• Title/Summary/Keyword: system composition

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Studies of Nonstoichiometry and Physical Properties of the Perovskite $Sm_{1-x}Sr_xCoO_{3-y}$ System

  • 강진우;류광현;여철현
    • Bulletin of the Korean Chemical Society
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    • v.16 no.7
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    • pp.600-603
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    • 1995
  • A series of samples in the Sm1-xSrxCoO3-y(x=0.00, 0.25, 0.50, 0.75 and 1.00) system has been prepared at 1200 ℃ under ambient atmosphere. The X-ray diffraction patterns of the samples with x=0.00 and 0.25 are indexed with orthorhombic symmetry like GdFeO3 and x=0.50 appears to be perfectly cubic. In the tetragonal system (x=0.75), the structure is similar to that of SrCoO2.80. The composition of x=1.00, SrCoO2.52, shows the brownmillerite-type structure. The reduced lattice volume is increased with x value in this system. The chemical analysis shows the τ value (the amount of the Co4+ ions in the system) is maximized at the composition of x=0.50. Nonstoichiometric chemical formulas are determined by the x, τ and y values. The electrical conductivity has been measured in the temperature range of 78 to 1000 K. The activation energy is minimum for those of x=0.25 and x=0.50 with metallic behavior. First-order semiconductor-to-metal transition of SmCoO3 is not observed. Instead, a broad, high-order semiconductor-to-metal transition is observed. In general, the effective magnetic moment is increased with increasing τ values at low temperature. At high temperature, the magnetic moment is maximum for that of x=0.00. The 3d-electrons are collective and give ferromagnetism in x=0.50.

Fabrication and Evaluation of Powders Containing Calcium Silicate for Solid Self-emulsifying System of Oil (오일 성분의 고형 자가 유화 시스템을 위한 규산칼슘 함유 분말의 제조 및 평가)

  • Sung Giu, Jin
    • Journal of Powder Materials
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    • v.29 no.6
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    • pp.499-504
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    • 2022
  • The objective of this study is to assess the impact of spray drying conditions on medium-chain triglyceride (MCT) loading, solubility, and release of an MCT-loaded solid self-emulsifying system in a water-insoluble oily substance. MCT-loaded solid self-emulsifying systems are prepared by spray drying with SDS and calcium silicate. The effects of inlet temperature (60, 80, or 100℃) and feed solution composition (0, 10, 50, 90, or 100% ethanol) on physicochemical properties of MCT-loaded solid self-emulsifying systems are studied. The inlet temperature significantly affects the water solubility of MCT. Moreover, the feed solution composition significantly affects water solubility, release rate, and MCT loading. The MCT-loaded solid self-emulsifying system obtained at 60℃ using 90% ethanol feed solution shows the best physicochemical properties among the synthesized products and exhibits better water solubility (4.43 ± 0.44 vs. 0 ㎍/mL) and release (94.4 ± 1.6 vs. 32.8 ± 7.4%, 60 min) than a commercial product. Furthermore, the MCT-loaded solid self-emulsifying system shows an excellent emulsion droplet size (approximately 230 nm).

A Study on the Implementation of Mobile Healthcare System using Hybrid App (하이브리드 앱을 이용한 모바일 헬스케어 시스템 구현에 관한 연구)

  • Cho, Yang-Hyun;Kim, Sung Wan;Jeong, Pil-Seong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.503-514
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    • 2013
  • Mobile Healthcare is a new type of health care services for managing health and life irrespective of time and space by uniting IT and BT. For this service bio-signal measurement using WBAN, and data analysis and monitoring technologies based on mobile devices are essential. Generally, however, mobile application has low compatibility because of the features of mobile platform, we have to redevelop it to support the corresponding platform. In this paper we introduce a Mobile Healthcare System which can function as gateway and monitoring based on hybrid app to create ubiquitous healthcare monitoring system compatible with various mobile devices by overcoming the difference of platforms. The proposed system consists of sensor composition part, monitoring composition part, and server composition part.

