• 유통과학연구
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• 제17권3호
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• pp.21-30
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• 2019

Purpose - While many related prior studies have focused on the segregation by race and ethnicity, the academic interest in the separation of residence by income and social class is gradually increasing. This study aims to not only investigate spatial pattern of economic segregation and poverty rate in South Korea, but also shed light on what affect residential distribution of the poor. Research design, data, and methodology - The unit of analysis is Si-Gun-Gu municipal level entities of South Korea. Most demographic, socioeconomic, and residential variables were derived from Korean Census Data in 2015. In order to examine spatial patterns of economic segregation and poverty rate in South Korea, a series of measurements and visualization was conducted through the Geo-Segregation Analyzer and ArcGIS programs. Determinants of economic segregation and local poverty rates were investigated by regression analyses using STATA. Results - The spatial patterns of areas with high poverty rates were extremely clustered, while the distribution of areas with high economic segregation was relatively evenly distributed. Demographic, residential, and local factors appeared to affect whether the poor live in particular area or spread evenly. Conclusions - The factors that raise the poverty rate result in lower level of economic segregation, while factors that reduce the poverty rate lead to severe level of economic segregation.

• 한국지역지리학회지
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• 제13권5호
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• pp.477-494
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• 2007

본 논문은 부산시를 대상으로 1900년대 초(구한말)부터 현재에 이르기까지 거주지역의 불평등한 현상을 거주분화의 개념을 중심으로 사회공간적으로 분석한다. 부산은 1900년대 초 조선 전통사회의 성격을 이어받아 신분사회의 계층질서에 의한 거주선택의 제한으로 불평등한 거주공간이 형성되었다. 이후 일제에 의한 신시가지의 형성으로 기존의 한국인 거주지와 분리되는 현상을 경험하였으며 일본인과 한국인, 그리고 중국인 거주지역으로 구분되는 민족별 분화 현상도 나타났다. 해방과 한국전쟁 이후 급속하게 인구가 증가함으로써 새로운 빈민거주지역이 등장하였고 이는 이후에 전개될 거주지 분화의 주요 요인으로 작용하게 된다. 빈민지역의 문제를 해소하기 위해 1960년대부터 실시한 정책이주는 제도상의 결점으로 인하여 큰 효과를 보지 못하였다. 1990년 이후 주민의 사회경제적 지위는 주택선택에 영향을 주어 주택계층에 의한 거주지역분화를 가능하게 하였다. 중간주택계층보다는 상 하위 주택계층이 거주공간의 불평등한 분포에 큰 영향을 주었다. 맥락적이고 시계열적인 접근방법을 시도하여 거주공간의 사회공간적 불평등에 관한 인과성을 파악하려고 시도한 본 연구는 미래에 전개될 거주공간패턴을 예측하고 다른 도시들의 거주공간연구에 도움을 줄 것으로 예상된다.

• 열병합발전
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• 통권30호
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• pp.21-25
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• 2002

According to recent Korea Electric Power Company report, yearly distribution line brass cramp bolts failure summed up to 4,400 cases emerging as one of main local break-down causes. Naturally, the need for the investigation was proposed To determine the root cause of the cramp bolt failures, mechanical and metallurgical investigation were performed for 90 samples which collected from various sites. For the understanding of the geometric characteristics, stress distribution was evaluated by CAE program and proof load of each bolts was tested. The SEM&EDS was used for metallurgical investigation. Through the investigation, the root causes of failures were confirmed. All damaged bolts showed intergrannular fracture mode and the all fractured bolt showed ß phase morphology contrast to the a&ß mixture morphology of the non-damaged samples. Additionally, EDS analysis confirmed the existence of lead rich layer on grain boundaries.

