• Title/Summary/Keyword: WAVE EXPOSURE

Search Result 163, Processing Time 0.037 seconds

The Analysis of planning methode and case study for Model 'Climate Change Adaptation City' (기후변화 적응도시 모델개발을 위한 계획기법 및 사례 분석)

  • Kim, Jongkon
    • KIEAE Journal
    • /
    • v.12 no.4
    • /
    • pp.13-19
    • /
    • 2012
  • The Earth's surface temperature still continues to rise, and extreme weather phenomena such as heat waves, drought, and precipitation have been repeated every year. It is reported that international communities attribute the main cause of the Earth's surface temperature rise to the excessive use of the fossil energy. Recently, the damage caused by climate change is getting worse, and the place where we live is suffering the most. Cities have been continuously growing not only meeting the basic functions of human habitation, work and leisure but also being places for various economic and social activities. But Cities, the victims of climate change, have grown only considering human needs and convenience rather than predicting their physical and ecological systems(Albedo effects, urban microclimate, resources and energy of the circulatory system, etc). In other words, the cities offer the cause of the problems of climate change, and even worsen the extreme weather phenomena without coping with them. Therefore, it is urgent priorities to protect the climate, to prevent the causes of the extreme weather phenomena and to enhance the adaptive capacity for the worse weather events. This study is to derive the concept for adapting to these climate changes which can make cities escape from exposure to these climate change impacts and make themselves safer places to live. And it analyzes some European cities and present developing models to implement planning methods. In this study, the concept of the climate adaptive cities will be suggested to prepare the adaptation measures for urban planners, and climate change adaptation models will be presented by analyzing some preliminary cases.

Propeller racing of ocean-going ships with multiple screw propellers (다축선의 프로펠러 레이싱 추정에 관한 연구)

  • Park, Jong-Heon
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.43 no.3
    • /
    • pp.222-231
    • /
    • 2007
  • This paper represents a basic statistical examination on the navigability of ocean-going ship from the point of estimating the time lasting period when propeller racing occurred by using the basic probability theory and the statistics. The propeller racing is one of the most important seakeeping qualities in relation to the safety of the main engine and shafting system. The trend of the racing has been mainly investigated in order to estimate allowable maximum propeller diameter, operation of ocean-going ships, etc.. In those studies, the propeller racing generally and mainly means the situation (propeller exposed) in which the relative motion amplitude between ship hull and wave surface would exceed a depth of point in rotary disk propeller. Therefore, it seems that the magnitude of the amplitude and its exceeding frequency of propeller racing have been examined as a principal subject of study as usual. However, the time during which the amplitude exceeds the depth of point, that is, the propeller exposes in the air, must be also one of most important factor affecting the trend of propeller racing. Then, this paper proposes a new practical method for estimating the time lasting of exposed propeller related to propeller racing in rough-confused seas on the basis of the linear strip theory and the statistics. And, numerical examples of estimating the propeller racing probability are given for four wide ship forms. Finally the usefulness of the proposed method for predicting propeller racing based on the time lasting period is discussed.

Molecular Cloning of Chitinase Genes Family from Serratia marcescens

  • Song, Young-Hwan;Kweon, Oh-Gun
    • Journal of fish pathology
    • /
    • v.6 no.2
    • /
    • pp.103-110
    • /
    • 1993
  • Total genomic DNA library of Serratia marcescens was prepared by inserting Sau3AI partial digesting fragments(above 5 kb) into the dephosphorylated BamHl site of pUC19. In primary screening, two colonies were selected by observing the halo around E. coli transformants grown on the swollen colloidal chitin media. Secondary screening was performed by soaking two colonies with a few drops of 4-methylumbelleliferryl N-acetyl-$\beta$-D-glucocosaminide(4-MuNGlcNAc). As 4-MuNGlcNAc is a specific, fluorogenic substrate for chitinase, the positive clones produce light fluorescence by the exposure under the long wave U.V. light(360 nm). From genomic DNA library derived from pUC19, we have isolated two different chitinase clones, pCH1(11.0Kb) and pCH2(7.5Kb), which show completely different restriction map to each other. The cross-hybridization of pCH1EA and pCH2 have not revealed any hybridization signals to each other.

  • PDF

Realization of High Impedance Surface Characteristics Using a Periodically Transformed Artificial Magnetic Conductor Structure and Reduction Technique of Specific Absorption Rate

  • Lee, Seungwoo;Rhee, Seung-Yeop;Kim, Pan-Yeol;Kim, Nam
    • Journal of electromagnetic engineering and science
    • /
    • v.13 no.2
    • /
    • pp.113-119
    • /
    • 2013
  • We developed a transformed, symmetrical, mushroom-like surface without via holes in cells focused on a 2.4-GHz WLAN band. Each slot in the novel type structure plays a key role in modeling at the desired frequencies. The designed artificial magnetic conductor (AMC) has several advantages, including a small size, a wider bandwidth, a short reflecting distance to the antenna, and easy fabrication because there are no via holes. Overall dimensions of the AMC cell are 21 mm $(Width){\times}21mm$ $(Height){\times}2.6mm$ (Thickness), and the bandwidth is about three times wider (11.7%) compared to that of a conventional AMC (4.0%). For evaluating the performance of the proposed structure, a reflector, which periodically consists of the designed AMC cells, was developed. The antenna with the investigated AMC reflector not only works within a quarter of the wavelength because of the extremely high wave impedance generated by the AMC cells on the surface of the structure but also reduces the specific absorption rate (SAR). Electromagnetic field (EMF) exposure to a human phantom was analyzed by applying the designed reflector to the 2.4-GHz dipole antenna in a tablet PC. The calculated peak SAR averaged over 1 g was 0.125 W/kg when the input power was 1 W and the antenna was located at 20 cm from the human phantom. However, the SAR value was only 0.002 W/kg (i.e., 98.4% blocked) when the designed reflector was inserted in front of the antenna.

A Study on Chinese Students' Clothing Purchase and Wearing Condition (중국 유학생의 의복 구매 및 착용 실태에 관한 연구)

  • Nam, Young-Ran;Kim, Ji-Young;Choi, Hei-Sun
    • Journal of the Korean Society of Costume
    • /
    • v.63 no.6
    • /
    • pp.40-55
    • /
    • 2013
  • The purpose of this study was to find ways to increase sales and enhance of the competitiveness of the Korean fashion brands expanding into the Chinese market by conducting a survey of the Chinese female students in order to gather data regarding their preferences and features so that clothes that are more suitable for Chinese women can be designed. For this study, a survey was conducted to 305 students attending universities or language schools located in the metropolitan areas near Seoul who had exposure to Korean clothes. The study results can be summed up as follows: According to the analysis, the Chinese students preferred comfortable, practical, and casual styles. And the analysis shows that they prefer achromatic monotonous colors rather than vivid colors or splendid and complex patterns. The students felt that Korean clothes reflected the trends very well, and they also showed very high satisfaction with the design. The most common way of gathering information for their clothing purchase was through Internet search and magazine advertisements. The survey showed that the biggest strength of the Korean fashion brands was their ability to reflect the fast changing fashion trends in their designs, and they were very much satisfied with their diverse designs and colors. Among the domestic fashion brands, they prefer domestic SPA brands such as MIXXO, SPAO, and 8IGHT SECONDS.

Effect of Light on the Formation of Non-Basidiocarpous Basidiospores of Ganoderma Lucidum (영지(靈芝)의 비자실체성(非子實體性) 담자포자(擔子胞子)의 형성(形成)에 미치는 광(光)의 영향)

  • Shin, Gwan-Chull;Seo, Geon-Sik
    • The Korean Journal of Mycology
    • /
    • v.17 no.4
    • /
    • pp.189-193
    • /
    • 1989
  • Ganoderma lucidum formed uniquely non-basidiocarpous basidiospore (NBB) from the aerial mycelia on agar media without the normal basidiocarps. Light was necessary for NBB formation. Best sporulation was obtained at the periodic exposure of 16 hour light and 8 hour darkness for more than 8 days. Effective wave length was blue and yellow but non sporulation was induced by near U.V. light. Effective light intensity for NBB bearing appeared to be about 1,000 Lux as white light. Photomorphogenetic responses in Ganoderma lucidum were clearly different among strains of the fungus.

  • PDF

Moderating Effects of Protective Factors on the Relation between Deviant Peer's Influences and Delinquency in Adolescence (청소년기 비행친구의 영향에 대한 보호요인의 조절효과 - 자아존중감, 부모애착 및 지도감독을 중심으로 -)

  • Park, Hyunsun;Lee, Sang-gyun
    • Korean Journal of Social Welfare Studies
    • /
    • no.37
    • /
    • pp.399-427
    • /
    • 2008
  • The purpose of this study is to examine the moderating effects of protective factors on the relations between deviant peer's influences and delinquent behaviors in adolescence. To investigate the moderating effects, simple slope and region of significance test based on multiple linear regression(MLR) model were used. This study used data from wave 1-2(2003-2004) of the Korea Youth Panel Survey(KYPS). Results showed that for female adolescents, self-esteem, parent monitoring, and attachment to parent moderated the link between best friend's deviancy and delinquent behaviors. For male adolescents, however, best friend's deviancy and protective factors didn't show any significant moderating effects. These results help clarify the conditions under which exposure to deviant best friends can influence delinquent behaviors in adolescence. Practice and policy implications as well as further research topic were discussed to aid the search for highly effective preventive and treatment interventions.

