• 제목/요약/키워드: 2SPA

검색결과 189건 처리시간 0.027초

MIMO Channel Capacity and Configuration Selection for Switched Parasitic Antennas

  • Pal, Paramvir Kaur;Sherratt, Robert Simon
    • ETRI Journal
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    • 제40권2호
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    • pp.197-206
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    • 2018
  • Multiple-input multiple-output (MIMO) systems offer significant enhancements in terms of their data rate and channel capacity compared to traditional systems. However, correlation degrades the system performance and imposes practical limits on the number of antennas that can be incorporated into portable wireless devices. The use of switched parasitic antennas (SPAs) is a possible solution, especially where it is difficult to obtain sufficient signal decorrelation by conventional means. The covariance matrix represents the correlation present in the propagation channel, and has significant impact on the MIMO channel capacity. The results of this work demonstrate a significant improvement in the MIMO channel capacity by using SPA with the knowledge of the covariance matrix for all pattern configurations. By employing the "water-pouring algorithm" to modify the covariance matrix, the channel capacity is significantly improved compared to traditional systems, which spread transmit power uniformly across all the antennas. A condition number is also proposed as a selection metric to select the optimal pattern configuration for MIMO-SPAs.

온천수를 이용한 수치료 시설의 공간구성 비교 연구 (A Comparative Study on the Spatial Composition of the Hydro-therapy Complex Using a Hot Spring Water)

  • 김인순;강병근
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제9권2호
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    • pp.17-24
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    • 2003
  • The purpose of this study was to analyze the Comparative Study to extract the spatial factor of Hydro-therapy complex in the health spa facilities that was composed of the Hydro-therapy space, sport space, leisure space, lodging space, adminstration space. The results of this study were as follows ; the hot spring complex in korea can be converted into the hydro-therapy complex. The spatial factor of functional replacement must include to the consultation room, medical cure room, inspection room and the exercise consultation pool as the consultation space.

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최근 니트웨어 패션에 나타난 ′웰빙′의 영향 - 2000년 이후의 여성복을 중심으로 - (The ′Well-Being′ Trend and Its Impacts on the Current Knitwear Fashion)

  • 김경인
    • 한국의상디자인학회지
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    • 제6권3호
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    • pp.111-121
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    • 2004
  • The influence of the 'well-being' trend on the every day life of our society can be found by recent books, articles, and magazines. The purpose of this study is to analyze the well-being trend and its effect on the current knitwear fashion. The results of this study can be summarized as follows; (1) The 'well-being' trend is very different from the past life style and it will be a preceding life style in 21st century. (2) The preference for organic food and the promotion of 'colorful menu' came from the 'well-being' trend. And, the yoga, zen, meditation, aroma-therapy, spa, and massage are also under the influence of 'well-being' trend. (3) The Neo-Hippie look and Neo-Vintage look are connected with the 'well-being' trend. (4) The influences of 'well-being' trend on the current knitwear fashion are shown in the hand knitting (bulky knit & crochet), twin sets including cardigans, hand crafted details, natural colors, and natural materials.

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Software Performance Assessment Using Goal-Question-Metric Approach

  • Mahmood, Tariq;Park, Man-Gon
    • 한국멀티미디어학회논문지
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    • 제11권6호
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    • pp.891-902
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    • 2008
  • The software once developed enters in to the $2^{nd}$ phase of its useful operational life, where it performs its functions for which it has been developed. This is an important phase of software life, wherein the developers and users have to assess the performance of the software to prolong its operational life with efficiency, effectiveness and economy. Performance of the software is based on the measurement of the quality characteristics to ascertain that it is meeting or exceeding the needs of customers in terms of its functionality, usability, efficiency, reliability, availability, maintainability, portability etc. These software quality attributes defined under ISO 9126 provide an overall good framework for assessing the performance of the software. This paper describes a Software Performance Assessment (SPA) model using the Goal-Question-Metric (GQM) paradigm which has been applied to the operational software in real context with successful results.

