• Advances in concrete construction
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• v.17 no.2
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• pp.111-126
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• 2024

During the clinkering stages of cement production, the chemical composition of fine raw materials such as limestone and clay, which include iron oxide (Fe₂O₃), silicon dioxide (SiO₂) and aluminum oxide (Al₂O₃), significantly influences the quality of the final product. Specifically, the chemical interaction of Fe₂O₃ with CaO, SiO₂ and Al₂O₃ during clinkerisation plays a key role in determining the chemical reactivity and overall quality of the final cement, shaping the properties of the concrete produced. As an extension, this study aims to investigate the physical effects of incorporating nanosized Fe₂O₃ particles as fillers in concrete matrices, and their impact on concrete structures, namely slabs. To accurately model the reinforced concrete (RC) slabs, a refined trigonometric shear deformation theory (RTSDT) is used. Additionally, the stochastic Eshelby's homogenization approach is employed to determine the thermoelastic properties of nano-Fe₂O₃ infused concrete slabs. To ensure comprehensive coverage in the study, the RC slabs undergo various mechanical loads and are exposed to temperature fields to assess their thermo-mechanical performance. Furthermore, the slabs are assumed to rest on a three-parameter viscoelastic foundation, comprising the Winkler elastic springs, Pasternak shear layer and a damping parameter. The equilibrium governing equations of the system are derived using the principle of virtual work and subsequently solved using Navier's technique. The findings indicate that while ferric oxide nanoparticles enhance the mechanical properties of concrete against mechanical loading, they have less favorable effects on its performance against thermal exposure. However, the viscoelastic foundation contributes to mitigating these effects, improving the concrete's overall performance in both scenarios. These results highlight the trade-offs between mechanical and thermal performance when using Fe₂O₃ nanoparticles in concrete and underscore the importance of optimizing nanoparticle content and loading conditions to improve the structural performance of concrete structures.

• Journal of the Korean Regional Science Association
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• v.40 no.3
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• pp.3-21
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• 2024

A safe residential environment enhances the quality of human life and promotes community development through self-actualization. It significantly affects regional stability by influencing the physical and psychological environment necessary to satisfy basic needs, providing a sense of security and alleviating anxiety. Safety is a major housing need; however, current housing policies tend to focus predominantly on housing supply. This emphasis limits the fulfillment of higher-level needs due to poor housing conditions and housing cost burdens faced by young households. Therefore, this study aims to identify areas affected by the stigma effect by analyzing the discrepancy between perceived crime risk and actual crime occurrence among single-person young households. The study compares these stigmatized areas with regions where the perceived crime risk is lower than the actual crime occurrence to identify differences in housing needs satisfaction and to prioritize policy interventions. Additionally, the study examines differences in housing needs satisfaction and importance based on gender to inform policy priorities. By considering the stigma effect on regional housing needs and gender-specific deficiencies, this study provides significant policy implications.

• Journal of the Korean Regional Science Association
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• v.40 no.3
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• pp.109-126
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• 2024

The central government has been promoting innovation cities since the early 2000s for the balanced development of the country in order to solve the problems of overcrowding in the metropolitan area and underdevelopment of the country due to rapid urbanization since the 1980s. The 10 innovation cities built through the regional relocation of public institutions were expected to have positive effects such as economic revitalization and population influx, but uncertainties and various externalities still exist. Therefore, this study aims to analyze innovation cities from the perspective of urban resilience to create sustainable cities. To this end, the research analyzed urban factors in the physical, natural, social, economic, and institutional dimensions of Ulsan Ujeong Innovation City, and applied the Adaptive Cycle and Panarchy to comprehensively analyze them. As a result of the analysis, it was found that the built, socio-economic, and natural environments are currently undergoing the adaptive cycle stages of preservation, reorganization, and growth, respectively, and the interaction and structural causal relationships between Korea, Ulsan Metropolitan City, and Ulsan Ujeong Innovation City were identified. The study concluded that Ulsan Ujeong Innovation City can be sustainable by utilizing opportunities such as the central government's Innovation City Season 2 and financial support, construction of Janghyeon Advanced Industrial Complex, and fostering local innovation clusters according to local conditions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.3
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• pp.281-289
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• 2024

