• Title/Summary/Keyword: Frequency Partition

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A Study on Office Workers' Preference for Spatial Characteristics of Home Office (재택근무 희망 근로자의 재택 근무 공간 특성에 대한 선호 연구)

  • 신화경
    • Journal of the Korean housing association
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    • v.12 no.2
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    • pp.87-95
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    • 2001
  • The number of people working in their own home has been increasing, and this will change the form of house. Therefore, it is necessary to plan the new house for the people working at home, and to offer business related working area. This study was designed to know the office workers preference for spatial characteristics of home office. Data were collected through a questionnaire survey. The subject were 257 office workers living in Seoul area. Frequency, percentage, and MM2 : $\textrm{X}^2$-test were used. The results showed that the place for home-office should be located independently inside house. The desirable size for the home-office might be 3-4 pyung. If the place for home-office share with other places, livingroom of bedroom, it is necessary to develop furniture and partition matching with residential furniture and atmosphere. Office workers prefer U-shaped workstation and coner-shaped workstation.

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Design of broadband low noise balanced amplifier (광대역 저잡음 평형 증폭기 설계)

  • 이정란;문성익;양두영
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.191-194
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    • 1999
  • The balanced amplifier is a practical amplifier to, implement a broadband amplifier that has flat gain and good input and output VSWR. Three-stage amplifier design procedure usually divided into three partition satisfying the following requirements : low noise figure, high gain and high power output. FHX35LG HEMT device is used in the design can be obtained low noise figure at the first-stage, MGA82563 MMIC device is used in the design can be maintained high gain at the second-stage, and AHI MMIC device is used in the design can be required high power output at the third-stage. The results of three-stage balanced amplifier show that power gain is about 40㏈, noise figure is less than 1.2㏈ at operating frequency.

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Comparative Study on the Structure of Vascular Cambium in Some Salicaceae (수종의 버드나무과 유관속 형성층의 구조에 관한 비교연구)

    • Korean Journal of Plant Resources
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    • v.11 no.3
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    • pp.326-334
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    • 1998
  • Vascular cambium in 16 species of Salicaceae is nonstoried in all of them and is made up of fusiform and ray initials. The growth of cambial girth occurred by pseudotransverse division of fusiform initials and subsequent apical intrusive growth of daughter initials. The measurements of fusiform initials in tangerntial sections have revealed that the average length varies from 252.2-437.1${\mu}{\textrm}{m}$ in investigated species, with the maximum being in Populus euramericana and the minimum in Salix purprea var. Multinervis. The length of fusiform initials depends on the length of the tapering end wall , therefore, the longer the length of the tapering end wall, therefore, the longer the length of the taperding end wall, the longer the length of fusiform initials. Ray initials have their own size, magnitude, and frequency of occrrence in each species. The relative proportion of ray initials fall about 15.0-24.5% in Salicaceae. Shrubby species of Salix have a lower ratio of ray initials than the species which possess wider trunks. New ray initials are originated from cut off the side or the end of fusiform initials and central partition of a fusiform initials.

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Recommendation System using Associative Web Document Classification by Word Frequency and α-Cut (단어 빈도와 α-cut에 의한 연관 웹문서 분류를 이용한 추천 시스템)

  • Jung, Kyung-Yong;Ha, Won-Shik
    • The Journal of the Korea Contents Association
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    • v.8 no.1
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    • pp.282-289
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    • 2008
  • Although there were some technological developments in improving the collaborative filtering, they have yet to fully reflect the actual relation of the items. In this paper, we propose the recommendation system using associative web document classification by word frequency and ${\alpha}$-cut to address the short comings of the collaborative filtering. The proposed method extracts words from web documents through the morpheme analysis and accumulates the weight of term frequency. It makes associative rules and applies the weight of term frequency to its confidence by using Apriori algorithm. And it calculates the similarity among the words using the hypergraph partition. Lastly, it classifies related web document by using ${\alpha}$-cut and calculates similarity by using adjusted cosine similarity. The results show that the proposed method significantly outperforms the existing methods.

Distribution Properties of Heavy Metals in Goseong Cu Mine Area, Kyungsangnam-do, Korea and Their Pollution Criteria: Applicability of Frequency Analysis and Probability Plot (경남 고성 구리광산 지역의 중금속 분산특성과 오염기준: 빈도분석과 확률도의 적용성)

  • Na, Choon-Ki;Park, Hyun-Ju
    • Journal of Environmental Science International
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    • v.17 no.1
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    • pp.57-66
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    • 2008
  • The frequency analysis and the probability plot were applied to heavy metal contents of soils collected from the Goseong Cu mine area as a statistic method for the determination of the threshold value which was able to partition a population comprising largely dispersed heavy metal contents into the background and the anomalous populations. Almost all the heavy metal contents of soil showed a positively skewed distributions and their cumulative percentage frequencies plotted as a curved lines on logarithmic probability plot which represent a mixture of two or more overlapping populations. Total Cu, Pb and Cd data and extractable Cu and Pb data could be partitioned into background and anomalous populations by using the inflection in each curve. The others showed a normally distributed population or an largely overlapped populations. The threshold values obtained from replotted frequency distributions with the partitioned populations were Cu 400 mg/kg, Pb 450 mg/kg and Cd 3.5 mg/kg in total contents and Cu 40 mg/kg and Pb 12 mg/kg in extractable contents, respectively. The thresholds for total contents are much higher than the tolerable level of soil pollution proposed by Kloke(Cu 100 mg/kg, Pb 100 mg/kg, Cd 3 mg/kg), but those for extractable contents are not exceeded the worrying level of soil pollution proposed by Ministry of Environment(Cu 50 mg/kg, Pb 100 mg/kg). When the threshold values were used as the criteria of soil pollution in the study area, $9{\sim}19%$ of investigated soil population was in polluted level. The spatial distributions of heavy metal contents greater than threshold values showed that polluted soils with heavy metals are restricted within the mountain soils in the vicinity of abandoned mines.

