• