• Title/Summary/Keyword: high reflection

Search Result 1,219, Processing Time 0.028 seconds

Structural and Physical Properties of Reflective Sheets Prepared by Using Glass Beads (유리구슬을 사용하여 제조된 재귀반사시트의 구조 및 재귀반사 특성 연구)

  • Lim, Du-Hyun;Lee, Min-Ho;Heo, Min-Yeong;Ahn, Jou-Hyeon;Park, Jin-Woo;Yu, Ji-Hyun;Kim, Jong-Seon;Ryu, Ho-Suk;Ahn, Hyo-Jun;Kim, Ik-Hwan
    • Elastomers and Composites
    • /
    • v.46 no.4
    • /
    • pp.277-283
    • /
    • 2011
  • In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.

Case studies of shallow marine investigations in Australia with advanced underwater seismic refraction (USR) (최신 수중 탄성파 굴절법(USR)을 이용한 호주의 천부해양탐사 사례연구)

  • Whiteley, Robert J.;Stewart, Simon B.
    • Geophysics and Geophysical Exploration
    • /
    • v.11 no.1
    • /
    • pp.34-40
    • /
    • 2008
  • Underwater seismic refraction with advanced interpretation approaches makes important contributions to shallow marine exploration and geotechnical investigations in Australia's coastal areas. A series of case studies are presented to demonstrate the recent applications of continuous and static USR methods to river crossing and port infrastructure projects at various sites around Australia. In Sydney, static underwater seismic refraction (USR) with bottom-placed receivers and borehole seismic imaging assisted the development of improved geotechnical models that reduced construction risk for a tunnel crossing of the Lane Cove River. In Melbourne, combining conventional boomer reflection and continuous USR with near-bottom sources and receivers improved the definition of a buried, variably weathered basalt flow and assisted dredging assessment for navigation channel upgrades at Geelong Ports. Sand quality assessment with continuous USR and widely spaced borehole information assisted commercial decisions on available sand resources for the reclamation phase of development at the Port of Brisbane. Buried reefs and indurated layers occur in Australian coastal sediments with the characteristics of laterally limited, high velocity, cap layers within lower velocity materials. If these features are not recognised then significant error in depth determination to deeper refractors can occur. Application of advanced refraction inversion using wavefront eikonal tomography to continuous USR data obtained along the route of a proposed offshore pipeline near Fremantle allowed these layers and the underlying bedrock refractor to be accurately imaged. Static USR and the same interpretation approach was used to image the drowned granitic regolith beneath sediments and indurated layers in the northern area of Western Australia at a proposed new berthing site where deep piling was required. This allowed preferred piling sites to be identified, reducing overall pile lengths. USR can be expected to find increased application to shallow marine exploration and geotechnical investigations in Australia's coastal areas as economic growth continues and improved interpretation methods are developed.

Middle school Home Economics teachers' perception and actual performance of self-supervision at school related to Home Economics (중학교 가정과 교사의 교과 관련 교내 자율장학에 대한 인식과 실태)

  • Go, Mi-Young;Chae, Jung-Hyun
    • Journal of Korean Home Economics Education Association
    • /
    • v.22 no.4
    • /
    • pp.91-107
    • /
    • 2010
  • The purpose of this study was to investigate what middle school Home Economics(HE) teachers perceive, practice and need for self-supervision at school related to HE. Questionnaires were sent by E-mail and 150 were collected. Descriptive statistics including frequency, percentage, average, standard deviation, t-test and ANOVA analysis were reported using SPSS/win 10.1. The results of this research were as follows: First, middle school HE teachers perceived that self-supervision at school was essential since it promoted self reflection of teachers themselves and improved professional skills. Furthermore, peer-coaching was highly preferred. Second, negative responses to the supervision of principal, vice-principal, and peer teachers overwhelmed positive answers. Information exchange among peer teachers was frequent, yet, approximately 22.6% of middle school HE teachers were still avoiding sharing information process for several reasons. About half of the teachers answered that all teachers needed to participate in this process. Third, they pointed out that self-supervision at school was not implemented well because of the lack of time due to the heavy work load, negative and passive attitude for the improvement of teaching-learning activities, administration-centered supervision that did not reflect teachers' opinion, and shortage of economical, and environmental support.. HE teachers perceived that peer teachers who were doing good practices were most helpful for the supervision. Also, they preferred self-evaluation at the end of the self-supervision at school. Forth, to improve self-supervision at school, there were very high demands for reduction of administrative work, additional time, fundamental philosophy toward HE education. Fifth, the purpose and detailed plans of self-supervision were recognized as the results that were democratically derived by the HE teachers. Sixth, class inspection and informal inspection were operated once in a year, and self-training was rarely operated. Peer coaching and self-coaching were operated occasionally. Self-coaching and peer coaching were reported as the most helpful types of supervision. In addition, HE teachers answered that supervision was helpful to teaching method followed by contents, evaluation, and philosophy of education.

  • PDF

Development of a New Terrain Type Classification to be used in Highway Design (도로설계 적정화를 위한 새로운 지형구분에 관한 연구)

  • Kim, Sang-Youp;Choi, Jai-Sung;Lee, Seung-Yong;Han, Hyung-Gwan
    • International Journal of Highway Engineering
    • /
    • v.8 no.4 s.30
    • /
    • pp.49-62
    • /
    • 2006
  • The republic of korea has put a great emphasis on the role of the road as widening a social infra-structural facility. Thus, vast amount of money has been invested on the road establishment. As a result, there has been fruitful outcomes in establishing the road system of the nation especially for the flat road with ease. However, in order to have more systematic and sustainable road system, we should turn our attention to more painful and high-cost regions such as mountainous districts and those are to be developed effectively. The configuration of the road is an important factor to be considered in making a decision for the road planning. Nevertheless, current road planning criterion has no such clarified and objective judging standard for figuring the configuration of the road out and, as a result, speed planning can be decided incorrectly. our research has acknowledged the necessity of estimating the configuration of the road and aimed to make it organized and sorted according to the height, slope, and the vehicle's speed. The results are as follows. First, our research made use of GIS data and classified the road into 9 different areas according to the height and the slope. Also, road classification being matched to the data of vehicle's speed, it has been shown that those characteristics of different areas have made an influence on vehicle's speed. Secondly, based on the results of the similarity between geographical classification and, vehicle's speed of sorted groups according to the height and the slope, conclusively we have classified as flat, rolling region and mountain. Since our research has made use of vehicle's speed for National Highway, it is not applicable to different functional highways. However, for the highway to be established hereafter, it can be a standard for reflection geographical characteristics.

  • PDF

Spaciotemporal Distributions of PM10 Concentration and Their Correlation with Local Temperature Changes : a Case Study of Busan Metropolitan City (PM10 농도의 시공간적 분포 특징과 국지적 기온 변화 간의 상관관계: 부산광역시 사례 분석)

  • Park, Sunyurp
    • Journal of the Korean association of regional geographers
    • /
    • v.23 no.1
    • /
    • pp.151-167
    • /
    • 2017
  • The main objective of this study was to investigate the climatic impact of $PM_{10}$ concentration on the temperature change pattern in Busan Metropolitan City(BMC), Korea during 2001~2015. Mean $PM_{10}$ concentration of BMC has gradually declined over the past 15 years. While the highest $PM_{10}$ concentration was observed in spring followed by winter, summer, and fall on average, the seasonal variations of $PM_{10}$ concentration differed from place to place within the city. Frequency analysis showed that the most frequently observed $PM_{10}$ concentration ranged from $20{\mu}g/m^3$ to $60{\mu}g/m^3$, which accounted for 64.6% of all daily observations. Overall, the west-high and east-low pattern of $PM_{10}$ concentration was relatively strong during the winter when the effect of yellow-dust events on the air quality was weak. Comparative analyses between $PM_{10}$ concentration and monthly temperature slope derived from generalized temperature curves indicated that the decreasing trend of $PM_{10}$ concentration was associated with increases of annual temperature range, and $PM_{10}$ concentration had a negative relationship with the temperature slope of warming months. Overall, $PM_{10}$ concentration had a weak correlation with the annual mean temperature, but it had a significant, positive correlation with the winter season, which had a dominant influence on the annual mean temperature. In terms of energy budget, it has been known that the change in $PM_{10}$ concentration contributes to the warming or cooling effect by affecting the radiative forcing due to the reflection and absorption of radiant energy. The correlation between $PM_{10}$ concentration and temperature changes in the study area was not seasonally and spatially consistent, and its significance was statistically limited partly due to the number of observations and the lack of potential socioeconomic factors relevant to urban air quality.

