumber Jaya watershed affecting by rapid land use change using hydrological methods as a base for watershed management. Nested catchment structure consisted of eight sub-catchments was employed in this research to assess scaling issues of land use change impacts on rainfall-runoff connections. Six tipping bucket rain gages were installed on the hill slopes of each sub-catchment and Parshall flumes were installed at the outlets of each sub-catchment to monitor stream flow. First, unit hydrograph that expressed the relationship of rainfall and runoff was computed using IHACRES model. Second, unit hydrograph was also constructed from observations of input and response during several significant storms with approximately equal duration. The result showed that most of the storm flow from these catchments consisted of slow flow. A maximum of about 50% of the effective rainfall became quick flow, and only less than 10% of remaining effective rainfall which was routed as slow flow contributed to hydrograph peaks; the rest was stored. Also, comparing peak responses and recession rates on the hydrograph, storm flow discharge was generally increased slowly on the rising limb and decreased rapidly on the falling limb. These responses indicated the soils in these catchments were still able to hold and store rain water.

경영자과신이 주가급락위험에 미치는 영향 (The Effect of Managerial Overconfidence on Crash Risk)

  • 유혜영
    • 산경연구논집
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    • 제8권5호
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    • pp.87-93
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    • 2017
  • Purpose - This paper investigates whether managerial overconfidence is associated with firm-specific crash risk. Overconfidence leads managers to overestimate the returns of their investment projects, and misperceive negative net present value projects as value creating. They even use voluntary disclosures to convey their optimistic beliefs about the firms' long-term prospects to the stock market. Thus, the overconfidence bias can lead to managerial bad news hoarding behavior. When bad news accumulates and crosses some tipping point, it will come out all at once, resulting in a stock price crash. Research design, data and methodology - 7,385 firm-years used for the main analysis are from the KIS Value database between 2006 and 2013. This database covers KOSPI-listed and KOSDAQ-listed firms in Korea. The proxy for overconfidence is based on excess investment in assets. A residual from the regression of total asset growth on sales growth run by industry-year is used as an independent variable. If a firm has at least one crash week during a year, it is referred to as a high crash risk firm. The dependant variable is a dummy variable that equals 1 if a firm is a high crash risk firm, and zero otherwise. After explaining the relationship between managerial overconfidence and crash risk, the total sample was divided into two sub-samples; chaebol firms and non-chaebol firms. The relation between how I overconfidence and crash risk varies with business group affiliation was investigated. Results - The results showed that managerial overconfidence is positively related to crash risk. Specifically, the coefficient of OVERC is significantly positive, supporting the prediction. The results are strong and robust in non-chaebol firms. Conclusions - The results show that firms with overconfident managers are likely to experience stock price crashes. This study is related to past literature that examines the impact of managerial overconfidence on the stock market. This study contributes to the literature by examining whether overconfidence can explain a firm's future crashes.

Solar Photovoltaics Technology: No longer an Outlier

  • Kazmerski, Lawrence L.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.70-70
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    • 2011
  • The prospects of current and coming solar-photovoltaic (PV) technologies are envisioned, arguing this solar-electricity source is beyond a tipping point in the complex worldwide energy outlook. Truly, a revolution in both the technological advancements of solar PV and the deployment of this energy technology is underway; PV is no longer an outlier. The birth of modern photovoltaics (PV) traces only to the mid-1950s, with the Bell Telephone Laboratories' development of an efficient, single-crystal Si solar cell. Since then, Si has dominated the technology and the markets, from space through terrestrial applications. Recently, some significant shift toward technology diversity have taken place. Some focus of this presentation will be directed toward PV R&D and technology advances, with indications of the limitations and relative strengths of crystalline (Si and GaAs) and thin-film (a-Si:H, Si, Cu(In,Ga)(Se,S)2, CdTe). Recent advances, contributions, industry growth, and technological pathways for transformational now and near-term technologies (Si and primarily thin films) and status and forecasts for next-generation PV (nanotechnologies and non-conventional and "new-physics" approaches) are evaluated. The need for R&D accelerating the now and imminent (evolutionary) technologies balanced with work in mid-term (disruptive) approaches is highlighted. Moreover, technology progress and ownership for next generation solar PV mandates a balanced investment in research on longer-term (the revolution needs revolutionary approaches to sustain itself) technologies (quantum dots, multi-multijunctions, intermediate-band concepts, nanotubes, bio-inspired, thermophotonics, ${\ldots}$ and solar hydrogen) having high-risk, but extremely high performance and cost returns for our next generations of energy consumers. This presentation provides insights to the reasons for PV technology emergence, how these technologies have to be developed (an appreciation of the history of solar PV)-and where we can expect to be by this mid-21st century.