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신호현시 정보 제공 시스템의 시간 지연특성 연구 (A Study on the Time Delay Characteristics of Traffic Signal Phase and Timing Information Providing System)

  • 배정규;서경덕;서우창;서대화
    • 자동차안전학회지
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    • 제14권3호
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    • pp.48-59
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    • 2022
  • A V2X system can be a candidate as a means to increase the stability of autonomous vehicles. In particular, in order to implement a Level 4 or higher autonomous driving system, the application of the V2X system is essential. Wireless communication technologies applicable to the V2X system include WAVE and C-V2X. Currently, the V2X service most used by autonomous driving systems is a service that provides signal phase and timing information and since real-time characteristic is a very important, verification of this service must be done. In this paper, we measured the time delay characteristics for providing signal phase and timing information using WAVE and LTE communication, and proposed a TOD-based signal phase and timing information generation method without using V2X communication system. To analyze the time delay characteristics, RTT (Round Trip Time) was measured as a result of the measurement. Average RTT using WAVE communication was 5.84ms and was 104.15ms with LTE communication. As a result of measuring the error between the signal phase and timing information generated based on TOD and the actual traffic light state, it was measured to be -0.284~3.784sec.

"삼국사기(三國史記)"에 기록된 의약내용(醫藥內容) 분석 (Study on Medical Records In ${\ulcorner}$the Historical Records of the Three Kingdoms${\lrcorner}$)

  • 신순식;최환수
    • 제3의학
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    • 제2권1호
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    • pp.35-54
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    • 1997
  • We tried to observe the features of ancient medical practice by analysing the records related to medicine in the book, ${\ulcorner}$the Historical Records of the Three Kingdom${\lrcorner}$ of which content includes the features of medicine in mythology, plague, delivery of twins, drugs, medical system, shamanism, constitutional medicine, psychiatry, forensic medicine, deformity, a spa, medical phrase, health and welfare work, religion, death. physiological anatomy, Taoist medicine, acupuncture, the occult af of transformation and etc. Our initial concern was about where to draw line as of medical field and we defined medicine in more broad meaning. The book ${\ulcorner}$the Historical Records of the Three Kingdoms${\lrcorner}$ describes the world of mythology by way of medicine which is not clearly a conventional one. There appears records of birth of multiple offsprings 7 times in which cases are of triplets or more. Delivering multiple offsprings were rare phenomenon though such fertility was highly admired. This shows one aspect of ancient country having more population meant more power of the nation. Of those medical records conveyed in that book includes stories of childbirth such as giving birth to a son after praying, giving birth to Kim Yoo-shin after 20 months after mother's dream of conception, and a song longing for getting a laudable child. Plagues were prevalent throughout winter to spring season and one can observe various symptoms of plagues in the record. Of these epidemic diseases, cold type might have been more common than the heat one. Appearance of epidemic diseases frequently coincided with that of natural disasters that this suggests a linkage between plague and underlying doctrine on five elements' motion and six kinds of natural factors. There exists only a few names of diseases such as epidemic disease, wind disease, and syndrome characterized by dyspnea. Otherwise there appeared only afflictions that were not specified therefore it remains cluless to keep track of certain diseases of prevalence. Since this ${\ulcorner}$Historical Records of the Three Kingdoms'${\lrcorner}$ wasn't any sort of medical book, words and terms used were not technical kind and most were the ones used generally among lay people. Therefore any mechanisms of the diseases were hardly mentioned. Some of medicinal substances such as Calculus Bovis, Radix Ginseng, Gaboderma Luciderm, magnetitum were also in use in those days. 53 kinds of dietary supplies appears in the records and some of these might have been used as medicinal purpose. Records concerning dicipline of one's body includes activities such as hunting, archery, horseback riding etc. In Shilla dynasty there were positions such as professor of medicine, Naekongbong(內供奉), Kongbong's doctor(供奉醫師), Kongbong's diviner(供奉卜師). As an educational facility, medical school was built at the first year of King Hyoso's reign and it's curricula included various subjects as ${\ulcorner}$Shin Nong's Herbal classic${\lrcorner}$, ${\ulcorner}$Kabeul classic of acupuncture and moxbustion${\lrcorner}$, ${\ulcorner}$The Plain Questions of the Yellow Emperor's Classic of Internal Medicine${\lrcorner}$, ${\ulcorner}$Classic of Acupuncturer${\lrcorner}$, ${\ulcorner}$The Pulse Classic${\lrcorner}$, ${\ulcorner}$Classic of Channels and Acupuncture Points${\lrcorner}$ and ${\ulcorner}$Difficult Classic${\lrcorner}$. There were 2 medical professors who were in charge of education. To establish pharmacopoeia, 2 Shaji(舍知), 6 Sha(史), 2 Jongshaji(從舍知) were appointed. In Baekje dynasty, Department of Herb was maintained. Doing praying for the sake of health, doing phrenology also can be extended to medical arena. Those who survived over 100 years of age appear 3 times in the record, while 98 appears once. The earliest psychiatrist Nokjin differentiated symptoms to apply either therapies using acupuncture and drug or psychotherapy. There appears a case of rape, a case of burying alive with the dead, 8 cases of suicide that can characterize a prototype of forensic medicine. Deformity-related records include phrases as follow: 'there seems protrudent bone behind the head', 'a body which has two heads, two trunks, four arms.', 'a body equipped with two heads' In those times spa can be said to be used as a place for he리ing, convalescence, and relaxation seeing the records describing a person pretended illness and went to spa to enjoy with his friends. Priest doctors and millitary surgeons were in charge of the medical sevice in the period of the Three Kingdoms by the record written by Mookhoja(墨胡子) and Hoonkyeom(訓謙). Poor diet and regimen makes people more vulnerable to diseases. So there existed charity services for those poor people who couldn't live with one's own capacity such as single parents, orphans, the aged people no one to take care and those who are ill. The cause of affliction was frequently coined with human relation. There appeared the phenomenon of releasing prisoners and allowing people to become priests at the time of king's suffering. Besides, as a healing procedure, sutra-chanting was peformed. There appears 10 cases of death related records which varies from death by drowning, or by freezing, death from animals, death from war, death from wightloss and killing oneself at the moment of spouse's death and etc. There also exist certain records which suggest the knowledge of physiology and anatomy in those times. Since the taoist books such as ${\ulcorner}$Book of the Way and Its Power(老子道德經)${\lrcorner}$ were introduced in the period of Three Kingdoms, it can be considered that medicine was also influenced by taoism. Records of higher level of acupuncture, records which links the medicine and occult art of transformation existed. Although limited, we could figure out the medical state of ancient society.

