• Title/Summary/Keyword: light-tree

Search Result 349, Processing Time 0.024 seconds

Collision Reduction Using Modified Q-Algorithm with Moving Readers in LED-ID System

  • Huynh, Vu Van;Le, Nam-Tuan;Choi, Sun-Woong;Jang, Yeong-Min
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37 no.5A
    • /
    • pp.358-366
    • /
    • 2012
  • LED-ID (Light Emitting Diode - Identification) is one of the key technologies for identification, data transmission, and illumination simultaneously. This is the new paradigm in the identification technology environment. There are many issues are still now challenging to achieve high performance in LED-ID system. Collision issue is one of them. Actually this is the most significant issue in all identification system. LED-ID system also suffers from collision problem. In our system, collision occurs when two or more readers transmit data to tag at the same time or vice versa. There are many anti-collision protocols to resolve this problem; such as: Slotted ALOHA, Basic Frame Slotted ALOHA, Query Tree, Tree Splitting, and Q-Algorithm etc. In this paper, we propose modified Q-Algorithm to resolve collision at tag. The proposed protocol is based on Q-Algorithm and used the information of arrived readers to a tag from neighbor. The information includes transmitting slot number of readers and the number of readers that can be arrived in next slot. Our proposed protocol can reduce the numbers of collision slot and the successful time to identify all readers. In this paper our simulation and theoretical results are presented.

Diseases of Tea Trees II. White Scab of Tea Tree Caused by Sphaceloma theae (차나무의 병해 II. Sphaceloma theae에 의한 차 흰별무늬병)

  • 박서기
    • Korean Journal Plant Pathology
    • /
    • v.11 no.4
    • /
    • pp.383-385
    • /
    • 1995
  • Occurrence of white scab of tea (CAmellia sinensis) showing numerous, small, circular, reddish or yellowish brown spots on young tea leaves was observed at a tea plantation of Boseung, Chonnam, from May to June in 1992-1994. At the late growth stages, the center of the spot became light gray. The causal fungus of the white scab was identified as Sphaceloma theae Kurosawa. Symptoms were produced 5∼6 days after inoculation by the artificial inoculation of s. theae conidia, which was similar to those on naturally infected leaves.

  • PDF

A Comparison of Photosynthetic Characteristics of Three Ligularia species Under-tree Cultivation (임간재배지에서 세 종 곰취(Ligularia)속 식물의 광합성특성 비교)

  • Kim, Gab-Tae
    • Korean Journal of Plant Resources
    • /
    • v.21 no.5
    • /
    • pp.357-361
    • /
    • 2008
  • The photosynthetic characteristics of three Ligularia species, L. fischeri, L. fischeri var. spiciformis and L. stenocephala under-tree cultivated in Dunnae-myeon, Hoengsung-gun were measured and compared. Total mean photosynthetic rate increased with increasing the light intensity up to 2,000 PPFD. Mean photosynthetic rate of L. fischeri increased to maximum value of $21.1{\mu}mol\;CO_{2}m^{-2}s^{-1}$ with increasing the light intensity up to 1,600 PPFD, but it was decreased at 2,000 PPFD. The highest photosynthetic rate was shown in L. fischeri var. spiciformis, followed by L. fischeri, and L. stenocephala. was the highest $27.39{\mu}mol\;CO_{2}m^{-2}s^{-1}$ among three species, followed by that of The differences in photosynthetic rates were significantly different among the species each measuring date. L. fischeri var. spiciformis was more adaptive species at the low elevated under-tree cultivated sites, such as, Sanchemaeul Dunnae-myeon Hoeyngseung-gun than L. fischeri and L. stenocephala.

The Effect of Urban Trees on Residential Solar Energy Potential (도심 수목이 분산형 주거 태양광에너지 잠재량에 미치는 영향)

