• 제목/요약/키워드: Local Minimum

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CMP 결과에 영향을 미치는 열적거동 특성에 관한 연구 (Investigation of Thermal Behavior Characteristic in Chemical Mechanical Polishing Performance)

  • 정영석;김형재;최재영;김구연;정해도
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1283-1287
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    • 2004
  • The design rules are being more strict with requirement of operation speed and development of IC industry. For this reason, required minimum line-width has been narrowed under sub-micron region. As the length of minimum line-width is narrowed, local and global planarization are being prominent. CMP(Chemical-Mechanical Polishing), one of the planarizarion technology, is a process which polishes with the ascent of chemical reaction and relative velocity between pad and wafer without surface defects. CMP is performed with a complex interaction among many factors, how CMP has an interaction with such factors is not evident. Accordingly, the studies on this are still carrying out. Therefore, an examination of the CMP phenomena and an accurate understanding of compositive factors are urgently needed. In this paper, we will consider of the relations between the effects of temperature which influences many factors having an effect on polishing results and the characteristics of CMP in order to understand and estimate the influence of temperature. Then, through the interaction of shown temperature and polishing result, we could expect to boost fundamental understanding on complex CMP phenomena.

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농촌계획 수립에 적합한 공간단위 설정을 위한 공간 단위에 따른 인구 비교 분석 (Analysis of Population Depending on Spatial Unit for Setting Suitable Spatial Unit to Rural Planning)

  • 이지민
    • 농촌계획
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    • 제25권3호
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    • pp.1-9
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    • 2019
  • Population is important as a fundamental element of local industry and economy, and census data is essential to regional planning and policy making. Although there have been many researches on population and regional planning, there are few studies on population considering spatial unit. In this study, the population of three spatial scales were compared in order to establish the spatial unit suitable for the rural planning. The study area is Gangwon, Chungcheong-Nam, Chungcheong-Buk, Jeolla-Nam, Jeolla-Buk, Gyeonsang-Nam, Gyeonsang-Buk and Jeju province. Population were compared using statistical data analysis, GIS visualization, and spatial statistics. The mean, maximum, minimum, and variance of population were calculated and the coefficient of variation according to spatial unit was compared. The mean, maximum, minimum, and variance of population were calculated and the coefficient of variation according to spatial unit was compared. As the results, the census output area unit is difficult to interpret spatial analysis results. Administrative district unit has the limit that includes areas where the population does not live. The grid unit is well suited to the geographical characteristics but has many disadvantages of the grid with small population. Therefore, It is necessary to complement the limits of the Eup and Myeon-dong administrative district through the grid unit data.

Stability and normal zone propagation in YBCO tapes with Cu stabilizer depending on cooling conditions at 77 K

  • Kruglov, S.L.;Polyakov, A.V.;Shutova, D.I.;Topeshkin, D.A.
    • 한국초전도ㆍ저온공학회논문지
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    • 제22권4호
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    • pp.14-19
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    • 2020
  • Here we present the comparative experimental study of the stability of the superconducting state in 4 mm YBCO tapes with copper lamination against local heat disturbances at 77 K. The samples are either directly cooled by immersing a bare YBCO tape into a liquid nitrogen pool or operate in nearly-adiabatic conditions when the tape is covered by a 0.6 mm layer of Kapton insulation. Main quench characteristics, i.e. minimum quench energies (MQEs) and normal zone propagation (NZP) velocities for both samples are measured and compared. Minimum NZP currents are determined by a low ohmic resistor technique eligible for obtaining V - I curves with a negative differential resistance. The region of transport currents satisfying the stationary stability criterion is found for the different cooling conditions. Finally, we use the critical temperature margin as a universal scaling parameter to compare the MQEs obtained in this work for YBCO tapes at 77 K with those taken from literature for low-temperature superconductors in vacuum at 4.2 K, as well as for MgB2 wires cooled with a cryocooler down to 20 K.

SCALED VISUAL CURVATURE AND VISUAL FRENET FRAME FOR SPACE CURVES

  • Jeon, Myungjin
    • 충청수학회지
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    • 제34권1호
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    • pp.37-53
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    • 2021
  • In this paper we define scaled visual curvature and visual Frenet frame that can be visually accepted for discrete space curves. Scaled visual curvature is relatively simple compared to multi-scale visual curvature and easy to control the influence of noise. We adopt scaled minimizing directions of height functions on each neighborhood. Minimizing direction at a point of a curve is a direction that makes the point a local minimum. Minimizing direction can be given by a small noise around the point. To reduce this kind of influence of noise we exmine the direction whether it makes the point minimum in a neighborhood of some size. If this happens we call the direction scaled minimizing direction of C at p ∈ C in a neighborhood Br(p). Normal vector of a space curve is a second derivative of the curve but we characterize the normal vector of a curve by an integration of minimizing directions. Since integration is more robust to noise, we can find more robust definition of discrete normal vector, visual normal vector. On the other hand, the set of minimizing directions span the normal plane in the case of smooth curve. So we can find the tangent vector from minimizing directions. This lead to the definition of visual tangent vector which is orthogonal to the visual normal vector. By the cross product of visual tangent vector and visual normal vector, we can define visual binormal vector and form a Frenet frame. We examine these concepts to some discrete curve with noise and can see that the scaled visual curvature and visual Frenet frame approximate the original geometric invariants.

