• Title/Summary/Keyword: 단분산

Search Result 1,021, Processing Time 0.031 seconds

A Review on the Sampling Design for Energy Consumption Survey in Agricultural Sector (농업부문 에너지 소비량 조사를 위한 표본설계)

  • Kim, Yean-Jung;Kim, Bae-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.9
    • /
    • pp.411-417
    • /
    • 2017
  • It is necessary to determine the current and future energy consumption by farm households for the rational specification of energy related policy in the Korean agricultural sector. Especially, It is important to identify the consumption by source of energy and by the crops. On the other hand, the world has tried to reduce the production of greenhouse gases and, in line with this, the Korean government established related legislations to contribute to this reduction (30% reduction in emissionsby 2020). The reduction target of the agricultural sector is specified as 5.2% of the national total. This study focuses on sampling design to determine the energy consumption and emission of greenhouse gases, and suggests several alternatives to improve the confidence level and to make a dent survey and estimation errors. The population for the energy consumption survey of the agricultural sector was derived from agricultural census data. In the case of commodities with high skewness, we cut the sample range to within the statistical significant range. The number of samples in each class is specified using the Neyman allocation method and 95% significance level. The estimation results are compared with the population to verify the statistical significance and several management methods of sampling errors are suggested.

An Analysis of 'One Book's Selected in Twenty Years of 'One Book, One City' Reading Campaigns in the U.S.A. (미국 '한 책, 한 도시' 독서운동 20년과 '한 책'의 분석)

  • Yoon, Cheong-Ok
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.51 no.3
    • /
    • pp.45-64
    • /
    • 2017
  • The purpose of this study is to understand the direction of the community reading campaign in the U.S.A. known as 'One Book, One City' reflected in the books selected for this campaign for the past 20 years in terms of their classification numbers, subject headings, publication dates, and genres. Analyzed are the author and state lists of 'One Book, One City' Reading Promotions Projects available from the website of the LC (Library of Congress) Center for the Books, and bibliographic records of 735 books selected in only one 'One Book' program, accessed from LC OPAC. Major findings include continuing influences of the all-time favorite 'One Book' selections, including To Kill a Mockingbird and the extension of their span of life through The Big Read, preference for the recent publications, importance of P (Literatures and Languages) Class (530 titles, 72.1%) and PS(American Literatures) subclass (307 titles, 57.9%) in the LC Classification Scheme, distribution of books in 43 genres, including domestic fiction, historical fiction, and psychological fiction, etc., the use of 535 unique LC subject headings and much interests in "City and town life" (10 titles) and "World War, 1939-1945" (8 titles), and prominence of subject groups which begin with "African American..." and "Woman..." out of 96 groups of subject headings. It is found that the subjects and focus of the selected books expand from integration, understanding, integrity to human rights, environment, peace, etc. The limitations of this study is that the influence of the selected books and the changes in communities are not properly analyed.

A study on the Initial Nanopore Formation in the Calix Arene Based Porogen Templated Porous Thin Film (칼릭스아렌 포로젠을 이용한 다공성 박막의 초기 나노기공 형성과정에 관한 연구)

  • Kim, Do-Hun;Yim, Jin-Heong
    • Korean Chemical Engineering Research
    • /
    • v.49 no.5
    • /
    • pp.669-675
    • /
    • 2011
  • Fourier Transform Infrared Spectroscopy and in-situ Position Annihilation Lifetime Spectroscopy(PALS) analysis of hybrid film, which consist of silsesquioxane(SSQ) and 4-tert-butyl calix[4]arene-O,O',O",O'"-tetraacetic acid tetraethyl ester(CA[4]) have been investigated in order to understand initial formation of nanopore in the next generation porous low-k dielectrics(k < 2.0). SSQ/CA[4] can provide effective homogeneous thin film having porous structure. The porogen decomposition behavior were completely different in the two kinds of SSQ/CA[4] based hybrid film (i.e. SSQ/CA[4] 10 and SSQ/CA[4] 20%). Relatively small pores(1.5 nm) come from dispersion of uni-molecular CA[4] in the SSQ matrix have been generated at $300^{\circ}C$, while mesopores(2.5~3.0 nm) induced from self assembled CA[4] have been generated at $250^{\circ}C$. It might be due to highly interconnected structure of SSQ/CA[4] 20% hybrid thin film resulting in facile evacuating of decomposed fragment of CA[4] molecule.