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지속가능개발과 물 안보 (Understanding Sustainable Development Goals and Water Security)

  • 박지현;홍일표
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2016년도 학술발표회
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    • pp.76-76
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    • 2016
  • 2015년은 국제사회 거버넌스 및 정책 패러다임에 있어 전환점(tipping point)을 맞는다. 2000년 국제사회가 인류의 빈곤 퇴치라는 삶에 가장 절대적인 개발목표로 2015년까지 달성해야 할 빈곤, 의료, 교육 등 사회 환경 현안에서 해결해야 할 단순명료한 목표를 제시하였다. 그리고 2015년 9월 UN 지속가능 세계정상 회의(World Summit on Sustainable Development, WSSD)에서는 지속가능개발목표(Sustainable Development Goals, SDGs)를 채택하여 2030년까지 전 세계가 경제성장, 기후 변화 등 경제적, 사회적, 환경적 측면을 통합적으로 고려하여 지속가능한 인간정주환경을 조성하자는데 합의를 마쳤다. 17개의 지속가능개발목표와 부속적으로 169개의 타겟이 설정되었으며, SDGs 안에서는 MDGs의 기조를 유지하면서, 인간의 권리 구현과 성평등, 여성과 어린이의 권리 신장 등을 포함하고 있으며, 기후변화와 예측이 불확실한 다양한 자연재난, 특히 물과 물 관련 재해가 빈곤 경감, 기후변화 대응, 인간정주의 모든 삶의 영역에 연계요소로 녹아 있다. 기후변화 적응과 물 안보, 특히 위기관리의 맥락이 내재되어 있는 2030년을 목표로 하는 국제사회의 Post-2015 개발의제에서 물 분야는 무엇보다 중요한 관심 분야로 부각이 되어 있다. 17개의 지속가능개발목표에서 SDG6을 "모두를 위한 물과 위생의 지속가능한 관리와 이용(Ensure availability and sustainable management of water and sanitation for all)"으로 하고 수자원관리 및 물과 위생 분야의 중요성을 전세계가 공감하고 함께 해결해 나가야 함을 강조하였다. 그러나 실질적으로는 물을 직접적으로 언급한 6번째 목표뿐만 아니라, 빈곤의 근절(SDG1), 기아근절과 지속가능한 농업의 증진(SDG2)을 비롯한 다양한 목표들에서 물 분야가 직접?간접적으로 연계 되어 있으며, 특히 기후변화의 영향으로 더욱 심각해진 물관련 재해로부터 리질리언스 확보 등, 지속가능개발목표의 전반적인 기조에서 물안보 확보를 읽을 수 있다. 물 분야에서 지속가능개발목표의 이행을 위한 노력은 국제사회의 물 문제 해결에 공동으로 대응하기 위한 글로벌 동반 성장 지원체계를 구축하기 위한 초석이 될 것이다.