  • Ko, Yekang
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.42 no.1
    • /
    • pp.41-49
    • /
    • 2014
  • This study spatially assesses the impact of trees on residential rooftop solar energy potential using urban three-dimensional models derived from Light Detection and Ranging(LiDAR) data in San Francisco, California. In recent years on-site solar energy generation in cities has become an essential agenda in municipal climate action plans. However, it can be limited by neighboring environments such as shade from topography, buildings and trees. Of all these effects, the impact of trees on rooftop photovoltaics(PVs) requires careful attention because improper situation of solar panels without considering trees can result in inefficient solar energy generation, tree removal, and/or increasing building energy demand and urban heat island effect. Using ArcMap 9.3.1, we calculated the incoming annual solar radiation on individual rooftops in San Francisco and the reduced insolation affected by trees. Furthermore, we performed a multiple regression analysis to see what attributes of trees in a neighborhood(tree density, tree heights, and the variance of tree heights) affect rooftop insolation. The result shows that annual total residential rooftops insolation in San Francisco is 18,326,671 MWh and annual total light-loss reduction caused by trees is 326,406 MWh, which is about 1.78%. The annual insolation shows a wide range of values from $34.4kWh/m^2/year$ to $1,348.4kWh/m^2/year$. The result spatially maps the locations that show the various levels of impact from trees. The result from multiple regression shows that tree density, average tree heights and the variation of tree heights in a neighborhood have statistically significant effects on the rooftop solar potential. The results can be linked to municipal energy planning in order to manage potential conflicts as cities with low to medium population density begin implementing on-site solar energy generation. Rooftop solar energy generation makes the best contribution towards achieving sustainability when PVs are optimally located while pursuing the preservation of urban trees.

Automatic Extraction of Tree Information in Forest Areas Using Local Maxima Based on Aerial LiDAR (항공 LiDAR 기반 Local Maxima를 이용한 산림지역 수목정보 추출 자동화)

  • In-Ha Choi;Sang-Kwan Nam;Seung-Yub Kim;Dong-Gook Lee
    • Korean Journal of Remote Sensing
    • /
    • v.39 no.5_4
    • /
    • pp.1155-1164
    • /
    • 2023
  • Currently, the National Forest Inventory (NFI) collects tree information by human, so the range and time of the survey are limited. Research is actively being conducted to extract tree information from a large area using aerial Light Detection And Ranging (LiDAR) and aerial photographs, but it does not reflect the characteristics of forest areas in Korea because it is conducted in areas with wide tree spacing or evenly spaced trees. Therefore, this study proposed a methodology for generating Digital Surface Model (DSM), Digital Elevation Model (DEM), and Canopy Height Model (CHM) images using aerial LiDAR, extracting the tree height through the local Maxima, and calculating the Diameter at Breath Height (DBH) through the DBH-tree height formula. The detection accuracy of trees extracted through the proposed methodology was 88.46%, 86.14%, and 84.31%, respectively, and the Root Mean Squared Error (RMSE) of DBH calculated based on the tree height formula was around 5cm, confirming the possibility of using the proposed methodology. It is believed that if standardized research on various types of forests is conducted in the future, the scope of automation application of the manual national forest resource survey can be expanded.

Improvement of Light Fastness of Berberine Colorant by Natural Antioxidants

  • Kim, Tae-Kyeong;Kim, Eun-Kyung;Jeong, Jong-Seok
    • Textile Coloration and Finishing
    • /
    • v.19 no.2
    • /
    • pp.1-6
    • /
    • 2007
  • In order to improve the light fastness of a natural colorant berberine, several natural antioxidants such as gallic acid, L-ascorbic acid, and ${\alpha}-tocopherol$ were applied by aftertreatment method. Even though the increase in light fastness of berberine colorant was not substantial, L-ascorbic acid was the most effective. It was considered that this improvement of the light fastness was due to high antioxidation action of L-ascorbic acid to colorant, which led very highly excited species of the colorant formed by photo-energy to return to the original stable state without being decomposed.

Light-Ontology Classification for Efficient Object Detection using a Hierarchical Tree Structure (효과적인 객체 검출을 위한 계층적 트리 구조를 이용한 조명 온톨로지 분류)

  • Kang, Sung-Kwan;Lee, Jung-Hyun
    • Journal of Digital Convergence
    • /
    • v.10 no.10
    • /
    • pp.215-220
    • /
    • 2012
  • This paper proposes a ontology of tree structure approach for adaptive object recognition in a situation-variant environment. In this paper, we introduce a new concept, ontology of tree structure ontology, for context sensitivity, as we found that many developed systems work in a context-invariant environment. Due to the effects of illumination on a supreme obstinate designing context-sensitive recognition system, we have focused on designing such a context-variant system using ontology of tree structure. Ontology can be defined as an explicit specification of conceptualization of a domain typically captured in an abstract model of how people think about things in the domain. People produce ontologies to understand and explain underlying principles and environmental factors. In this research, we have proposed context ontology, context modeling, context adaptation, and context categorization to design ontology of tree structure based on illumination criteria. After selecting the proper light-ontology domain, we benefit from selecting a set of actions that produces better performance on that domain. We have carried out extensive experiments on these concepts in the area of object recognition in a dynamic changing environment, and we have achieved enormous success, which will enable us to proceed on our basic concepts.