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필름기재 표면 코팅제의 첨가물질 조성 조건에 따른 수분산 안료잉크의 프린팅 성능 평가 (Printing Performance Evaluation of Water-dispersed Pigment Ink according to Additive Conditions of Film Substrate Surface Coating Agent)

  • 김혁진;서혜지;강은하;한민우;이동현;권동준;홍진표
    • 한국염색가공학회지
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    • 제35권4호
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    • pp.196-205
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    • 2023
  • Water-dispersed pigment is on-going study for without air pollution in the textile and print industry. Primer treatment is essential for the substrate to improve the printing quality of eco-friendly water-dispersed pigment ink. Otherwise in the case of untreated primer, the water-dispersed pigment ink will dry onto the surface and cause defective images. This study was conducted on film substrate coating (primer) to fix eco-friendly water-dispersed pigment ink on film substrate. The drying, bleeding, and color strength of the pigment ink were examined depending on the composition and mixing ratio of the coating solution. The mixing ratio of silica gel in the coating film is increased to 0, 0.5, 1, 2 and 3 and results that DK-1-3 of silica gel ratio of 1 showed the lowest bleeding such as 52%, the letter thickness of 0.76mm and DK-1-5 of SG ratio of 3 showed the highest bleeding such as 304%, the letter thickness of 2.02mm. The mixing ratio of SPA in the coating film is increased to 2.5, 5, 7.5, SPA ratio of 7.5 has a bleeding ratio of 9% and letter thickness of 0.544mm. It showed the closest value to 0.5mm. According to the result, the optimal mixing ratio of binder, polymer coagulant, silica gel is 100:7.5:1.

RSA 충돌 분석 공격 복잡도 향상을 위한 연구 (Study for improving attack Complexity against RSA Collision Analysis)