(Very Low Bitrate Image Compression Coding Based on Fractal) (프랙탈 기반 저전송율 영상 압축 부호화)

  • 곽성근
    • Journal of the Korea Computer Industry Society
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    • v.3 no.8
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    • pp.1085-1092
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    • 2002
  • Studies on image information processing have been performed since long time ago because in daily life most of information are acquired by the since of sight. Since there should be a lot of data to describe image as a digital form, data compression is required in order to store or transmit digital image. Lately among most of image compression methods adopted on image compression standards, transform coding methods have been primarily used which transforms the correlations between pixels of image on frequency domain before image compression. It is blown that the standard methods using especially DCT features blocking effect which is the major cause of degrading the quality of image at high compression rate. Fractal encoding using quadtree partition is applied after reducing original image, and we are to find a optimal encoding for the number of scaling bit and offset bit.

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Optimized Design of Wide-Band Subarray Using a Genetic Algorithm (유전 알고리즘을 이용한 광대역 부배열 최적화 설계)

  • Kim, Doo-Soo;Lee, Dong-Koog;Kim, Seon-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.4
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    • pp.415-423
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    • 2012
  • This paper specifies on optimized design of wide-band subarray using a Genetic Algorithm. First wide-band radiator was designed at triangle lattice of infinite array structure. It is the radiator of notch type that has a wide-band characteristic of ratio 2:1 between maximum and minimum frequency satisfying active reflection coefficient under -10 dB at boresight. And a Genetic Algorithm was applied to optimize subarray partition of antenna consisting of 1,100 array elements. It was confirmed that an optimized subarray antenna has a 4.5-5.5 dB more improved maximum SLL (Side-Lobe Level) than regular subarray antenna.

Genetic Variation of Monilinia fructicola Population in Korea

  • Su In Lee;Hwa-Jung Lee;Youn-Sig Kwak
    • The Plant Pathology Journal
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    • v.40 no.2
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    • pp.205-217
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    • 2024
  • Brown rot disease, caused by Monilinia spp., poses a significant threat to pome and stone fruit crops globally, resulting in substantial economic losses during pre- and post-harvest stages. Monilinia fructigena, M. laxa, and M. fructicola are identified as the key agents responsible for brown rot disease. In this study, we employed the amplified fragment length polymorphism (AFLP) method to assess the genetic diversity of 86 strains of Monilinia spp. isolated from major stone fruit cultivation regions in South Korea. Specifically, strains were collected from Chungcheong, Gangwon, Gyeonggi, Gyeongsang, and Jeolla provinces (-do). A comparative analysis of strain characteristics, such as isolation locations, host plants, and responses to chemical fungicides, was conducted. AFLP phylogenetic classification using 20 primer pairs revealed the presence of three distinct groups, with strains from Jeolla province consistently forming a separate group at a high frequency. Furthermore, M. fructicola was divided into three groups by the AFLP pattern. Principal coordinate analysis and PERMANOVA were applied to compare strain information, such as origin, host, and fungicide sensitivity, revealing significant partition patterns for AFLP according to geographic origin and host plants. This study represents the utilization of AFLP methodology to investigate the genetic variability among M. fructicola isolates, highlighting the importance of continuous monitoring and management of variations in the brown rot pathogen.

Comparison of Dynamic Property Estimation by Transient Vibration and Synchronized Human Excitation (건물의 상시진동계측과 인력가진계측을 통한 동적특성 비교)

  • Jang, Young-Ju;Cho, Bong-Ho;Kim, Hong-Jin
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.259-266
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    • 2011
  • The transient vibration test and synchronized human excitation is performed for low-rise concrete buildings and their identified natural frequency, damping ratio, and mode shape are compared. Form the identified dynamic parameters, it was found that the damping ratio obtained through the synchronized human excitation test is greater than those obtained from the transient vibration test. However, the mode shapes of the first mode are not significantly different regardless of the test method. Further, the stiffness of the interior brick partition considerably affect the stiffness of the entire building such that the first natural mode of rectangular shaped building occurred in the longitudinal direction rather than transverse direction.

Design of a Low Bit-rate Speech Coder Based on Mixed Multi-band Excitation Model (혼합 다중대역 여기모델에 기반한 저 전송률 음성 부호화기의 설계)

  • 한우진;오영환
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.6
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    • pp.510-521
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    • 2002
  • MBE (multi-band excitation) coder can achieve high qualify synthetic speech below 4.0 kbps. There are, however, significant differences of the fine structure between the original spectrum and the synthetic spectrum. They are mainly due to the exclusive partition of voiced and unvoiced regions in frequency domain and the decision procedure based on the experimental threshold. This paper proposes MMBE (mixed multi-band excitation) speech model to overcome drawbacks of a MBE coder. In addition, two analysis methods, which do not need my decision procedure based on a threshold, are presented. Both voiced and unvoiced components can be mixed over all the frequency axis in the MMBE speech model. To illustrate the potential of the proposed speech model, we develop a 2.6 kbps MMBE coder and compare it with a 2.9 kbps MBE coder by both objective and subjective methods. The results have shown that the proposed coder has a better performance even at a lower bit-rate compared with the MBE coder.