Research on the emission of electromagnetic waves in ambulance (구급차량 내 전자파 방출에 관한 조사)

  • Yun, Jong-Geun
    • The Korean Journal of Emergency Medical Services
    • /
    • v.23 no.1
    • /
    • pp.61-69
    • /
    • 2019
  • Purpose: The study aims to provide basic data to enhance the health of paramedics responsible for patient transport and treatment by analyzing the exposure level of paramedics to electromagnetic waves generated by electric devices used in ambulances. Methods: The study measured electromagnetic waves in ambulances in N region from July to December 2018. ME3030B produced by German Gigahertz Solutions was used to measure these waves and the maximum value was selected by moving it slowly in various directions. Each measurement part was selected and the mean value was calculated by repeatedly measuring at 10-minute intervals three times in total: $1^{st}$, $2^{nd}$, and $3^{rd}$ phase. Results: Among the electrical devices installed in the patient room of the ambulance measured at distances of 1 cm or 30 cm, results showed a high level of electric waves at the inverter ($26.25{\pm}39V/m$) and high level of electromagnetic waves ($564.00{\pm}31.75nT$) at the ozone sterilizer. According to measurements toward the front near the driver's seat, results indicated high levels of electric waves ($3.67{\pm}1.15V/m$) and electromagnetic waves ($450.00{\pm}19.52nT$) at the black box hard drive. Conclusion: Electromagnetic waves within the ambulance were stable and not beyond the range that might impact human health. However, in the case of the black box hard drive ($3.67{\pm}1.15V/m$, $450.00{\pm}19.52nT$) located under the passenger seat, it may have a direct effect on the human body and, thus it is necessary to move it to a storage area further away from the paramedics to minimized the impact.

Exploration of shockwaves on polymeric membrane physical properties and performance

  • Lakshmi, D. Shanthana;Saxena, Mayank;Ekambaram, Shivakarthik;Sivaraman, Bhalamurugan
    • Membrane and Water Treatment
    • /
    • v.12 no.1
    • /
    • pp.43-49
    • /
    • 2021
  • The Commercial polymeric membranes like Polysulfone (PSF), Polyvinylidene difluoride (PVDF) and Polyacrylonitrile (PAN) which are an integral part of water purification investigation were chosen for the shockwave (SW) exposure experiment. These membranes were prepared by blending polymer (wt. %) / DMF (solvent) followed by phase-inversion casting technique. Shockwaves are generated by using Reddy Tube lab module (Table-top Shocktube) with range of pressure (1.5, 2.5 and 5 bar). Understanding the changes in membrane before and after shock wave treatment by parameters, i.e., pure water flux (PWF), rejection (%), porosity, surface roughness (AFM), morphology (SEM) and contact angle which can significantly affect the membrane's performance. Flux values PSf membranes shows increase, 465 (pristine) to 524 (1.5wt%) LMH at 50 Psi pressure and similar enhancement was observed at 100Psi (625 to 696 LMH). Porosity also shows improvement from 73.6% to 76.84% for 15wt% PSf membranes. It was observed that membranes made of polymers such as PAN and PSF (of high w/w %) exhibits some resistance against shockwaves impact and are stable compared to other membranes. Shockwave pressure of up to 1.5 bar was sufficient enough to change properties which are crucial for performance. Membranes exposed to a maximum pressure of 5 bar completely scratched the surface and with minimum pressure of 1.5bar is optimum enough to improve the water flux and other parameters. Initial results proved that SW may be suitable alternative route to minimize/control membrane fouling and improve efficiency.

Time Trends and Related Factors of Work-related Low Back Pain among Korean Manufacturing Workers : the third through sixth Korean Working Conditions Survey (제3차 - 6차 근로환경조사를 이용한 우리나라 제조업 근로자의 작업관련 요통유병의 시계열추이 및 관련 요인)

  • Seong-Chan, Heo;Jinwook, Bahk;Seonhee, Yang
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.32 no.4
    • /
    • pp.325-339
    • /
    • 2022
  • Objective: This study was to perform to identify the distribution characteristics and related factors of work-related low back pain among manufacturing workers in Korea. Methods: We analyzed the third(2011) through sixth(2020) Korean Working Conditions Survey. This study examined changes in the prevalence of work-related low back pain among manufacturing workers and related factors, including demographic characteristics and working conditions. Results: The prevalence of work-related low back pain showed a general tendency to increase during the study periods except for the 5th wave. The prevalence of work-related low back pain was higher in women than in men. The prevalence increased with increasing age and decreased with higher educational attainment. This trend was observed in all survey waves. The prevalence ratios for work-related low back pain according to working conditions varied over the survey period. In general, workers with manual jobs, long working hours, and exposure to tired or painful postures showed relatively higher prevalence ratios than did their counterparts. Providing Information on health and safety, perception that work affects health, and experience of presenteeism were identified as influencing factors for work-related low back pain. Although the working environment is improving, work-related back pain is on the rise. A multifaceted study on risk factors for work-related low back pain is needed. Conclusion: Work-related low back pain is a significant factor affecting the working population's quality of life. The prevalence of work-related low back pain showed a tendency to increase during the study periods. A multifaceted study on risk factors for work-related low back pain is needed.