• 소성∙가공
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• 제33권1호
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• pp.12-17
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• 2024

Aluminum-zinc-magnesium alloy is a well-known alloy that is both strong and lightweight. Precipitation strengthening plays a significant role in the strength mechanism of this alloy, with nano-sized η-based precipitates being the representative precipitates. However, the growth of η precipitates can lead to a decrease in strength, necessitating research into ways to control their growth. In this study, we observed the atomic-level behavior of η₂ precipitates and discovered that the precipitates grew through a combination with magnesium after a zinc segregation layer was formed around them.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3669-3676
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• 2013

Faithful transmission of genetic information depends on accurate chromosome segregation as cells exit from mitosis, and errors in chromosomal segregation are catastrophic and may lead to aneuploidy which is the hallmark of cancer. In eukaryotes, an elaborate molecular control system ensures proper orchestration of events at mitotic exit. Phosphorylation of specific tyrosyl residues is a major control mechanism for cellular proliferation and the activities of protein tyrosine kinases and phosphatases must be integrated. Although mitotic kinases are well characterized, phosphatases involved in mitosis remain largely elusive. Here we identify a novel variant of mouse protein tyrosine phosphatase containing domain 1 (Ptpcd1), that we named Ptpcd2. Ptpcd1 is a Cdc14 related centrosomal phosphatase. Our newly identified Ptpcd2 shared a significant homology to yeast Cdc14p (34.1%) and other Cdc14 family of phosphatases. By subcellular fractionation Ptpcd2 was found to be enriched in the cytoplasm and nuclear pellets with catalytic phosphatase activity. By means of immunofluorescence, Ptpcd2 was spatiotemporally regulated in a cell cycle dependent manner with cytoplasmic abundance during mitosis, followed by nuclear localization during interphase. Overexpression of Ptpcd2 induced mitotic exit with decreased levels of some mitotic markers. Moreover, Ptpcd2 failed to colocalize with the centrosomal marker ${\gamma}$-tubulin, suggesting it as a non-centrosomal protein. Taken together, Ptpcd2 phosphatase appears a non-centrosomal variant of Ptpcd1 with probable mitotic functions. The identification of this new phosphatase suggests the existence of an interacting phosphatase network that controls mammalian mitosis and provides new drug targets for anticancer modalities.

• 분석과학
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• 제5권2호
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• pp.191-197
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• 1992

익산군(益山郡) 용제리(龍提里)에서 출토(出土)된 기원전(紀元前)의 세형동검(細形銅劍)을 습식(濕式) 및 원자흡수분광법(原子吸收分光法)으로 조성(組成)을 정량(定量)하였으며, 시편(試片)을 연마(硏磨), 부식(腐蝕)시켜 광학현미경(光學顯微鏡)과 주사형(走査型) 전자현미경(電子顯微鏡)으로 미세구조(微細構造)를 관찰(觀察)하였다. 또한 질량분석계(質量分析計)를 써서 납동위원소비(同位元素比)를 측정(測定)하여 원료(原料)의 산지(産地)를 추정(推定)코자 하였다. 세형동검(細形銅劍)은 Cu-Sn-Pb계(系)로서 Sn이 17%, Pb가 6.8%로서 Sn이 10% 이상이고 Pb가 첨가(添加)된 것으로 보아 청동기(靑銅器) 중기(中期) 이후(以後)임을 알 수 있었다. 시료내부(試料內部)는 ${\alpha}$와 (${\alpha}+{\delta}$) 공정(共晶)으로 되어 있으며 편석(偏析)이 일어나 있었다. 원료(原料)는 중국(中國) 북부산(北部産)일 가능성(可能性)이 크다.

• Computers and Concrete
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• 제19권5호
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• pp.555-566
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• 2017

Recently some efforts have been performed to combine the advantages of light-weight and self-compacting concrete in one package called Light-Weight Self-Compacting Concrete (LWSCC). Accurate prediction of hardened properties from fresh state characteristics is vital in design of concrete structures. Considering the lack of references in mixture design of LWSCC, investigating the proper mixture components and their effects on mechanical properties of LWSCC can lead to a reliable basis for its application in construction industry. This study utilizes wide range of existing data of LWSCC mixtures to study the individual and combined effects of the components on the compressive strength. From sensitivity of compressive strength to the proportions and interaction of the components, two equations are proposed to estimate the LWSCC compressive strength. Predicted values of the equations are in good agreement with the experimental data. Application of lightweight aggregate to reduce the density of LWSCC may bring some mixing problems like segregation. Reaching a higher strength by lowered density is a challenging problem that is investigated as well. The results show that, the compressive strength can be improved by increasing the of mixture density of LWSCC, especially in the range of density under $2000Kg/m^3$.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.659-663
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• 2001