An EIBS Algorithm for Wireless Sensor Network with Life Time Prolongation (수명 연장 기능의 무선 센서 네트워크용 EIBS 알고리즘)

  • Bae, Shi-Kyu
    • Journal of the Korea Society of Computer and Information
    • /
    • v.19 no.9
    • /
    • pp.65-73
    • /
    • 2014
  • Since Time synchronization is also critical in Wireless Sensor Networks (WSN) like other networks, a time synchronization protocol for WSN called IBS(Indirect-Broadcast Synchronization) has been already proposed in 2012. As IBS operates in cluster tree topology, network lifetime may be mainly shortened by cluster head node[s], which usually consumes more power than cluster member (i.e. non-cluster head) nodes. In this paper, I propose enhanced version of IBS (called EIBS) which saves overall energy and prolongs network lifetime by re-constructing partial cluster tree locally. Compared with other tree construction approaches, this tree reconstruction algorithm is not only simpler, but also more efficient in the light of overall power consumption and network lifetime.

Dyeing of Wool and Nylon Fabrics with Chinese Scholar Tree Extract (괴화 추출물에 의한 모와 나일론직물의 염색성)

  • 배정숙;허만우
    • Journal of the Korean Home Economics Association
    • /
    • v.41 no.2
    • /
    • pp.107-121
    • /
    • 2003
  • This study was discussed the dyeing of wool and nylon fabrics with Chinese Scholar Tree extract. The extracts of Chinese Scholar Tree was prepared in the condition of heating at $95{\pm}5C$, for 1 hour and cooling to 40C. And then the extracts of color matter treate with vacuum concentration at $60{\pm}2^{\circ}C$, 30mmHg and dried with spray dryer. The dyeing of wool and nylon fabric in this experiment was also employed the mordant dyeing method such as pre-mordant, post-mordant and simultaneous mordant method. The mordanting agents used in this study were as followings ; aluminium potassium sulfate, copper(II) acetate monohydrate, chromium potassium sulfate$.$$7H_2O$, Tin(II) chloride dihydrate, iron(II)sulfate $7H_2O$. For an evaluation of the dyeing property of the mordanting agents, the pre-mordant method, the repeat dyeing and the fastness of the light, dry cleaning, washing and rubbing measured respectively. From the results of the dye absorption, the optimum dyeing condition of the wool and nylon fabrics with Chinese Scholar Tree extract is at 80C dyeing temperature for 60 minutes. The optimum concentration of mordanting agent is Al, Cr, Sn 1%, Fe, Cu 2% solution. In general, the fastness property of the dyed wool and nylon fabrics had a comparatively high grade.

LIGHT-REGULATED LEAF MOVEMENT AND SIGNAL TRANSDUCTION IN NYCTINASTIC PLANTS

  • Kim, Hak-Yong
    • Journal of Photoscience
    • /
    • v.4 no.1
    • /
    • pp.23-30
    • /
    • 1997
  • Leaf movements in nyctinastic plants are produced by changes in the turgor of extensor and flexor cells, collectively called motor cells, in opposing regions of the leaf movement organ, the pulvinus. In Samanea saman, a tropical tree of the legume family, extensor cells shrink and flexor cells swell to bend the pulvinus and fold the leaf at night, whereas extensor cells swell and flexor cells shrink to straighten the pulvinus and extend the leaf in the daytime. These changes are caused by ion fluxes primarily of potassium and chloride, across the plasma membrane of the motor cells. These ion fluxes are regulated by exogenous light signals and an endogenous biolgical clock. Inward-directed K$^+$ channels are closed in extensor and open in flexor cells in the dark period, while these channels are open in extensor and closed in flexor cells in the light period. Blue light opens the closed K$^+$ channels in extensor and closes the open them in flexor cells during darkness. Illumination of red light followed by darkness induces to open the closed K$^+$ channels in flexor and to close the open K$^+$ channels in extensor cells in the light. The dynamics of K$^+$ channels in motor cells that are controlled by light signals are consistent with the behavior of the pulvini in intact plants. Therefore, these cell types are an attractive model system to elucidate regulations of ion transports and their signal transduction pathways in plants. This review is focused on light-controlled ion movements and regulatory mechanisms involved in phosphoinositide signaling in leaf movements in nyctinastic plants.

  • PDF