Fiscal Policy Effectiveness Assessment Based on Cluster Analysis of Regions

  • Martynenko, Valentyna;Kovalenko, Yuliia;Chunytska, Iryna;Paliukh, Oleksandr;Skoryk, Maryna;Plets, Ivan
    • International Journal of Computer Science & Network Security
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    • 제22권7호
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    • pp.75-84
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    • 2022
  • The efficiency of the regional fiscal policy implementation is based on the achievement of target criteria in the formation and distribution of own financial resources of local budgets, reducing their deficit and reducing dependence on transfers. It is also relevant to compare the development of financial autonomy of regions in the course of decentralisation of fiscal relations. The study consists in the cluster analysis of the effectiveness of fiscal policy implementation in the context of 24 regions and the capital city of Kyiv (except for temporarily occupied territories) under conditions of fiscal decentralisation. Clustering of the regions of Ukraine by 18 indicators of fiscal policy implementation efficiency was carried out using Ward's minimum variance method and k-means clustering algorithm. As a result, the regions of Ukraine are grouped into 5 homogeneous clusters. For each cluster measures were developed to increase own revenues and minimize dependence on official transfers to increase the level of financial autonomy of the regions. It has been proved that clustering algorithms are an effective tool in assessing the effectiveness of fiscal policy implementation at the regional level and stimulating further expansion of financial decentralisation of regions.

Time Series Data Cleaning Method Based on Optimized ELM Prediction Constraints

  • Guohui Ding;Yueyi Zhu;Chenyang Li;Jinwei Wang;Ru Wei;Zhaoyu Liu
    • Journal of Information Processing Systems
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    • 제19권2호
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    • pp.149-163
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    • 2023
  • Affected by external factors, errors in time series data collected by sensors are common. Using the traditional method of constraining the speed change rate to clean the errors can get good performance. However, they are only limited to the data of stable changing speed because of fixed constraint rules. Actually, data with uneven changing speed is common in practice. To solve this problem, an online cleaning algorithm for time series data based on dynamic speed change rate constraints is proposed in this paper. Since time series data usually changes periodically, we use the extreme learning machine to learn the law of speed changes from past data and predict the speed ranges that change over time to detect the data. In order to realize online data repair, a dual-window mechanism is proposed to transform the global optimal into the local optimal, and the traditional minimum change principle and median theorem are applied in the selection of the repair strategy. Aiming at the problem that the repair method based on the minimum change principle cannot correct consecutive abnormal points, through quantitative analysis, it is believed that the repair strategy should be the boundary of the repair candidate set. The experimental results obtained on the dataset show that the method proposed in this paper can get a better repair effect.

유비쿼터스도시의 최소 품질 보장을 위한 필수적인 유비쿼터스도시서비스 제안에 관한 연구 (Proposes on Essential Ubiquitous City Service to Guarantee Minimum Quality of Ubiquitous City)

  • 황병주;김병선;이재용
    • 대한공간정보학회지
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    • 제21권1호
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    • pp.53-64
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    • 2013
  • 2000년대 이후, 정부부처별 유비쿼터스도시사업에 의해 유비쿼터스도시 구축을 전국으로 확산해 나가고 있으나, 근래 들어 유비쿼터스도시에 대한 낮은 체감도가 주요 문제로 대두되고 있다. 이를 해결하기 위해 많은 연구와 정책 과제에서 시민체감형 유비쿼터스서비스를 발굴하려는 시도가 이어지고 있지만, 유비쿼터스도시계획을 수립하는 단계에서 이러한 서비스를 효과적으로 접목하기 위한 연구는 부족한 실정이다. 이 연구에서는 유비쿼터스도시 계획 수립단계에서 적용할 수 있는 필수적인 유비쿼터스도시서비스를 도출하여 유비쿼터스도시의 최소 품질을 보장할 수 있는 방안을 제안한다. 이를 위해 먼저, 163개 시 군 지자체를 대상으로 유비쿼터스도시 추진 현황을 조사하여 U-City의 현주소를 진단하였다. 또한 38명의 U-City 관련 전문가를 대상으로 약 한 달 동안 전문가 설문조사를 실시하여 보편성, 지역경제육성, 사회복지구현, 효과적인 도시관리 관점의 필수적인 14개 유비쿼터스도시서비스를 도출하였다. 마지막으로, 11개 지자체의 유비쿼터스도시계획(안)과 도출된 필수 U-City 서비스를 비교하여 시사점을 도출하였다.

