• Title/Summary/Keyword: Dominant frequency

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Plants Invasion in Large-scale Cutting Slopes in the Part of Jeollanamdo (전라남도 일부지역 대규모 절토비탈면의 식물침입)

  • Park, Moon-Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.4
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    • pp.32-42
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    • 2005
  • To investigate the plants invasion process and dominant species in large-scale cutting slopes, slopes elapsed one year to thirteen years after construction had been selected in five counties. The obtained results are summarized as follows : The species of high appearance frequency were Alnus firma, Arundinella hirta, Miscanthus sinensi var. purpurascens, Erigeron cancdensis, Artemisia princeps var. orientalis, Oenothera odorata, Lactuca raddeana, Lactrca indica var. laciniata, Lespedeza bicolor, Youngia sonchifolia, Populus albaglandulosa, and so on. The biological type of identified vascular plants was $Ch-D_1-R_{5-e}$. In time, plant coverage was increased gradually and average of plant coverage was 1.17% in slopes which elapsed one year, 42.44% after six years, 56.67% after eight years, and 69.17% after ten years. The dominant species in the surveyed slopes were covered with Alnus firma, Artemisia princeps var. orientalis, Erigeron cancdensis, Miscanthus sinensi var. purpurascens, Arundinella hirta, Lactuca raddeana, Oenothera odorata, Boehmeria spicata, Kummerowia striata and Artemisia montana of the 59 species. The conditions of location in large-scale cutting slopes are hard to fix and germinate of seeds, and extend plant roots in the slope soil. Hence, the highly appearance species and dominance species of the area will make plant coverage quick and slope stable.

The Characterization of Fish Communities in Agricultural Reservoirs (농업용 저수지의 어류군집 특성)

  • Yoon, Ju-Duk;Jang, Min-Ho;Kim, Myoung-Chul;Nam, Gui-Sook;Hwang, Soon-Jin;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.39 no.1 s.115
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    • pp.131-137
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    • 2006
  • Most South Korean lakes are middle/small size artificial reservoirs, which are almost agricultural reservoirs (17,956). A total of 67 species (21 families) were recorded and collected from 65 agricultural reservoirs though field samplings and literature surveys. Dominant species was Pseudorasbora parva (relative abundance 24.5%), and Carassius auratur (41 sites) was the highest frequency. Feeding group of fish communities in the reservoirs was as follows: carnivorous (16.2%), omnivorous (79.5%) and herbivorous fish (4.3%). The number of individuals (P=0.024), species number (P=0.047) and carnivores number (P=0.024) were significantly correlated with reservoir ages. Reservoirs were classified into 3 groups according to feeding patterns of carnivore, omnivore and herbivore groups. The omnivores were dominant group in agricultural reservoirs. Detailed studies on fish community will be a base for the understanding of food web structure and biomanipulation in reservoir systems.

Identification of Gear Noise for Industrial Robots (산업용 로봇의 기어소음 특성 고찰)

  • Kim, Dong-Hae;Lee, Jong-Moon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.152-155
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    • 2002
  • An industrial robot noise has various noise sources such as gears, motors, bearings, and controller fans. Among these, gears are the most dominant source for noise. The gear noise, caused by tooth profile, elastic deformation, machining error and wear, is directly correlated with the transmission error of mating gear. Due to the fact that has several axis and many gears, it is difficult to understand the characteristics of the vibration and noise of robots. In this study, some advanced analysis techniques based on digital signal processing such as power spectrum, time spectral map, RPM map, and etc., were applied for locating the dominant frequency components of the robot noises and identifying their sources. In addition, sound quality analysis was performed in order to evaluate the operator's annoyance. The noise and vibration measurements were carried out at several points during the operation of each axis considering the effect of load and posture of the robot. Eased on the results, proper countermeasures to reduce excessive noise level have been suggested considering the characteristics of sources.

