• Title/Summary/Keyword: Design class

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Study on Developing Assessment Guideline for Safety and Performance of Electric Moxibustion Apparatus (전기식 온구기에 대한 안전성 및 성능 평가 가이드라인 개발 연구)

  • Yi, Seung-Ho;Kang, Jung-Won;Nam, Dong-Woo;Kim, Eun-Jung;Lee, Hye-Jung;Kim, Kap-Sung;Lee, Jae-Dong
    • Journal of Acupuncture Research
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    • v.27 no.1
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    • pp.75-86
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    • 2010
  • Objectives : We developed and proposed a guideline for safety and performance assessment of electric moxibustion apparatus (class II medical device). Methods : We drafted the guideline for safety and performance assessment of electric moxibustion apparatus by referring the existing standards, guidelines and measurement data from commercially available products. Temperature characteristics such as maximum temperature and ramp time, and physical characteristics such as weight, noise and diameter were measured. User friendliness was also evaluated for commercial devices. Results : This guideline only can be applied to the electric moxibustion apparatus where moxa is being heated by electricity for medical proposes. Maximum temperature of higher than $50^{\circ}C$ can be achieved mostly. Ramp rate of temperature seems to be reliable. Control of temperature is needed to be improved. Moxa and its derivative products seem to be regulated for reliable temperature performance for clinical application. Requirements for design and development of electric moxibustion apparatus are suggested : temperature indicator, temperature control and its accuracy, safety measure, surge protection, user friendliness and instruction for use (IFU). Design recommendation of the reduction of noise level and energy loss are suggested for better products. Conclusions : We proposed a guideline for safety and performance assessment of electric moxibustion apparatus to improve the quality of relating products and aid their commercialization by aiming higher industrial competitiveness of the medical device sectors in Korea. Discussion with related institutes such as industry, academy and government is further required. Public hearings also need to be held prior to the establishment of a final guideline and standard.

Step-down Piezoelectric Transformer Using PZT PMNS Ceramics

  • Lim Kee-Joe;Park Seong-Hee;Kwon Oh-Deok;Kang Seong-Hwa
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.3
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    • pp.102-110
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    • 2005
  • Piezoelectric transformers(PT) are expected to be small, thin and highly efficient, and which are attractive as a transformer with high power density for step down voltage. For these reasons, we have attempted to develop a step-down PT for the miniaturized adaptor. We propose a PT, operating in thickness extensional vibration mode for step-down voltage. This PT consists of a multi-layered construction in the thickness direction. In order to develop the step-down PT of 10 W class and turn ratio of 0.1 with high efficiency and miniaturization, the piezoelectric ceramics and PT designs are estimated with a variety of characteristics. The basic composition of piezoelectric ceramics consists of ternary yPb(Zr$_{x}$Ti$_{1-x}$)O$_{3}$-(1-y)Pb(Mn$_{1/3}$Nb1$_{1/3}$Sb$_{1/3}$)O$_{3}$. In the piezoelectric characteristics evaluations, at y=0.95 and x=0.505, the electromechanical coupling factor(K$_{p}$) is 58$\%$, piezoelectric strain constant(d$_{33}$) is 270 pC/N, mechanical quality factor(Qr$_{m}$) is 1520, permittivity($\varepsilon$/ 0) is 1500, and Curie temperature is 350 $^{\circ}C$. At y = 0.90 and x = 0.500, kp is 56$\%$, d33 is 250 pC/N, Q$_{m}$ is 1820, $\varepsilon$$_{33}$$^{T}$/$\varepsilon$$_{0}$ is 1120, and Curie temperature is 290 $^{\circ}C$. It shows the excellent properties at morphotropic phase boundary regions. PZT-PMNS ceramic may be available for high power piezoelectric devices such as PTs. The design of step-down PTs for adaptor proposes a multi-layer structure to overcome some structural defects of conventional PTs. In order to design PTs and analyze their performances, the finite element analysis and equivalent circuit analysis method are applied. The maximum peak of gain G as a first mode for thickness extensional vibration occurs near 0.85 MHz at load resistance of 10 .The peak of second mode at 1.7 MHz is 0.12 and the efficiency is 92$\%$.