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패러다임 전환에 의한 기업 측면의 IoT 경영 프로세스 구축방안 연구 (A Study on the establishment of IoT management process in terms of business according to Paradigm Shift)

  • 정민의;유성진
    • 지능정보연구
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    • 제21권2호
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    • pp.151-171
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    • 2015
  • 본 연구는 최근 가장 큰 이슈로 떠오르는 "사물인터넷(IoT: Internet of Things)"의 개념과 국내 외 IoT 시장에 대한 현황을 고찰하였으며, IoT 시대의 도래로 인해 유발되는 패러다임 전환 발생에 따른 기업측면의 적절한 대응방안에 대한 해결책을 도출하였다. 따라서 본 연구는 티핑포인트(Tipping point)에 있는 IoT 경쟁 시대에 적절하게 대응하기 위한 기업의 경영전략을 '패러다임 전환(paradigm shift)'이라는 시각을 통해 대응 방안을 제시하였다. 특히, 과거의 경영 패러다임과 IoT 시대의 경영 패러다임을 비교 분석하여 i)지식 및 학습 주도 경영, ii)기술 및 혁신 중심 경영, iii)수요 창출 경영, iv)글로벌 협업 경영으로 새롭게 패러다임 전환(Paradigm Shift)이 발생할 것으로 예측 및 제안하였고, 이러한 패러다임의 전환에 대응하기 위한 기업측면의 경영전략 프로세스 모델을 구축하기 위해 Gartner가 제시한 'RTE Cyclone model'을 활용하였다. '실시간 기업(RTE)' 이라는 개념은 급변하는 IoT 시대에 기업측면의 경영 전략 프로세스로 활용가치가 있다고 판단되며, 본 연구에서 적절히 응용하여 'IoT-RTE Cyclone model'을 제안하였다. 특히, 제안한 모델은 기업의 민첩성을 강조하고 IT 및 IoT 기술을 통한 실시간 모니터링, 분석, 실행을 기본으로 하며, 기업의 경영 프로세스 각 부문을 통합시켜 기업의 전반적인 서비스를 지원하기 때문에 빠르게 변화하는 IoT 시대에서 영위하는 기업측면에서의 효과적인 대응전략으로 활용할 수 있다.

Cone-beam computed tomographic evaluation of mandibular incisor alveolar bone changes for the intrusion arch technique: A retrospective cohort research

  • Lin Lu;Jiaping Si;Zhikang Wang;Xiaoyan Chen
    • 대한치과교정학회지
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    • 제54권2호
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    • pp.79-88
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    • 2024
  • Objective: Alveolar bone loss is a common adverse effect of intrusion treatment. Mandibular incisors are prone to dehiscence and fenestrations as they suffer from thinner alveolar bone thickness. Methods: Thirty skeletal class II patients treated with mandibular intrusion arch therapy were included in this study. Lateral cephalograms and cone-beam computed tomography images were taken before treatment (T1) and immediately after intrusion arch removal (T2) to evaluate the tooth displacement and the alveolar bone changes. Pearson's and Spearman's correlation was used to identify risk factors of alveolar bone loss during the intrusion treatment. Results: Deep overbite was successfully corrected (P < 0.05), accompanied by mandibular incisor proclination (P < 0.05). There were no statistically significant change in the true incisor intrusion (P > 0.05). The labial and lingual vertical alveolar bone levels showed a significant decrease (P < 0.05). The alveolar bone is thinning in the labial crestal area and lingual apical area (P < 0.05); accompanied by thickening in the labial apical area (P < 0.05). Proclined incisors, non-extraction treatment, and increased A point-nasion-B point (ANB) degree were positively correlated with alveolar bone loss. Conclusions: While the mandibular intrusion arch effectively corrected the deep overbite, it did cause some unwanted incisor labial tipping/flaring. During the intrusion treatment, the alveolar bone underwent corresponding changes, which was thinning in the labial crestal area and thickening in the labial apical area vice versa. And increased axis change of incisors, non-extraction treatment, and increased ANB were identified as risk factors for alveolar bone loss in patients with mandibular intrusion therapy.