An study on guide to oil spill response in snow and ice condition in seas (유빙유입에 따른 해양오염사고 대응방안 마련 연구)

  • Lim, Ji Young;Lee, Seung Hwan;Hyun, Chung Guk;Park, Chan Hyun
    • Proceedings of KOSOMES biannual meeting
    • /
    • 2018.06a
    • /
    • pp.16-16
    • /
    • 2018
  • 2017년 겨울, 기록적인 한파로 인해 바다가 얼면서 인천 앞바다로 유빙이 유입되었다. 2013년 해상에서 유빙이 발견된 이후 약 5년만에 다시 유빙이 등장한 것이다. 중부청 소속 항공단 순찰결과에 따르면, 2018년 1월 12일 인천대교 인근 해상에서 최초로 발견된 이후 강화 연안, 영종도 북단 등 해상에서 광범위하고 불규칙한 형태로 유빙이 분포되어 있는 것으로 나타났다. 유빙의 문제점은 해상에서 선박의 안전운항을 저해하고 경비함정의 안전에 지장을 초래하며 기름 유출 시, 유출유의 거동 특성이 달라져 일반적인 방제방법의 적용이 곤란한 점이다. 이에 따라 해상에서의 해양오염사고 대응방안 마련을 위해 저온 및 유빙 유입 해상에서 유출유의 거동 특성을 알아보았다. 구분인자를 극한의 추위(Extreme Cold), 유빙(Pack Ice), 정착빙(Fast Ice) 3가지로 분류하여 기름의 성상변화 및 시사점을 살펴보고, 유출된 기름의 효율적 방제를 크게 3가지로 분류(기계적 봉쇄 및 회수, 화학적 분산제의 사용, 현장소각)하였다. 일반적인 방제장비를 저온 및 얼음분포 해상에서 사용 시 슬러시화 된 얼음으로 인해 유출유 회수가 어렵고, 동결온도에서 장비가 오작동할 우려가 있다. 이미 북유럽 국가에서는 극한의 추위와 얼음분포 해상에 특화된 방제장비를 도입하여 해양오염대비 대응을 하고 있다. 2003년 3월 발틱해에서 불법적으로 유출한 선저폐수를 특화 장비는 brush bucket 유회수기 이용 방제조치한 사례가 있으며, 2006년 5월 같은 장소에서 선박 침몰로 인한 기름 유출이 발생했을때도 brush bucket 유회수기 이용 방제조치를 하였다. 국내에도 이상 기후로 인해 기록적인 한파가 지속되면서 북극에서나 볼 법한 유빙들이 발견되고, 해양오염사고는 언제 어디서나 발생할 수 있으므로, 해양오염방제의 임무를 맡고 있는 국가기관으로써 특수한 환경까지도 고려하여 대응방안을 마련할 필요가 있다. 해양오염이 재난으로 인식되고 있는 상황에서, 그리고 지구온난화로 인한 이상기후변화가 지속되는 상황에서 겨울철 유빙 유입은 점점 더 많아질 수 있다. 본 연구에서는 자료나 방제경험이 부족하므로 일찌감치 북극항로 개발로 앞선 방제기술과 경험을 가지고 있는 북극이사회를 벤치마킹하여 관할 해역 특성에 맞는 대응방안을 고찰해 본다.

  • PDF

SOFT TISSUE PROFILES OF YOUNG ORIENTAL ADULTS (아시아 성인 연조직 측모의 비교분석)