  • PDF

Study on Features of Software Cyborg in the Virtual Game -PS4 ocusing Game- (가상게임에 나타나는 소프트웨어 사이보그특징에 대한 고찰 -PS4 <언틸던> 게임을 중심으로-)

  • Kim, Dae-Woo
    • Cartoon and Animation Studies
    • /
    • s.41
    • /
    • pp.279-306
    • /
    • 2015
  • This paper is a study of the changing nature of software for virtual Cyborg self and the virtual body that occur in the game from a philosophical point of view. Looking broadly, the cyborg concept refers to the combination of man and machine. Specifically, there is a hardware cyborg organism to combine human and restoration of machine In addition, there is software cyborg by electronic the human brain of converting a virtual body. Virtual games are cases software-Cyborg applied. In the game , There seems to have characteristics of virtual body and ego that different from general cyborg meaning. To analyze the features, I applied the concept of software-cyborg of Hans morabek and the multiple selves in cyberspace properties of Kim Sun-Hee. generally, software cyborg cloning the brain type tended to invalidate the body due to the nature of the virtual world. But If you look at third-person's view and the game character that made from real actors, it is pursuing the realism of photographic images and it stressed the need for a virtual body in order to maintain the psychological identity of the player. And, The game player crosses the eight characters to choose while completing the mission. This is a big role in the reality ego leads to the desired final ending with the selection and experience to be experienced as self-replication to multiple. These cyber multi-ego looks for an active and positive features compared to the multi-ego in the real world and highlights the advantages of the software cyborg. Game The characteristics of the final result varies depending on the selection of the player. The life and death of a friend is determined by the relationship between the characters friendship. In this case, the virtual self is empirically through trial and error, moral, and try to select the desired setting the standard for intuitive and self own choice. Also It can be fused to the knowledge of multiple selves as one step is formed by a high spiritual introspection. This process is a positive interpretation of the world and their own forms of mental reflection through self-overcoming human, Nietzsche is said that the process is Wibeomenswi.

Comparison of Student Satisfaction with Foodservice of Middle School by Place for Meal Service in Busan Area (배식장소에 따른 부산 일부지역 중학생의 급식만족도 평가)

  • Lee, Kyung-A;Lyu, Eun-Soon
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.34 no.2
    • /
    • pp.209-218
    • /
    • 2005
  • The purpose of this study was to evaluate the students' satisfaction with the Quality of middle school foodservice in Busan area. For purpose, Questionnaires were distributed to 788 students in 8 middle schools (four schools for classroom service, four schools for restaurant service). The average scores were -1.13 for gap of meal, -1.68 for sanitation, -1.19 for menu, -1.63 for attitude of foodservice staffs, and -0.89 for rapidity and exactness of service. The whole students assessed the important and performance of school food service 4.20/5.00 and 2.99/5.00. The restaurant service had significantly (p<0.01) higher average scores performance of meal, sanitation, and rapidity and exactness of service than those of the class room service. The Importance-Performance Analysis (IPA) gride, high importance and low performance (focus here) were cleanliness of dish, cleanliness restoration area, rapid treatment about complaints, reflection students' opinions, and listening to students' opinions in the classroom service and the restaurant service, but the Quality vs. price of meal, sanitation of meal, and dessert supply were included in focus here part in the classroom service.

Static and Dynamic Analysis for Railway Tunnel according to Filling Materials for overbroken tunnel bottom (철도터널 하부 여굴처리 방법에 대한 정적 및 동적 안정성 검토)

  • Seo, Jae-Won;Cho, Kook-Hwan
    • Journal of the Korean Society for Railway
    • /
    • v.20 no.5
    • /
    • pp.668-682
    • /
    • 2017
  • Alignments of railways recently constructed in Korea have been straightened due to the advent of high-speed rail, which means increasing the numbers of tunnels and bridges. Overbreak during tunnel construction may be unavoidable, and is very influential on overall stability. Over-excavation in tunneling is also one of the most important factors in construction costs. Overbreak problems around crown areas have decreased with improvements of excavation methods, but overbreak problems around bottom areas have not decreased because those areas are not very influential on tunnel stability compared with crown areas. The filling costs of 10 cm thickness of overbreak at the bottom of a tunnel are covered under construction costs by Korea Railway Authority regulations, but filling costs for more than the covered thickness are considered losses of construction cost. The filling material for overbreak bottoms of tunnels should be concrete, but concrete and mixed granular materials with fractured rock are also used for some sites. Tunnels in which granular materials with fractured rock are used may have a discontinuous section under the concrete slab track. The discontinuous section influences the propagation of waves generated from train operation. When the bottom of a tunnel is filled with only concrete material, the bottom of the tunnel can be considered as a continuous section, in which the waves generated from a train may propagate without reflection waves. However, a discontinuous section filled with mixed granular materials may reflect waves, which can cause resonance of vibration. The filled materials and vibration propagation characteristics are studied in this research. Tunnel bottom filling materials that have ratios of granular material to concrete of 5.0 %, 11.5 %, and 18.0 % are investigated. Samples were made and tested to determine their material properties. Static numerical analyses were performed using the FEM program under train operation load; test results were found to satisfy the stability requirements. However, dynamic analysis results show that some mixed ratios may generate resonance vibration from train operation at certain speeds.

