• Title/Summary/Keyword: specific migration

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Exploratory Spatial Data Analysis (ESDA) for Age-Specific Migration Characteristics : A Case Study on Daegu Metropolitan City (연령별 인구이동 특성에 대한 탐색적 공간 데이터 분석 (ESDA) : 대구시를 사례로)

  • Kim, Kam-Young
    • Journal of the Korean association of regional geographers
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    • v.16 no.5
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    • pp.590-609
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    • 2010
  • The purpose of the study is to propose and evaluate Exploratory Spatial Data Analysis(ESDA) methods for examining age-specific population migration characteristics. First, population migration pyramid which is a pyramid-shaped graph designed with in-migration, out-migration, and net migration by age (or age group), was developed as a tool exploring age-specific migration propensities and structures. Second, various spatial statistics techniques based on local indicators of spatial association(LISA) such as Local Moran''s $I_i$, Getis-Ord ${G_i}^*$, and AMOEBA were suggested as ways to detect spatial dusters of age-specific net migration rate. These ESDA techniques were applied to age-specific population migration of Daegu Metropolitan City. Application results demonstrated that suggested ESDA methods can effectively detect new information and patterns such as contribution of age-specific migration propensities to population changes in a given region, relationship among different age groups, hot and cold spot of age-specific net migration rate, and similarity between age-specific spatial clusters.

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Migration of Low Molecular Weight Substances from Expanded Polystyrene Cup to Aqueous Food Simulant (발포 폴리스티렌 용기로부터 증류수로의 저분자물질 이행)

  • 이동선;송봉수;최진옥;박우포
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.1056-1062
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    • 2004
  • Migration of low molecular weight components from expanded polystyrene (ESP) to distilled water was measured at different temperature conditions. Overall migration and specific monomer migration were measured. Diffusion model based on Fick's law was used to determine the apparent diffusion coefficients at various experimental conditions. The overall and specific migration levels were estimated to give some practical implications for regulatory guideline development and safe package design. Diffusion coefficients for overall migration in KMnO$_4$ oxidizable extractives and specific migration of styrene monomer from ESP at 6$0^{\circ}C$ were 0.030 and 6.8${\times}$10$^{-5}$ $\textrm{mm}^2$/h, respectively. Their temperature dependence could be explained by Arrhenius equation with respective activation energies of 80.5 and 98.6 kJ/㏖. Experimental conditions ensuring desired migration level were suggested for reliable examination of migration from the packaging material. Some explanatory estimations of migrations were given for some typical conditions of potential usages.

Up and Down Flows of Migration in National-Space Hierarchy Over Time (국토공간계층에서 상방 및 하방 이주 흐름 변화 분석)

  • Han, Yicheol
    • Journal of Korean Society of Rural Planning
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    • v.22 no.1
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    • pp.49-56
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    • 2016
  • Throughout the economic development era of Korea, migration occurred within a spatial hierarchy, with upward flows from rural areas to urban. The concept of step migration is a typical theory to explain these upward migration flows. Recent migration data and trends, however, indicate that migration-pattern regime shows strongly opposite-direction flows, with many of the major migration flowing downward on this national-spatial hierarchy, away from urban areas. In this study, we examine the most recent structure of migration flows up and down within the national-spatial hierarchy. We define seven tiers to tabulate origin-destination migration flows from population density of local administrative districts for the period 2001-2014, and then analyze the migration patterns between the tiers over time. The results show differentiated patterns of migration within the national-spatial hierarchy over time including specific states of migrants' life cycles.

Comparison of the specific migration values from various plastic food packaging materials being used for fatty food and at high temperature obtained by using testing methods as prescribed in the regulations of different country areas (각 국가 권역별 이행 실험방법에 따른 지방성 및 고온가열 식품포장재에서의 특정이행량 비교 조사)

  • Lee, Keun-Taik;Kim, Dong-Joo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.8 no.1
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    • pp.1-10
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    • 2002
  • The actual specific migration data for antioxidants and di-ethylhexyl adipate from plastic food packaging materials being used for fatty food and at high temperature into various food simulants were obtained and compared in accordance with the testing methods and conditions in EU, USA and Korea or Japan. In the case of food packaging material for high temperature use, especially in a thick film such as polypropylene in $450{\mu}m$ thickness, a significant difference in the migration value for antioxidants was observed depending on the migration testing condition and simulants used as defined in the each country areas. Considering the reduction factor of 2 to 5 as being currently applied in EU and USA regulations, the migration values obtained by testing methods of Korea or Japan can exhibit actually higher than those of EU and USA. The migration testing conditions are required to be specified diversely according to the actual exposure temperature of packaging materials.

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A Study on the Metallic ion Migration Phenomena of PCB (PCB의 금속 이온 마이그레이션 현상에 관한 연구)

  • Hong Won Sik;Kang Bo-Chul;Song Byeong Suk;Kim Kwang-Bae
    • Korean Journal of Materials Research
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    • v.15 no.1
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    • pp.54-60
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    • 2005
  • Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. ion migration phenomena has been observed in the field of exposing the specific environment and using for a long tin e. This study was evaluated the generation time of ion migration and was investigated properly test method through water drop test and high temperature high humidity test. Also we observed direct causes and confirmed generation mechanism of dendritic growth as we reproduced the ion migration phenomena. We utilized PCB(printed circuit board) having a comb pattern as follows 0.5, 1.0, 2.0 mm pattern distance. Cu, SnPb and Au were electroplated on the comb pattern. 6.5 V and 15 V were applied in the comb pattern and then we measured the electrical short time causing by ion migration. In these results, we examined a difference of ion migration time depending on pattern materials, applied voltage and pattern spacing of PCB conductor.