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Effects of Mixing on the Aggressive Behavior of Commercially Housed Pigs

  • Rhim, Shin-Jae;Son, Seung-Hun;Hwang, Hyun-Su;Lee, Jae-Kang;Hong, Joon-Ki
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.1038-1043
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    • 2015
  • In this study, we investigated the effects of mixing on the aggressive behavior of commercially housed pigs. The behavioral patterns of 36 groups of pigs (a total of 360 animals) were observed over 3 consecutive days directly after weaning ($25{\pm}1.2$ days of age), and 25 and 50 days later with the aid of video technology. Fight latency and total duration and frequency of fighting were significantly different among the age groups. The aggressive behaviors decreased in 75-day old pigs if compared to 25- and 50-day old animals. Moreover, dominance index (DI) was higher in 25-day old and lower in 75-day old pigs. A comparison of dominant (DI>0) and submissive (DI<0) pigs showed significant differences (p<0.05) for major aggressive behaviors in all age groups. Dominant pigs were involved in more aggressive interactions, had longer fights, and initiated more fights than submissive pigs. Post-mixing aggressive behavior was altered by previous experience of mixing. Aggressive behavior and DI are suitable methods for analyzing the effects of mixing on commercially housed growing pigs.

Current Status of Tetanus in Korea (한국에 있어서의 파상풍에 대한 고찰 (최근 10년간을 중심으로))

  • ;;;;;Ebosawa, Isao
    • Korean Journal of Health Education and Promotion
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    • v.2 no.1
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    • pp.122-132
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    • 1984
  • Aiming to obtain knowledge and information on tetanus occurrence in Korea, an analystical survey was carried out for registered and admitted patients in four large hospitals in Korea during January 1, 1974 through December 31, 1983. Tile results showed as follows: 1. 175 among total 453 tetanus patients died in the hospitals, therefore fatal rate showed as 24.1%. However, the discharged patients against doctors' advices were not included in these died cases. 2. Sex ratio of admitted tetanus patients between male and felame was shown as 3 : 1. 3. Home delivery in neonate tetanus and laceration and abrasion in non-neonate tetanus were observed as the most dominant cause of death respectively and the wound of foot lead the most dominant cause of death in the latter. 4. Clinical features of the tetanus patients on admission showed the following order in the frequency: sucking and disphagia failure(50.8%), convulsion (53.8%), trismus (50.8%). 5. The tetanus patients were terminated with mainly respiratory ani cardiac failure. 6. In the treatment for tetanus patients, airway (58.3%), intubation (45.3%) and tracheostomy(9.7%) were applied respectively.

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Practitioners' Perception on Relationship between Production Planning and Waste Occurrence in Construction Projects

  • Khanh, Ha Duy;Kim, Soo Yong
    • Journal of Construction Engineering and Project Management
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    • v.4 no.3
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    • pp.1-12
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    • 2014
  • Construction management has been suffering from many problems, which need to be solved or better understood. Most of construction projects have not achieved efficiency as expected. In this context, waste was also considered as a problem of efficiency decrease, and poor production planning was considered as a cause for waste. This study was conducted on the basis of waste concepts and production planning processes based on the philosophies of Lean Construction. A survey to find out the relationship between them was carried out through questionnaire, which was answered by experienced people in construction projects. The results have shown that frequency of wastes occurrence is quite high, and production planning processes are superficially performed in construction phase. There is a significant negative relationship between production planning and waste occurrence (r = -0.262). Weekly Work Plan (WWP) is the most dominant plan for waste control with seventeen in total of nineteen waste factors, and phase plan is the most dominant plan for two remaining waste factors. A case study was adopted to validate the relationship between production planning and waste occurrence. The results showed that the better the project was planned, the fewer the waste would occur on construction sites.

An Analysis on the Street Fashion Trend of the Adolescent in Pusan (부산지역 청소년의 스트리트 패션 경향 분석)

  • Noh, Kyung-Hye;Lee, Kyoung-Hee
    • Fashion & Textile Research Journal
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    • v.4 no.2
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    • pp.176-187
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    • 2002
  • The aim of this research is to establish basic materials for fashion merchandising by observing the street fashion of the juveniles and by analyzing their wearing, coordination and fashion trend. We have taken the photograph of the street fashion of 202 male teenagers and 265 female teenagers in Busan, and analyzed in the category of style, item, color, pattern, materials, hair style, shoes and accessories. We have concluded that the most frequent items were shirts (male), turtle neck (female) and jeans. The main style was casual just as jumper-look, sweater-look, gardigan-look. The typical female fashions that were hip-hop-look, twin neat-look, trench coat-look, were more various than male. For the color coordination, contrast color coordination was more dominant than similarity color coordination. Dominant patterns were solid, and also check and stripe patterns were frequently found in upper garment. The representative materials were soft for upper garment, and hard for trousers. Male teenagers prefer middle-length hair style and female teenagers prefer long hair style. The juveniles in Busan are wearing sports shoes and leather shoes in similar frequency. Their favorite accessories are bag, muffler and hat.

Analysis of Korean Consumer Brand Awareness and Preferred Types of Sock Design (국내 양말 소비자의 브랜드 인지도 및 디자인 선호도 분석)

  • Kim, Chil-Soon;Nam, Young-Mi;Kim, Hyun-Su
    • Fashion & Textile Research Journal
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    • v.1 no.4
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    • pp.335-341
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    • 1999
  • The purpose of this study was to develop a large representative data base for socks marketing strategy. The study was to determine socks brand awareness in ralation to segmented distribution regions and such demographic variables as sex and age. The authors also analyzed preferred design. A total of 650 questionnaires were distributed and 611 reliable ones were used for statistical analysis. A SAS statistical package including frequency tables and chi square test was used. The results are as follows: Brand awareness involves "brand recall" based on asking a person to name the brand he or she recalls first, and also "brand recognition" based on asking subjects to identify brand names from 30 given brands. 'SOCKSTOP' was found to be a dominant brand as a result of the brand recall test, and 'BYC' was found to be a dominant brand as a result of the brand recognition test. Brand recognition was significantly different in the segmented distribution regions, three age groups and different sex groups. People considered design first in purchasing sports/casual socks, while they considered color first in purchasing dress socks. The most favored type of sock style was the common crew sock type. The results of a chi square test showed that preferred type of sock design was related with the sex and age variables.

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Combustion Noise Characteristics in Gas and Liquid Flames (가스 및 분무화염의 연소소음 특성에 관한 실험연구)

  • 김호석;백민수;오상헌
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.1
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    • pp.81-91
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    • 1994
  • Combustion noise involved with chemical heat release and turbulent process in turbopropulsion systems, gasturbine, industrial furnaces and internal engines is indeed noisy. The experimental study reported in this paper is made to identify a dominant combustion noise in jet flames. Gaseous propane and kerosene fuel have been used with air as the oxidizer in a different jet combustion systems. Combustion and aerodynamic noise are studied through far field sound pressure measurements in an anechoic chamber. And also mean temperature and velocities and turbulent intensities of both isothermal and reacting flow fields were measured. It is shown that axial mean velocity of reacting flow fields is higher about 1 to 3m/sec than that of cold flow in a gaseous combustor. As the gaseous fuel flow rate increases, the acoustic power increases. But the sound pressure level for the spray flame decreases with increasing equivalence ratio. The influence of temperature in the combustion fields due to chemical heat release has been observed to be a dominant noise source in the spray flame. The spectra of combustion noise in gaseous propane and kerosene jet flame show a predominantly low frequency and a broadband nature as compared with the noise characteristics in an isothermal air jet.

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Analysis of Academic Research Trends Pertaining to Globalization of Korean Food (한식의 세계화 관련 학술적 연구 동향 분석)

  • Min, Kye-Hong
    • Korean journal of food and cookery science
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    • v.25 no.5
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    • pp.606-618
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    • 2009
  • The purpose of this study was to analyze research trends in scholarly journals that were related to the globalization of Korean food and to provide information on the future of these trends such as various creative subject selection and research methods. 70 papers pertaining to Korean food research, such as academic journals expected to be registered, and national-scale academic papers, were selected. This research was conducted from April 6 to April 22. 2009. The results of this study were as the follows: First, most of the papers, 20(28.6%), were published in the journal of Korean journal of food culture. In addition, most articles had a single author, 24(34.3%). In regard to the profession of the auther, university professor was the most frequent profession, 127 persons(68.3%). In terms of the research subjects, preference was the most dominant preference(19.2%). Investigatory research was the most frequent research method, 58 papers(82.9%). Furthermore, foreigners and natives were the most dominant research objects, 21 papers(30.0%). As for the analysis methods, frequency analysis, one-way ANOVA, T-test, reliability analysis, and factor analysis were used the most in that order. Future studies should includ papers for master's degrees and doctorial degrees.