Seismic structural demands and inelastic deformation ratios: Sensitivity analysis and simplified models

  • Chikh, Benazouz;Laouami, Nacer;Mebarki, Ahmed;Leblouba, Moussa;Mehani, Youcef;Kibboua, Abderrahmane;Hadid, Mohamed;Benouar, Djillali
    • Earthquakes and Structures
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    • v.13 no.1
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    • pp.59-66
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    • 2017
  • Modern seismic codes rely on performance-based seismic design methodology which requires that the structures withstand inelastic deformation. Many studies have focused on the inelastic deformation ratio evaluation (ratio between the inelastic and elastic maximum lateral displacement demands) for various inelastic spectra. This paper investigates the inelastic response spectra through the ductility demand ${\mu}$, the yield strength reduction factor $R_y$, and the inelastic deformation ratio. They depend on the vibration period T, the post-to-preyield stiffness ratio ${\alpha}$, the peak ground acceleration (PGA), and the normalized yield strength coefficient ${\eta}$ (ratio of yield strength coefficient divided by the PGA). A new inelastic deformation ratio $C_{\eta}$ is defined; it is related to the capacity curve (pushover curve) through the coefficient (${\eta}$) and the ratio (${\alpha}$) that are used as control parameters. A set of 140 real ground motions is selected. The structures are bilinear inelastic single degree of freedom systems (SDOF). The sensitivity of the resulting inelastic deformation ratio mean values is discussed for different levels of normalized yield strength coefficient. The influence of vibration period T, post-to-preyield stiffness ratio ${\alpha}$, normalized yield strength coefficient ${\eta}$, earthquake magnitude, ruptures distance (i.e., to fault rupture) and site conditions is also investigated. A regression analysis leads to simplified expressions of this inelastic deformation ratio. These simplified equations estimate the inelastic deformation ratio for structures, which is a key parameter for design or evaluation. The results show that, for a given level of normalized yield strength coefficient, these inelastic displacement ratios become non sensitive to none of the rupture distance, the earthquake magnitude or the site class. Furthermore, they show that the post-to-preyield stiffness has a negligible effect on the inelastic deformation ratio if the normalized yield strength coefficient is greater than unity.

Trends of fashion journalism - An analysis under fashion article in magazines of korea - (우리나라 잡지의 패션기사를 통해 패션저널리즘의 동향)

  • 김영숙
    • Archives of design research
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    • no.16
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    • pp.161-170
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    • 1996
  • In an attempt to teace trands in fashion journalism based on the examination of recent fashion magazines in korea, this study has dealt with the followings: the number of articles on fashion, image of fashion, characteristics of articles, change in "coordinate" and titles, and length of time of publication. The results of this study follow: 1. Among the general magazines for ladies whose titles have been changed, those dedicated to the "Ms class" have increased the pages on fashion and coverage of casual brand: those for housewives have shown no change in contents despite the change in titles, 2. The length of time of publication does not affect the change in the number of articles on fashion. General magazines for ladies have shown the greater "coordinate" in articles on fashion. 3. In terms of the contents of articles on fashion, those devoted to fashion and clothing are specialized and innovation-oriented, whereas general magaines stress the provision of more practical information. 4. The emergence of the X-generation and the newer generation has resulted in positioning of clothing crand, making them chief tarhet readers.ing them chief tarhet readers.

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A study on the development of hospital rounds information system utilizing NFC (NFC를 활용한 병원 회진 안내 시스템 개발에 관한 연구)

  • Lee, Hyo Seung;Oh, Jae Chul
    • Smart Media Journal
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    • v.5 no.3
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    • pp.67-73
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    • 2016
  • Now, Korean health technology and health service is proud to be world class one at a level of not falling behind anywhere in the world. However, this health service has been provided, centering on hospital or medical staff, not patient so far. And there is a tendency to gradually change into patient-centered health service. According to the results of survey performed by Korea Institute for Health and Social Affairs, it was reported that, as of 2016, 30% or more of inpatients were not sufficiently given information relating to hospital rounds, and in particular, 50% or more of inpatients in their twenties to thirties expressed discontent, and approximately 17% of inpatients in their seventies and beyond expressed discontent. In the light of these data, especially inpatients in their twenties to thirties want information relating to hospital rounds and the like. And taking into consideration that they are characterized by being accustomed to using a smartphone, it is intended to design and implement a hospital rounds information smartphone application. Now, in some of medium and large hospitals, information about hospital is provided through smartphone application. However, the main purpose is hospital information or outpatient's appointment to see a doctor and so on. Even in case of providing information about hospital rounds, only information about approximate time to make rounds is provided. This paper is intended to design and implement hospital rounds information system making it possible to check their turn when rounds are made by utilizing NFC function in smart phone.