Characterization and Comparative Evaluation of Milk Protein Variants from Pakistani Dairy Breeds

  • Yasmin, Iqra;Iqbal, Rabia;Liaqat, Atif;Khan, Wahab Ali;Nadeem, Muhamad;Iqbal, Aamir;Chughtai, Muhammad Farhan Jahangir;Rehman, Syed Junaid Ur;Tehseen, Saima;Mehmood, Tariq;Ahsan, Samreen;Tanweer, Saira;Naz, Saima;Khaliq, Adnan
    • 한국축산식품학회지
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    • 제40권5호
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    • pp.689-698
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    • 2020
  • The aim of study was to scrutinize the physicochemical and protein profile of milk obtained from local Pakistani breeds of milch animals such as Nilli-Ravi buffalo, Sahiwal cow, Kajli sheep, Beetal goat and Brela camel. Physicochemical analysis unveiled maximum number of total solids and protein found in sheep and minimum in camel. Buffalo milk contains the highest level of fat (7.45%) while camel milk contains minimum (1.94%). Ash was found maximum in buffalo (0.81%) and sheep (0.80%) while minimum in cow's milk (0.71%). Casein and whey proteins were separated by subjecting milk to isoelectric pH and then analyzed through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed heterogeneity among these species. Different fractions including αS1, αS2, κ-casein, β-casein and β-lactoglobulen (β-Lg) were identified and quantitatively compared in all milk samples. Additionally, this electrophoretic method after examining the number and strength of different protein bands (αS1, αS2, β-CN, α-LAC, BSA, and β-Lg, etc.), was helpful to understand the properties of milk for different processing purposes and could be successfully applied in dairy industry. Results revealed that camel milk was best suitable for producing allergen free milk protein products. Furthermore, based on the variability of milk proteins, it is suggested to clarify the phylogenetic relationships between different cattle breeds and to gather the necessary data to preserve the genetic fund and biodiversity of the local breeds. Thus, the study of milk protein from different breed and species has a wide range of scope in producing diverse protein based dairy products like cheese.

한국의 주요 대도시에 대한 일 최고 및 최저 기온의 장기변동 경향과 건강에 미치는 영향 전망 (Long-term Trends of Daily Maximum and Minimum Temperatures for the Major Cities of South Korea and their Implications on Human Health)

  • 최병철;김지영;이대근
    • 대기
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    • 제17권2호
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    • pp.171-183
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    • 2007
  • Trends of daily maximum and minimum temperatures in major cities of South Korea (Seoul, Busan, Incheon, Daegu, and Ulsan) during the past 40 years (1961-2000) were investigated. Temperature records for the Chupungryeong station were compared with those of the large cities because of the rural environment of the station. There were distinct warming trends at all stations, although the warming rates depend on each station's local climate and environment. The warming rates in Korea are much greater than the global warming trends, by a factor of 3 to 4. The most increasing rate in daily maximum temperature was at Busan with $0.43^{\circ}C$ per decade, the most increasing rate in daily minimum temperature was at Daegu with $0.44^{\circ}C$ per decade. In general, the warming trends of the cities were most pronounced in winter season with an increasing rate of $0.5^{\circ}C$/decade at least. Diurnal temperature range shows positive or negative trends according to the regional climate and environmental change. The frequency distribution of the daily temperatures for the past 40 years at Seoul and Chupungryeong shows that there have been reductions in cold day frequencies at both stations. The results imply that the impacts on human health might be positive in winter and adverse in summer if the regional warming scenario by the current regional climate model reflects future climate change in Korea.

광 버스트 스위칭 망에서 최소 경로비용 기반의 동적 경로배정 기법 (Dynamic Routing Algorithm based on Minimum Path-Cost in Optical Burst Switching Networks)

  • 이해정;송규엽;유경민;유완;김영천
    • 한국통신학회논문지
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    • 제30권3B호
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    • pp.72-84
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    • 2005
  • 광 버스트 스위칭 방식은 제어 채널과 데이터 채널을 분리하여 버스트 제어 패킷을 제어 채널로 먼저 전송하고 Offset 시간 후에 도착할 데이터 버스트에 대한 데이터 채널을 예약하는 단방향 예약 특성을 가지고 있다. 그러나 이러한 특성 때문에 버스트 간에 데이터 채널을 예약하기 위한 경합이 발생하게 되며 경합에 실패한 버스트는 손실되어 심각한 QoS (Quality of Service) 저하를 초래한다. 따라서 본 논문에서는 버스트 손실을 최소화하기 위해 노드에서 발생되는 버스트 손실이 임계값을 초과할 경우 버스트 우선순위와 버스트가 생성된 근원지 정보에 따라 유동적으로 경로를 재설정하는 동적 경로 설정 기법을 제안하였다. 이와 같이 제안된 기법은 기존 경로로 전송되고 있는 버스트 흐름에 영향을 최소화하기 위하여 링크 비용을 고려한 최소 경로 비용을 기반으로 하고 있다. 또한, 제안된 기법의 성능 평가를 위하여 버스트 손실률, 버스트 처리율 및 평균 흡수 관점에서 기존의 기법과 비교 평가하였다.