Improvements in e-Food Exchange of commonly used Foods and search System (ENECC/E-Food Exchange) based on Internet (인터넷 기반의 일상식품의 e-식품교환량(ENECC/E-Food Exchange)과 검색 시스템 개선)

  • Hong, Sun-Myeong;Jo, Hui-Seon;Kim, Gon
    • Journal of the Korean Dietetic Association
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    • v.10 no.2
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    • pp.129-142
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    • 2004
  • The food exchanges are frequently used to nutrition education and counseling for diabetes, weight control, hyperlipidema and etc. But it is difficult to find out food exchange lists with food exchange groups in the food composition table. This study was conducted to select e-food exchange of commonly used foods(456 foods) and improve search system based on internet. Also, the e-food exchange database was developed as having the proximate composition, mineral and vitamin content such as energy, moisture, protein, fat, carbohydrate, ash, calcium, phosphorus, iron, sodium, potassium, retinol equivalent, retinol, a-carotene, thiamin, riboflavin, niacin, ascorbic acid, refuse per 100g of each food. The e-food exchange database developed is basically based on the 6th food composition table(2001) of the National Rural Living Science Institution in Rural Development Administration, Korea. The 456 commonly used foods or 2,262, all foods can be searched easily in a new system. A specific food of e-food exchange can be searched by a given set of food groups or food name and can give information about food one exchange lists, weight and nutrient value per 100g of each food user-friendly on internet. It can be used to make a nutritionally balanced meal plan, nutrition education and counseling.

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A Feature Set Selection Approach Based on Pearson Correlation Coefficient for Real Time Attack Detection (실시간 공격 탐지를 위한 Pearson 상관계수 기반 특징 집합 선택 방법)

  • Kang, Seung-Ho;Jeong, In-Seon;Lim, Hyeong-Seok
    • Convergence Security Journal
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    • v.18 no.5_1
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    • pp.59-66
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    • 2018
  • The performance of a network intrusion detection system using the machine learning method depends heavily on the composition and the size of the feature set. The detection accuracy, such as the detection rate or the false positive rate, of the system relies on the feature composition. And the time it takes to train and detect depends on the size of the feature set. Therefore, in order to enable the system to detect intrusions in real-time, the feature set to beused should have a small size as well as an appropriate composition. In this paper, we show that the size of the feature set can be further reduced without decreasing the detection rate through using Pearson correlation coefficient between features along with the multi-objective genetic algorithm which was used to shorten the size of the feature set in previous work. For the evaluation of the proposed method, the experiments to classify 10 kinds of attacks and benign traffic are performed against NSL_KDD data set.

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Structure and Thermal Properties of a Ternary Al-Cr-Si Quenching Ribbon Manufactured by Single Roll Method (단일 롤 방법으로 제작한 3원계 Al-Cr-Si 급냉리본의 구조 및 열 특성)

  • Han, Chang-Suk;Kim, Ki-Woong;Kim, Woo-Suk
    • Korean Journal of Materials Research
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    • v.31 no.5
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    • pp.296-300
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    • 2021
  • Al-Cr-Si ternary quench ribbons are fabricated using a single roll method and investigated for their structural and thermal properties. In particular, the sinterability is examined by pulse current sintering to obtain the following results. The Al74Cr20Si6 composition becomes a quasicrystalline single phase; by reducing the amount of Cr, it becomes a two-phase mixed structure of Al phase and quasicrystalline phase. As a result of sintering of Al74Cr20Si6, Al77Cr13Si10 and Al90Cr6Si4 compositions, the sintering density is increased with the large amount of Al phase; the sintering density is the highest in Al90Cr6Si4 composition. In addition, as a result of investigating the effects of sintering temperature and pressurization on the sintered density of Al90Cr6Si4, a sintered compact of 99% or more at 513 K and 500 MPa is produced. In particular, since the Al-Cr-Si ternary crystal is more thermally stable than the Al-Cr binary quaternary crystal, it is possible to increase the sintering temperature by about 100 K. Therefore, using an alloy of Al90Cr6Si4 composition, a sintered compact having a sintered density of 99 % or more at 613 K and 250 MPa can be manufactured. It is possible to increase the sintering temperature by using the alloy system as a ternary system. As a result, it is possible to produce a sintered body with higher density than that possible using the binary system, and at half the pressure compared with the conventional Al-Cr binary system.