  • Chung, Kyu-Rhim;Park, Young-Guk;Chu, Stephen;Fu, Min-Kui
    • The korean journal of orthodontics
    • /
    • v.27 no.6 s.65
    • /
    • pp.881-889
    • /
    • 1997
  • The purpose of this study was to compare four groups of Oriental young adults (169 males and 174 females) with normal occlusion and well balanced faced. Lateral cephalograms of 100 Koreans, 100 Chinese, 72 Vietnamese and 71 Japanese were digitized and six profile measures were computed. Analyses of variance showed that total facial profile(Gl'-Pr'-Pg') of Chinese was significantly less convex than the profile of Koreans or Vietnamese. Facial profile(Gl'-Pr'-Pg') of Chinese was also significantly less convex than that of Vietnamese. Holdaway's soft tissue angle(Pg'-LS:N-B) was significantly greater in Vietnamese than Chinese and Koreans, who were in turn greater than Japanese. The upper lip of Vietnamese is significantly closer to Ricketts' esthetic plane, than Chinese; Koreans and Japanese are significantly further behind the plane than Chinese. The lower lip of Koreans and Japanese was close to the esthetic plane, while Chinese and Vietnamese were approximately 2mm ahead. The nasolabial angle was significantly smaller for Chinese and Japanese than Koreans and Vietnamese. Sex differences were primarily dependent on the nose; total facial convexity and the nasolabial angle wert significantly larger in females than males. The results of this study demonstrate that a single standard of facial Profile is not sufficient or appropriate for Oriental patients.

  • PDF

A Study Concerning of Servant Leadership of Radiotechnologist (방사선사의 서번트 리더십에 관한 고찰)

  • An, Hyun;Ko, Seong-Jin;Kang, Se-Sik;Kim, Dong-Hyun;Kim, Chang-Soo;Kim, Jung-Hoon
    • Journal of radiological science and technology
    • /
    • v.35 no.3
    • /
    • pp.201-210
    • /
    • 2012
  • This study aimed to look at servant leadership that general radiotechnologist perceive from the servant leadership perspective and based on this to suggest ways to improve not only organizational effects of radiotechnologist who work clinically but also their working conditions. A population of 290 radiotechnologist who work at hospital in Pusan was the subject of this study and a survey was conducted to them. The analysis for the collected data used SPSS/PC+Win13 version and one-way, ANOVA was carried out to verify differences between groups. Servant leadership according to background factors showed relatively higher values among unmarried than married, twenties or more in terms of age, and nuclear medicine department in terms of the work department than other groups. Regular positions in terms of work types and university hospitals in terms of hospital types showed high scores, and as the motive for being a radiotechnologist, many considered job prospects. Hospitals should improve the organization's ability and performance by managing human resources efficiently. According to this study, servant leadership that radiotechnologist serve the community based on true prestige with basic honesty and trust as a member of fair community is a new model of true leadership that the future society requires.

Evaluation of Aging Characteristics of Selected PMA using HP-GPC (HP-GPC를 이용한 폴리머개질 아스팔트의 노화특성 분석)

  • Kim, Kwang-Woo;Doh, Young-Soo;Amerkhanian, Serj N.
    • International Journal of Highway Engineering
    • /
    • v.6 no.2 s.20
    • /
    • pp.15-24
    • /
    • 2004
  • Oxidation causes increment of the quantity of large molecular size or LMS in asphalt and is a major reason for hardening of asphalt binder. An extended service life of pavement on a road is expected by reducing oxidation of binder. Oxidation of binder occurs during hot mixing with aggregates before placement on road and then during in-service after the asphalt pavement is constructed. Quantitative increase of LMS as result of aging after RTFO and PAV was analyzed based on the data from high-pressure gel-permeation chromatography (HP-GPC). Polymer modified asphalt (PMA) after RTFO procedure showed 20-30% increment in LMS and then after PAV procedure more than twice, although the percentage of increment was different according to asphalt brand and grade. The PMAs containing LDPE or SBS, which showed a great mechanical property improvement in previous studies, were selected for characterizing PMA aging In this study. Considerably reduced increment of LMS was observed from the PMA containing LDPE after RTFO and PAV procedures. The GPC result showing the binder with less LMS increment means that the asphalt while being mixed with LDPE was aged less during the aging treatment. The dispersed particle of LDPE in asphalt cement seems to disturb oxidative aging reaction and evaporation.