College students' experience and intention to purchase organic clothes according to their lifestyle characteristics (라이프스타일 특성에 따른 오가닉 의류제품 구매경험과 구매의도)

  • Park, Hea-Ryung;Park, Mi-ryung;Cho, Shin-hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3087-3098
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    • 2015
  • This study aims to examine the college students experience and intention to purchase organic clothes according to their lifestyle as the most promising consumer class in future. First, it was found that their experience to purchase organic clothes according to the subjects demographic characteristics showed significant differences in the categories of gender, age, related major, pocket money and income from except their residential areas. Second, factor structure analysis of their lifestyles was conducted and the factors analyzed were divided into "well-being orientation", "pursuit of changes", "eco-friendly view", "trend innovation", and "conservative security". Third, the present study examined differences in sub-dimensions of lifestyle characteristics such as "well-being orientation", "pursuit of changes", "eco-friendly view", "trend innovation", and "conservative security" depending on their experience or non-experience to purchase organic clothes and found that "well-being orientation", "pursuit of changes", "eco-friendly view", and "trend innovation" were higher in the group with experience to purchase organic clothes than in that with non-experience and it was known that all sub-factor groups including "well-being orientation", "pursuit of changes", "eco-friendly view", "trend innovation", and "conservative security" had a significant influence on intnetion to purchase organic clothes.

Influence on Predicted Performance of Jointed Concrete Pavement with Variations in Axle Load Spectra (축하중 분포 변화가 콘크리트 포장의 공용성 예측결과에 미치는 영향 연구)

  • Lee, Kyungbae;Kwon, Soonmin;Lee, Jaehoon;Sohn, Duecksu
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.11-19
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    • 2014
  • PURPOSES : The purpose of this article is to investigate the predicted life of jointed concrete pavement (JCP) with two variables effecting on axle load spectra (ALS). The first variable is different data acquisition methods whether using high-speed weigh-in-motion (HS-WIM) or not and the other one is spectra distribution due to overweight enforcement on main-lane of expressway using HS-WIM. METHODS : Three sets of ALS had been collected i) ALS provided by Korea Pavement Research Program (KPRP), which had been obtained without using HS-WIM ii) ALS collected by HS-WIM before the enforcement at Kimcheon and Seonsan site iii) ALS collected after the enforcement at the same sites. And all ALS had been classified into twelve vehicle classes and four axle types to compare each other. Among the vehicle classes, class 6, 7, 10 and 12 were selected as the major target for comparing each ALS because these were considered as the primary trucks with a high rate of overweight loading. In order to analyze the performance of JCP based on pavement life, fatigue crack and International Roughness Index (IRI) were predicted using road pavement design program developed by KPRP and each ALS with same annual average daily traffic (AADT) was applied to design slab thickness. RESULTS : Comparison ALS of KPRP with those of HS-WIM shows that the ALS of KPRP has a low percentage of heavy spectra such as 6~9 tonnes for single axle, 18~21 tonnes for tandem axle and 27~30 tonnes for tridem axle than other two ALS of HS-WIM in most vehicle classes and axle types. It means that ALS of KPRP was underestimated. And after the enforcement, percentage of heavy spectra close to 10 tonnes per an axle are lowered than before the enforcement by the effect of overweight enforcement because the spectra are related to overweight regulation. Prediction results of pavement life for each ALS present that the ALS of HS-WIM collected before the enforcement makes the pavement life short more than others. On the other hand, the ALS of KPRP causes the longest life under same thickness of slab. Thus, it is possible that actual performance life of JCP under the traffic like ALS of HS-WIM could be short than predicted life if the pavement was designed based on ALS provided by KPRP. CONCLUSIONS : It is necessary to choose more reliable and practical ALS when designing JCP because ALS can be fairly affected by acquisition methods. In addition, it is important to extend performance life of the pavement in service by controlling traffic load such as overweight enforcement.

An Optimal Design Method for the Multidimensional Nested Attribute Indexes (다차원 중포 속성 색인구조의 최적 설계기법)

  • 이종학
    • Journal of Korea Multimedia Society
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    • v.6 no.2
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    • pp.194-207
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    • 2003
  • This paper presents an optimal design methodology for the multidimensional nested attribute index (MD-NAI) that uses a multidimensional index structure for indexing the nested attributes in object databases. The MD-NAI efficiently supports complex queries involving both nested attributes and class hierarchies, which are not supported by the nested attribute index using one-dimensional index structure such as $B^+$-tree. However, the performance of the MD-NAI is very degraded in some cases of user's query types. In this paper, for the performance enhancement of the MD-NAI, we first determine the optimal shape of index page region by using the query information about the nested predicates, and then construct an optimal MD NAI by applying a region splitting strategy that makes the shape of the page regions of the MD-NAI as close as possible to the predetermined optimal one. For performance evaluation, we perform extensive experiments with the MD-NAI using various types of nested predicates and object distribution. The results indicate that our proposed method builds optimal MD-NAI regardless of the query types and object distributions. When the interval ratio of a three-dimensional query region is 1:16:236, the performance of the proposed method is enhanced by as much as 5.5 times over that of the conventional method employing the cyclic splitting strategy.