The Awareness and Demand of Teacher-Librarian for the Composition of E-book Collection: Based on Analysis of the E-books Provided by Busan Digital Library System (전자책 장서 구성에 대한 사서교사의 인식과 요구 - 부산 독서교육종합시스템 전자책 분석을 중심으로 -)

  • Hyo-Jeong, Jang;Jin-Gyeong, Jeong;Yong-Jae, Lee
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.4
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    • pp.399-430
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    • 2022
  • The purpose of this study is to identify the problems of the e-book composition provided by the Comprehensive Reading Education Support System and to propose a service improvement plan related to the establishment of e-books in school libraries as educational resources based on practical issues and perceptions experienced by teacher-librarians. As a research method, the composition of the collection of 3,002 e-books supported by the Busan Comprehensive Reading Education Support System as a reading education platform of the school library was analyzed based on the Korean Decimal Classification. Based on this, two focus group interviews (FGI) were conducted with 4 elementary teacher-librarians and 5 secondary teacher-librarians working in Busan. The result of this study can be used as basic data to support students' reading activities using e-books as educational resources and to form an efficient e-book collection in school library.

A Study on the Characteristics of expression and formal principle of universalism it Architectural Composition (건축형태구성에 있어 보편성 원리와 표현특성에 관한 연구)

  • 이승우
    • Korean Institute of Interior Design Journal
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    • no.16
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    • pp.175-181
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    • 1998
  • The purpose of this study was to analyze the characteristics of expression and formal principle of universalism in Architectural Composition. Theorical category is to find universal system with the connection between idea of society and tradition in compositional frame the results were as follows : First it is the pursuit of divine. Through Middle Age and Renaissance universalism of principles in Architectural Composition is appeared a numerical order and human proportion with applying of cosmology. Second it is the pursuit of schema. With the simplicity of formal image it represented to the geometrical form for its clearness. Third it is the pursuit of typology. As to play a role of decisive factor in formal construction type represented the model with abstraction of shape.

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A study on the planning of the composition and the area of the neuroscience center in general hospital (종합병원 뇌신경센터의 공간구성 및 면적계획에 관한 연구)

  • Yun, Wooyong;Chai, Choulgyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.18 no.1
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    • pp.35-43
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    • 2012
  • Diseases of cranial nerves are one of the most difficult illnesses to be treated because of the fact that diseases are hardly detected in early stage. As the nation is becoming an aging society, there is an increasing number of the patient who has diseases of cranial nerves. So a lot of healthcare facilities is in the middle of having a preparation for medical center providing adequate medical service to the patient suffering from diseases of cranial nerves. However, it is extremely difficult to define what the specialized medical center is. It is necessary to give an architectural suggestion of the specialized medical center in response to the proposal of healthcare system for successful operation. Therefore this study aims to suggest the composition and the area of the medical center on neuroscience.

A Study on the Space Composition and Area Planning of the Cardiovascular Center in General Hospital (종합병원 심혈관센터의 공간구성 및 면적계획에 관한 연구)

  • Yun, Wooyoung;Chai, Choulgyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.18 no.4
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    • pp.75-87
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    • 2012
  • Purpose: As the nation is becoming an aging society, there is an increasing number of the patient who has Diseases of cardiovascular disease. So it is necessarily to build a facility which provides specialized health care. Methods: Field surveys to facilities and analysis to the floor plan have been conducted in order to suggest adequate architectural composition to the specialized cardiovascular center and the dimensions of rooms. Results: The result of this study can be summarized into six points which contain guide to how to organize the specialized cardiovascular center. One of the most important things in this study is to suggest the architectural type which provides efficient collaborating system between the outpatient and angiography unit. Implications: It can be said that this paper can be useful research material when the architect tries to plan the specialized cardiovascular center.