• Title/Summary/Keyword: Local Minimum

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

  • Jeong, Young-Seok;Kim, Hyoung-Jae;Choi, Jae-Young;Kim, Goo-Youn;Jeong, Hae-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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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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Analysis of Population Depending on Spatial Unit for Setting Suitable Spatial Unit to Rural Planning (농촌계획 수립에 적합한 공간단위 설정을 위한 공간 단위에 따른 인구 비교 분석)

  • Lee, Jimin
    • Journal of Korean Society of Rural Planning
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    • v.25 no.3
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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.
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.4
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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
    • Journal of the Chungcheong Mathematical Society
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    • v.34 no.1
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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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    • v.22 no.7
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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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    • v.19 no.2
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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.

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

  • Hwang, Byung Ju;Kim, Byeong Sun;Lee, Jae Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.53-64
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    • 2013
  • Since 2000, ubiquitous cities are spread over Korea by government's supporting project for ubiquitous city construction. But recently problems such as low perception of ubiquitous city are issued. There is just a few studies about a creation of citizen centric ubiquitous city service even though there have been several studies and policies to overcome such problems. There is not enough research on applying ubiquitous city service effectively at the stage of ubiquitous city plan. To solve this problems, this study ultimately aims to suggest essential ubiquitous city service applied at that stage to guarantee minimum quality of ubiquitous city. The expert survey method was employed to select essential ubiquitous city service. To achieve this goal, First, a survey performed by 163 local government officers to know current status of the ubiquitous city construction project. Second, another survey was performed for about 30 days by 38 experts worked at local public official and ubiquitous city organization to select essential ubiquitous city service. Finally we suggested 14 essential ubiquitous city service from the several viewpoints, which were universality, industry growth, social welfare, effective city management. And we analyzed the differences between ubiquitous city services written 14 ubiquitous city plan and essential ubiquitous city services.

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
    • Food Science of Animal Resources
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    • v.40 no.5
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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.

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

  • Choi, Byoung-Cheol;Kim, Jiyoung;Lee, Dae-Geun;Kysely, Jan
    • Atmosphere
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    • v.17 no.2
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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.

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

  • Lee Hae joung;Song Kyu yeop;Yoo Kyoung min;Yoo Wan;Kim Young chon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.3B
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    • pp.72-84
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    • 2005
  • Optical burst switching networks usually employ one-way reservation by sending a burst control packet with a specific offset time, before transmitting each data burst Same. Due to such a Property, burst-contentions occur when multiple bursts contend for the same wavelength in the same output link simultaneously in a node, leading to burst losses, eventually degrading the quality of service. Therefore, in this paper, we propose a dynamic routing algorithm using minimum local state information in order to decrease burst-contentions. In this proposed scheme, if burst loss rate exceeds a threshold value at a certain node, a new alternative routing path is chosen according to burst priority and location of burst generation, which enables the contending bursts to detour around the congested link. Moreover, for reducing the effect of sending bursts on the primary path due to the alternative path, we also apply a minimum path-cost based routing on link-cost concept. Our simulation results show that proposed scheme improves the network performance in terms of burst loss probability and throughput by comparing with conventional one.