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Design and Implementation of a Subscriber Interface Management System in ATM Network (ATM망을 위한 가입자 인터페이스 관리 시스템의 설계 및 구현)

  • Lee, Byeong-Gi;Jo, Guk-Hyeon
    • Journal of KIISE:Computing Practices and Letters
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    • v.5 no.6
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    • pp.782-792
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    • 1999
  • 효과적인 ATM 망의 관리는 연결 지향 환경, 다양한 서비스 등급, 대규모 트래픽, 가상 망 구성 그리고 여러가지 트래픽 유형 등과 같은 다양한 ATM 특성을 다룰 수 있어야만 한다. 이를 위해 ATM 포럼에서는 ATM 장치, 사설망, 공중망 및 그들간의 상호작용을 지원하기 위한 ATM 망 관리 참조 모델을 정의하였으며, 그 중 하나가 서로 다른 판매자로부터의 ATM 장비들간의 상호동작성을 보장하기 위해 SNMP 기반 망 관리 프로토콜을 통해 상호 연결된 인터페이스를 관리할 수 있도록 정의된 통합 지역 관리 인터페이스(ILMI) 프로토콜이다. ILMI의 목적은 두 인접한 ATM 장치로 하여금 그들 간에 공통의 ATM 링크에 대한 동작 파라메타를 자동적으로 구성할 수 있도록 함으로서, 관리자에 의해 수동 구성이 아닌 ATM 장치 상호간의 플러그 앤 플러그 기능을 지원하는데 있다. 본 논문에서는 이러한 ILMI 기술을 바탕으로 공중망 ATM 교환기에 연결된 가입자의 물리 인터페이스, ATM 계층 인터페이스, VPC 및 VCC의 구성 및 상태 정보를 효율적으로 관리하며, 가입자 시스템의 ATM 주소를 자동으로 등록, 관리할 수 있도록 하는 가입자 인터페이스 관리 시스템(SIMS)을 설계하고, 구현하였다. Abstract An effective ATM management must address the various features of ATM such as connection-oriented environment, varying class of service, large scale traffic, virtual network configurations and, and multiple traffic types. For this, ATM network management reference model defined by ATM Forum describes the various types of network management needed to support ATM devices, private networks, public networks, and the interaction between them. One of these types is Integrated Local Management Interface (ILMI) defined to manage interconnected interface through SNMP-based network management protocol for ensuring the interoperability of ATM devices from different vendors. The purpose of ILMI is to enable two adjacent ATM devices to automatically configure the operation parameters of the common ATM link between them and then to provide a Plug and Plug function to any ATM devices with not a passive configuration by manager but a automatic configuration. This paper design and implement a Subscriber Interface Management System (SIMS) which provide automatic registration and management of ATM address of subscriber system and efficiently manages physical interface of subscriber who is connected to public ATM switch, ATM layer interface, configuration information and status information of VPC and VCC.

Research on the number of elementary school students and class sizes in Korea (전국 초등학교 재학생수 및 학급수 조사 연구)

  • Yoon, Yong-Gi
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.18 no.3
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    • pp.50-59
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    • 2019
  • The results of a survey on 6,192 elementary schools across the country in April 2019 are as follows : First, there was a correlation between the number of students and the number of classes. Second, 2,788 schools (45.0%) were small schools, 1,931 schools (31.2%) were suitably sized schools, and 1,473 schools (23.8%) were large schools among the 6,192 elementary schools surveyed. Third, there was a significant difference in the proportion of small schools, suitably sized schools, and large schools by province. Among the 8 metropolitan cities, Seoul had the lowest percentage of small schools at 9.8%, followed by Incheon at 18.0%. Among the 9 provinces, Gyeonggi Province had the lowest rate at 26.8%, while Jeollanam-do had the highest rate at 87.2%. This means that adopting the same standard for abolition of small schools throughout different provinces can cause serious problems. Therefore, it is necessary to reflect the educational conditions of each province.