In Japan, the municipal solid waste, which amounts to 50 million tons, is generated every year and most of it is incinerated. The bottom and fly ashes are disposed to the registered disposal areas under the provisions of The Waste Disposal and Public Cleaning Law. Especially, as the fly ash from the municipal waste incineration (the primary fly ash) contains heavy metals (lead, zinc, etc) and dioxins, it cannot be disposed directly without decontamination, such as moiling, cementation, chelating and dissolving processes provided in the law. However, these procedures for decontamination, except melting, are not enough for dioxins. Even in case of melting, the fly ash from the process (the secondary fly ash) contains high concentration of heavy metals (e.g., Zn; 1-20%, Pb; 1-10%). For these reasons, Metal Mining Agency of Japan (MMAJ), a governmental organization, started a four-year project to develop the treatment technologies of these fly ashes in 1999. The purpose of the project is to establish the integrated technologies to recover the valuable metals from, and to decontaminate, the primary and secondary fly-ashes in the practical scale by utilizing the existing metallurgical processes and facilities, along with the energy saving and the reduction of the environmental impact.

• Plant Resources
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• 제6권2호
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• pp.98-101
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• 2003

Colored apiculus, awn, and long empty glume are indicators of wildness and are usually eliminated during rice domestication. Genetic analysis was conducted to clarify the inheritance patterns of awn, apiculus color, and long empty glume in Korean rice collection. Based on individual characterization of F$_2$ progenies derived from crosses between parents with colorless and purple apiculus, two (3 colored: 1 colorless) or three dominant genes (9 purple: 3 red: 4 colorless) are estimated as controlling this character by simultaneous complementary action. Different inheritance systems were detected between S237 and S245 of 'Shareibyeo' which belong to the weedy type. To determine the genes responsible in awning and long empty glume characters, the inheritance of landrace varieties of rice ('Naengdo' and 'Yuna') was investigated. In the crosses of awned land race and awnless cultivar, three dominant genes are supposed to control the awning genetic system by 63 awned: 1 awnless individual. As for long empty glume, one recessive gene, g-l on the chromosome 4, was the one controlling the segregation ratio of 3 normal empty: 1 long empty glume. By analyzing the Korean rice collection, the inheritance systems of these wild characters may lead to a better understanding of rice domestication in the future.

• Advances in concrete construction
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• 제5권6호
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• pp.587-611
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• 2017

This study focused on the influences regarding the use of polyepoxide-based polymer and silica fume (SF) on the fresh and hardened state properties of self-compacting lightweight concrete (SCLC) along with their impacts on electrical resistance and ultrasonic pulse velocity (UPV). To do so, two series of compositions each of which consists of twelve mixes, with water to binder (W/B) ratios of 0.35 and 0.4 were cast. Three different silica fume/binder ratios of 0, 5%, and 10% were considered along with four different polymer/binder ratios of 0, 5%, 10%, and 15%. Afterwards, the rupture modulus, tensile strength, 14-day, 28-day, and 90-day compressive strength, the UPV and the electrical resistance of the mixes were tested. The results indicated that although the use of polymer could enhance the passing and filling abilities, it could lead to a decrease of segregation resistance. In addition, the interaction of the SF and the polymeric contents enhanced the workability. However, the impacts regarding the use of polymeric contents on fresh state properties of SCLC were more prevalent than those regarding the use of SF. Besides the fresh state properties, the durability and mechanical properties of the mixes were affected due to the use of polymeric and SF contents. In other words, the use of the SF and the polymer enhanced the durability and mechanical properties of SCLC specimens.