  • 심보연;원유승;한동국
    • 정보보호학회논문지
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    • 제25권2호
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    • pp.261-270
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    • 2015
  • 스마트카드와 같은 정보보호 디바이스에서 데이터를 보호하기 위해 사용되는 RSA 암호 알고리즘은 부채널 분석에 취약함이 밝혀졌다. 특히 암호 알고리즘이 수행되는 동안 소비되는 전력 패턴을 관찰하여 분석에 활용하는 전력 분석공격에 취약하다. 전력 분석 공격은 대표적으로 단순 전력 분석과 차분 전력 분석이 있고, 이 외 충돌 분석 등이 있다. 그 중에서 충돌 분석은 단순 전력 분석 및 차분 전력 분석에 안전하게 설계된 RSA 암호 알고리즘이라도 단일 파형을 이용하여 비밀 키 값을 찾을 수 있는 매우 강력한 공격기법이다. 따라서 기존 메시지 블라인딩 기법에 윈도우 기법을 적용한 대응기법이 고려되었지만, 이는 윈도우 크기가 작은 환경에서 충분히 큰 안전도를 제공하지 못한다. 이에 본 논문에서는 메시지 블라인딩 기법과 윈도우 기법이 적용된 RSA 암호 알고리즘에 지수 분할 기법을 혼합 적용하여 충돌분석에 더 높은 안전도를 제공하는 대응기법을 제시한다. 실험을 통해 본 논문에서 제시하는 대응기법이 윈도우 크기가 작은 환경에서 메시지 블라인딩 기법과 윈도우 기법만 적용된 기존 RSA 암호 알고리즘 보다 공격 복잡도가 약 124% 향상되어 더 높은 안전도를 제공함을 보였다.

칩 기반 등온증폭법을 이용한 약제 내성 포도상구균의 검출 (Detection for Methicillin Resistant Staphylococcus aureus in Using Bio-Chip Based Loop Mediated Isothermal Amplification Assay)

  • 조민호;장원철;최재구
    • 대한화학회지
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    • 제57권1호
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    • pp.81-87
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    • 2013
  • 황색포도상구균은 병원에 의한 감염, 혈류 감염을 포함하는 중요한 병원체이다. 특히, 포도상구균의 혈액 수집의 신속한 동정과 메치실린 내성이 일어나게 되면 폐혈증으로 추측되어 진다. 본 저자는 적은 양의 핵산을 등온증폭반응에 적응시켜 증폭산물을 SYBR Green I을 결합하여 염기서열에 특이적으로 검출할 수 있는 새로운 방법을 제시하고 있다. 그리고 이 독특한 유전자 증폭방법은 등온의 상태에서 하나의 효소만으로 증폭이 가능하다. 포도상구균-등온증폭반응은 황색포도상구균에 특이적인 protein A를 암호화하는 spa 유전자와, 메치실린 내성인 pennicillin-binding protein-2를 암호화하는 mecA 유전자를 타겟으로 하여 MRSA와 MRSE를 검출하였다. 본 연구에서는 등온증폭법을 사용하여 황색포도상구균과 표피포도상구균의 임상샘플을 검출하였다. 황색포도상구균과 표피포도상구균을 10배위 정량 희석하여 시리즈별로 샘플을 만들어 실험을 수행하였다. 칩을 기반으로 하는 LAMP법은 포도상구균 감염여부를 쉽고, 빠르고, 정확하게 민감도 있는 검출을 가능하게 해 주었고, 샘플을 측정할 수 있는 한계값을 넘는 상황에 특이적으로 적용할 수 있다.

NTRU 암호에 대한 전력 분석 공격 및 대응 방법 (Power analysis attacks against NTRU and their countermeasures)

  • 송정은;한동국;이문규;최두호
    • 정보보호학회논문지
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    • 제19권2호
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    • pp.11-21
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    • 2009
  • NTRU는 1990년대 Hoffstein 등에 의해 제안된 격자(Lattice) 기반 공개키 암호체계로서 기존의 공개키 암호와 비교하여 동일한 안전성을 제공하면서 암호화 및 복호화 속도가 빠르며 양자 연산 알고리즘을 이용한 공격에도 강하다는 이점이 있어 많은 주목을 받고 있다. 본 논문에서는 단순 전력 분석 공격과 통계적 특성을 이용한 전력 분석 공격인 상관계수 전력 분석 공격에 대한 NTRU의 안전성을 분석하고, NesC로 구현한 NTRU의 연산을 Telos 모트(mote)에서 수행시켜 측정한 전력 소모 데이터에 상관계수 전력 분석 공격을 적용하여 개인키 정보를 복원하는 실험 결과를 보인다. 또한 이러한 전력 분석 공격을 방지하기 위한 대응 방법을 제시한다. 먼저, 단순 전력 분석 공격을 방지하기 위해 연산 결과를 저장할 배열을 0이 아닌 수로 초기화시키는 방법을 제안하고, 통계적 특성을 이용한 전력분석 공격을 방지하기 위해 연산 순서를 변경하거나 컨볼루션(convolution) 연산에 사용되는 피연산자들에게 무작위성(randomness)을 부여하여 같은 입력에 대해서 랜덤한 전력 소모를 보이도록 하는 방법을 제안한다.