The Effect of Directivity of Antenna for the Evaluation of Abnormal Area Using Ground Penetrating Radar (지하투과레이더를 이용한 이상구간 평가 시 안테나 지향성의 영향)

  • Kang, Seonghun;Lee, Jong-Sub;Lee, Sung Jin;Park, Young-Kon;Hong, Won-Taek
    • Journal of the Korean Geotechnical Society
    • /
    • v.33 no.11
    • /
    • pp.21-34
    • /
    • 2017
  • The ground penetrating radar (GPR) signal can be measured with different amplitudes according to the directivity, so the directivity of the antenna should be considered. The objective of this study is to investigate the directivity of antenna by analyzing the reflection characteristics of electromagnetic waves radiated from the antenna, and to evaluate effective range of angle that can inspect an abnormal area according to the directivity of antenna. For the measurement of the directivity, a circular metal bar is used as reflector and the signals are measured by changing the angle and the distance between reflector and antenna in the E- and H-plane. The boundary distance between the near field and the far field is determined by analyzing the amplitudes of reflected signals, and two points with different distances from each of near and far fields are designated to analyze radiation patterns in near and far fields. As a result of radiation pattern measurement, in the near field, minor lobes are observed at angle section at more than $50^{\circ}$ in both E- and H-plane. Therefore, antenna has the directivity for the direction of main lobe and minor lobes in near field. In the far field, antenna has the directivity for a single direction of main lobe because minor lobes are not observed. The amplitude of the signal reflected from the near field is unstable, but it can be distinguished from noise. Therefore, in the near field, the ground anomaly can be detected with high reliability. On the other hand, the amplitude of the signal reflected from the far field is stable, but it is hard to distinguish between reflected signal and noise because of the excessive loss of electromagnetic wave. The analyses of directivity in the near and the far fields performed in this study may be effectively used to improve the reliability of the analyses of abnormal area.

Analysis of Consumer Attitudes to Washed Fresh Ginseng (세척 및 시판 수삼 이용실태와 소비자 인식도 분석)

  • Cho, Sun-Duk;Chang, Min-Sun;Kim, Dong-Man;Kim, Gun-Hee
    • Food Science and Preservation
    • /
    • v.16 no.4
    • /
    • pp.579-589
    • /
    • 2009
  • We focused on the condition of washed, fresh ginseng in the market and analyzed consumer attitudes to the product to improve the consumption of fresh ginseng. A preference for fresh ginseng was high among every age class, and was particularly notable in older individuals. Fresh ginseng was usually eaten as ginseng chicken soup, mostly in summer and winter, and as a valuable health food, rather than because of desirable qualities of taste or smell. A total of 66.5% of those surveyed reported that they had purchased fresh ginseng, mostly from big discount stores. Such stores were preferred as outlets owing to a reputation for quality and shopper convenience (the stores were located near interviewees' homes). More than 70% of purchasers emphasized that they chose to purchase in department stores and traditional markets owing to the reputation for quality of such sources. Most consumers considered quality to be a prime element in purchase decisions. A total of 32.9% of those surveyed had bought washed fresh ginseng to give as a gift to a friend. Of those surveyed, 67.1% had never bought washed fresh ginseng. The following reasons were proposed to explain the preference for purchase of ginseng with attached soil. Most consumers (40.2%) thought the soil was a reflection of quality. Those who preferred washed fresh ginseng considered that the material was hygienic and convenient to store. When questioned about their intention to buy washed fresh ginseng, 55.0% of consumers replied in the affirmative and 17.1% in the negative. When consumers were asked whether they would be willing to pay an additional charge for the washing and packing of fresh ginseng, 58.8% answered in the affirmative.