  • PDF

Breeding of Pleurotus eryngii with a high temperature tolerance trait (고온적응성 큰느타리(새송이)버섯 품종육성)

  • Im, Chak Han;Kim, Min-Keun;Kim, Kyung-Hee;Cho, Soo Jeong;Lee, Jong Jin;Joung, Wan-Kyu;Lee, Sang Dae;Choi, Young Jo;Ali, Asjad;Ryu, Jae-San
    • Journal of Mushroom
    • /
    • v.12 no.3
    • /
    • pp.187-192
    • /
    • 2014
  • In order to breed a new P. eryngii cultivar with high temperature tolerance trait to cope with climate change, strains and cultivars were characterized at $20^{\circ}C$ that is $5^{\circ}C$ higher than normal condition followed by screening for the characteristics such as required days to harvest, quality and yield. Monokaryons from the selected strains were crossed. $Da-32{\times}KNR2322-15$ derived from the crosses between KNR2322 having characteristics of short growing day and Da($Ga5Na5-4{\times}KNR2312-7$) having charateristics of high guality and yield at $20^{\circ}C$, showed 14.9 days for harvest, 120.6 g yield, and 7.0 quality in the first trial. The strains were named as Taeyangsongi and cultivated on a large scale to compare with Kenneutari No. 2 at a mushroom farm. Yield of Taeyangsongi (109 g) was significantly different(P=0.001) from Kenneutari No.2. Quality of the new (6.6) and the reference cultivar (3.5) was also statistically different (P=0.001) The brightness of pileus of Taeyangsongi (59.5) was 10 points less than the reference cultivar due to which it has an inability to bear high temperature stress. Thus, PCR reactions with URP2 discriminated between Taeyansongi and reference cultivars (Keneutari No. 2 and Aeryni).

Vehicle HUD's cognitive emotional evaluation - Focused on color visibility of driving information (차량용 HUD의 인지적 감성 평가 -주행정보의 색채 시인성을 중심으로-)

  • Choi, Won-Jung;Lee, Won-Jung;Lee, Seol-Hee;Park, YungKyung
    • Science of Emotion and Sensibility
    • /
    • v.16 no.2
    • /
    • pp.195-206
    • /
    • 2013
  • The main causes of traffic accidents while driving a car is of the driver's visual distraction. In this study, the color sensitivity of the information projected on the windshield were evaluated for HUD (Head Up Display) system which helps the driver's eyes on the road while driving. The driving Information were projected $9^{\circ}$ downward from front sight $0^{\circ}$ under lab's fluorescent lights, LED floorlights and the TV had having 25 [lux] illumination when driving at night environment and 100,000 [lux] of daylight environment. Munsell color hue of the basic five colors (R, Y, G, B, P) and the color of traffic lights YR, W were the color of the seven characters, each character were outlined by White, Gray except for W. Total of 19 experimental stimuli was shown in the environment of day and night driving for asking visibility information of color, fatigue, preferences, and evaluate the degree of interference. The results came out that the bright Y and G color is visibility significantly for daylight. Second, with the outline of the text, the color of the outline works as a background for luminance contrast effects and affects visibility. Third, without the outline, the glass in front of the vehicle acts as the background and the luminance contrast of characters achieve greater brightness and visibility. The luminance contrast between the stimuli and background should be considered for increasing color visibility for driving information which is an important factor for HUD commercialization.

  • PDF

A Effect of Frequency Response Effect of Butter-Worth Filter on Optical Receive System (광 수신시스템에서 버터워쓰필터의 주파수 응답 효과에 관한 영향)

  • Kim, Sun-Yeob
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.2
    • /
    • pp.25-31
    • /
    • 2020
  • In an optical system that serves as the backbone of an information transmission system, it is essential to evaluate the statistical characteristics of the signal and noise for a performance evaluation and optimization of the system. The optical receiver system improves the reception sensitivity by adopting an optical amplifier in front of the optical detector to improve the reception sensitivity, but some problems change the bandwidth of the electronic signal to the optical signal in the optical receiver due to the ASE noise added to the output of the optical detector. The problem of changing the ratio of the bandwidth of these signals varies according to the passband characteristics of the filter present at the output stage. The frequency response effect can be solved by constructing an infinite order filter, but it is almost impossible to implement it. In this paper, the Butterworth filter was implemented to evaluate the frequency response characteristics of an optical receiver system according to the filter order. The simulation results showed that the receiver sensitivity increases as the order of Butter-Worth filters increases. In addition, as a result of simulation of the change of various values, it was confirmed that the reception sensitivity increased with increasing. That is, the average photocurrent increases, and the dispersion decreases with increasing.