In this study, CO₂-immobilized desulfurized gypsum(CFDG) was applied to ground granulated blast furnace slag to examine the basic properties of mortar and concrete, and to evaluate its responsiveness through field demonstration test. CFDG had a relatively circular composition compared to desulfurized gypsum(DG), and its main components were CaO 47.6 % and SO₃ 22.1 %. As a result of mortar and concrete tests, the flow tended to increase and the compressive strength was at the same level. In addition, the target properties of concrete for application to farm roads, which were a slump of 120±25 mm and a compressive strength of 24 MPa, were satisfied with a slump of 135 mm and a compressive strength of 42.1 MPa at 28 days. In February 2024, an on-site demonstration of a farm road was conducted in Seongmun-myeon, Dangjin-si, and as a result of reviewing the compressive strength according to curing conditions, the physical properties and durability of unhardened concrete, the target results were satisfied, expanding the use of CFDG by applying fine powder of blast furnace slag and carbon reduction can be expected.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.283-289
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• 1986

To establish a suitability grouping system of paddy soils for multiple cropping of rice with other upland crops, the study was carried out after a few basic experiments. In succession to the results on basic experiment prior, the suitability system proposed and the results of application mentioned in this report were summarized as follows; 1. The factors of soil properties in the system were productivities represented by soil texture and drainage class, as well as salinity of surface and sub-soil pH of chemical properties were considered together with slope, warmth index, ground water table, parent materials etc. of soil physical or environmental conditions. The weights of the factors were combined with multiplicatively and additively so as the total marks of ideal soil to be 100. The system was composed with 5 suitability classes; over 91 mark is class I, under 60 mark class V, and each 10 point interval between classes. The limiting factors "P" (in the case that Physical properties or Productivity marks under 24), "S" (Surface slope less than 15) and "C" (Chemical condition below 15) etc. were appended up to two kinds to the classes except a part of soils in class I. 2. The areas where the warmth index exceed 110 in Yeongnam were 19% for class I, 22.7% for class II, 44.7% for class III, 11.5% for class IV, and 2.1% for class V. The rates in class I and II were slightly more than those of the whole country. 3. The points of each soil gained by the system had a positive correlation ($r=.922^{**}$) with the potential productivities.

• Journal of Korean Academy of Nursing
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• v.30 no.6
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• pp.1488-1502
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• 2000

This study, based on current home nursing services, aims at promoting measures for establishing a community-based home nursing system derived from the pilot home nursing demonstration project conducted by the Seoul Nurses Association. The study was based on an analysis of home nursing records from march 1993 to December 1999. The following is a summary analysis, based on individual characteristics of the patients, the organization, which recommended the service for their patients and personnel services. 1. The service has been used by many elderly people 60years of age or older(66.4%). and married people(60.9%). The average number of visits by service personnel for patients of city government was 23.5. This is 2.5 times as many visits by general patients. General patients(20.2%) had only one visit from service personnel, while 65.5% of patients of city government had 10 or more visits. Particularly, for government recommended patients, 72.7% of the patients were recommended by nurses, while only 21.9% where referred to the services by doctors. The main focus of a home nursing service was to maintain present health status (53.4%), and hospice(11.6%). Also to increase hospital-based home nursing services focused on recovery(55.9%) and maintain present health conditions (19.0%). 2. For general patients, 42.0% of patients were suffering from problems related to CVA, 11.3% from high blood pressure, and for patients referred from city, 21.2% from skeletal muscular disease. Results of home nursing services 29.4% of patients were able to recover or maintain their health status, but 48.9% of the patients died. Another main point of community-based home nursing services is medication(6.7%), other basic nursing services(6.1%), special treatment, instructions on how to use medical devices(5.9%), change of physical posture(4.6%), and training on changing physical positions(4.7%). As mentioned above there were some differences between the characteristics of patients who used the pilot home nursing service conducted by the Seoul Nurses Association and those hospital-based service users. The results are believed to be useful to support a community-based home nursing service model. Particularly, patients under medical supervision and patients recommended by government-run health clinics show a higher frequency and longer use of home nursing services compared to general patients or hospital-based home nursing service users. According to the study, nurses accounted for a large number of recommendations for home nursing services. Many patients with CVA, high blood pressure, skeletal muscular disease and bedsores used community-based home nursing services, while others used the service for minor treatments or maintaining their current health status. Based on the study, the researchers make several suggestions to establish a community- based home nursing service system. First, different ways of setting up a community-based home nursing system have to be mapped out based on the evaluation of the pilot home nursing service conducted by the Seoul Nurses Association. Secondly, a new, community-based, home health care nursing service model, and reimbursement payment system have to be developed. This is based on the outcome of the analysis, and implemented policy. Accordingly, efforts are needed to develop a community- based home nursing system with an intermediary role to promote the visiting nursing services of government-run health centers.

• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.4
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• pp.232-246
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• 2018

The purpose of this research is to contribute to clinical researches on neck pain and cervical spondylosis by reviewing the latest research trends and evaluation tools through the analyses of clinical studies on neck pain and cervical spondylosis over the last 5 years. 70 papers satisfying the selection conditions among the RCT papers that had been searched as "neck pain" or "cervical spondylosis" at Pubmed(https://www.ncbi.nlm.nih.gov/pubmed) from March 2011 to February 2016 were targeted. Papers were numbered in order of their publication dates and analyzed by classifying their contents into 1) pain classification, 2) treatment type, 3) treatment duration, 4) treatment time, 5) number of participants, 6) evaluation tools and methods of research, and 7) evaluation duration. 55 papers targeted chronic neck pain, 6 papers acute and subacute neck pain, and 2 papers subacute and chronic neck pain. In comparison by intervention, 43 papers corresponded to physical therapy, 3 papers to acupuncture, 1 to herbal fomentation, 5 to medication, and 18 papers corresponded to multilateral comparisons comparing the efficacy by various interventions. In research period, there were 50 papers based on treatment period, 16 papers based on the number of treatments, and 4 papers based on different periods depending on each group. In treatment duration, the cases from 1 month or more to less than 3 months were most, followed by the cases of less than 1 month, and the cases from 3 months or more to less than 6 months. In treatment frequency, the number of treatments of the treatment group was the same as that of the control group in 51 papers, and many treatments were conducted by the methods of acupuncture, manual therapy, and injection therapy in cases of once or twice of treatments, and physical therapy and electroacupuncture corresponded mainly to the cases from 3 times or more to less than 10 times of treatments, and retrospective observation and exercise programs corresponded mainly to the cases of more than 30 times of treatments. In the number of subjects of the researches, the cases from 50 or more to less than 100 were most, followed by the cases from 20 or more to less than 50. There were 7 evaluation tools cited 10 times or more: VAS, NRS, PPT, NDI, NPQ, CROM, and SF-36. In evaluation period, 37 papers evaluated only during the treatment period, and 33 papers conducted follow-up. In follow-up period, the cases of less than 3 months were most, followed by the cases from 6 months or more to less than 1 year, and the cases from 3 months or more to less than 6 months. When planning clinical researches on cervical pain in the future, appropriate intervention methods, frequency and duration of treatment, period of follow-up, appropriate number of subjects and selection of evaluation tools for objective validity will have to be considered. In addition, randomization, double-blind, etc. will have to be considered for researches with high basis level.

• The korean journal of orthodontics
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• v.33 no.2 s.97
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• pp.121-130
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• 2003

The purpose of this study was to evaluate the possibile clinical application of electroplating to increase diameter of an orthodontic wire, through examining the change of physical properties. The diameter of stainless steel orthodontic wire was increased from 0.016 inch to 0.018 inch by electroplating in a bath of nickel sulfate 100g/L, nickel chloride 60g/L, boric acid 30g/L, and sodium chloride 50g/L, under the conditions of 1.7V, $25\~29^{\circ}C\;and\;3.1\~3.3pH$. During the electroplating, the rate of diameter increase was measured every minute. To investigate uniformity, the diameter was measured at three different locations of each wire specimen aster electroplating. An X-ray diffraction test was performed to analyze the nature of the electroplated metal. Following heat treatment to improve adhesion between the wire and electroplated metal, a three-point bending test was conducted to compare stiffness, field strength, and ultimate strength among four wire groups; 0.016 inch, electroplated 016, electroplated and heat-treated 016, and 0.018 inch wires. Through the comparison of each wire group, following results were obtained. 1. In the load-deflection graph, the curve of the electroplated group was Placed between that of the 0.016 inch group and the 0.018 inch group, and the owe was closer to the 0.018 inch group by heat treatment. 2. In the electroplated and heat-treated 016 wire group, the values of stiffness, yield strength and ultimate strength showed higher tendency than in the original 0.016 Inch group. Stiffness and ultimate strength showed statistically significant differences between two groups. 3. Stiffness, yield strength, and ultimate strength of electroplated wire presented lower values than those of 0.018 inch wire group. 4. Stiffness, yield strength, and ultimate strength of electroplated and heat-treated wire showed higher tendency than those of electroplated wire group, and ultimate strength showed statistically significant difference between two groups. 5. After electroplating, the difference in diameter between the three locations was within $0.1\~0.3\%$ variation, and showed no statistical significance.

• Elastomers and Composites
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• v.46 no.4
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• pp.277-283
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• 2011

In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.

• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.81-85
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• 2007

MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around $400^{\circ}C$, a layer thickness of $700{\AA}$ could be easily obtained with the growth rate of $1.1 {\AA}/s$. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, ${\alpha}=4.143{\pm}0.001{\AA}\;and\;c=6.707{\pm}0.001{\AA}$. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity ($H_c$) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.