Regulations of Food Packaging in Korea, Europe and USA (우리나라, 유럽 및 미국의 식품용 용기포장재 기준규격 관리제도 연구)

  • Jeon, Dae-Hoon;Lee, Young-Ja
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.13 no.2
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    • pp.75-78
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    • 2007
  • Regulation of food packaging in Korea, Eurpoe and USA are surveyed. Food packaging manufacturer or converter has a responsibility to evaluate the safety of migration of harmful materials from typical finished packaging items. The 'overall migration limit' of all components from the packaging and 'specific migration limits(SML)' of monomers or additives are evaluated with food simulants, water, acetic acid, ethanol and n-heptane, based on the regulations of the countries. A substance not regulated has to be authorized with the technical data required, information on chemical identity, physical chemical and other properties, the intended use, migration studies and toxicological studies.

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Design and Implementation of an Object Migration System Using the Java Language (Java 언어를 이용한 객체이동시스템의 설계 및 구현)

  • Jeon, Byeong-Guk;Lee, Geun-Sang;Choe, Yeong-Geun
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.1
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    • pp.49-56
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    • 1999
  • Distributed object Computing, owing to the development of distributed computing, has improved the performance of distributed processing conducted between homogeneous and heterogeneous systems in network. However, it has failed to solve fundamental problems such as network overload and enormous requests demands by servers and clients. In this paper, we propose to design and implement an Object Migration system that uses the java language to tackle the mentioned problems. As the first step of the implementation of the system, we justify the characteristics of t도 mobile object model that keeps codes and states of an object. Implemented Object Migration System would accept objects being migrated to a specific node and support the virtual place in which objects could be executed automatically. Therefore, the Object Migration system we suggest could not only solve problems imposed to traditional distributed computing but also offer transparency of object migration between homogeneous and heterogeneous systems.

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Proactive Virtual Network Function Live Migration using Machine Learning (머신러닝을 이용한 선제적 VNF Live Migration)

  • Jeong, Seyeon;Yoo, Jae-Hyoung;Hong, James Won-Ki
    • KNOM Review
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    • v.24 no.1
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    • pp.1-12
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    • 2021
  • VM (Virtual Machine) live migration is a server virtualization technique for deploying a running VM to another server node while minimizing downtime of a service the VM provides. Currently, in cloud data centers, VM live migration is widely used to apply load balancing on CPU workload and network traffic, to reduce electricity consumption by consolidating active VMs into specific location groups of servers, and to provide uninterrupted service during the maintenance of hardware and software update on servers. It is critical to use VMlive migration as a prevention or mitigation measure for possible failure when its indications are detected or predicted. In this paper, we propose two VNF live migration methods; one for predictive load balancing and the other for a proactive measure in failure. Both need machine learning models that learn periodic monitoring data of resource usage and logs from servers and VMs/VNFs. We apply the second method to a vEPC (Virtual Evolved Pakcet Core) failure scenario to provide a detailed case study.

Migration of Additives from Domestic Plastic Food Contact Materials and Application of Alternative Fatty Food Simulant (국내 합성수지 식품포장재에서의 첨가제 이행과 유지식품용 대체시뮬란트의 응용)

  • 이창성;이근택;이광호
    • Journal of Food Hygiene and Safety
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    • v.12 no.2
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    • pp.132-140
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    • 1997
  • Additives in plastics are capable of migrating from the packaging materials into the foodstuffs, thereby presenting a source of contamination and a potential health risk to the consumer. The migration from packaging materials into foodstuffs is first of all regulated by examining the amounts of global and specific migrated components. Besides, there is worldwide still a need for practical methods for measuring and monitoring migration from polymers, especially for the testing of migration into fatty foodstuffs. Therefore, these studies were undertaken to investigate the safety status of domestic plastic packaging materials with respect to migration. Another objective of this study was to examine the applicability of ethanol as an alternative fatty food simulant substituting for olive oil and n-heptane. The evaporation residues for various dometic plastic samples determined as described in Korean food laws were in the level from 4.3 to 14.5 mg/$\ell$, which were much lower than the limit value of 150 mg/$\ell$. The global migration values into 95 % ethanol showed to be comparable to those into n-heptane, while the olive oil migration values were comparably higher than those into ethanol or n-heptane and moreover they were not reproducible. The kinetic migration begavior of additives in polyolefin samples into 95% ethanol showed a Fickian diffusion process. The results of these studies on global migration and kinetic testings demonstrate that the ethanol could be successfully substitute for the olive oil and n-heptane as an alternative fatty food simulant, at least in contact with polyoefins.

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Comparison of analytical method of headspace and tenax analysis for residue of solvent amounts on plastic packaging materials (Headspace 방법과 tenax 방법을 이용한 잔존 용제 분석 방법의 비교)

  • An, Duek-Jun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.10 no.1
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    • pp.63-68
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    • 2004
  • The regulations for migration amounts in USA, EU and Korea are investigated to compare the actual overall and specific migration date from plastic food packaging materials. Among the packaging materials regulated in above countries, printing ink solvents on packaging materials is used very widely and sometimes cause off-flavor in the food by migration of residual solvents. Even though migration of the residual solvents dose not generally cause safety problems in the contained food, it certainly can generate off-flavor and finally deteriorate quality of the finished product. Therefore regulation and development of analytical method for amount of residual ink solvents are very important issue in food industry. The headspace analytical method and tenax method for residual ink solvent on food packaging materials were evaluated from the accuracy, precise, swiftness and convenience of viewpoint. Headspace analytical method was selected and recommended for using in food industry field.

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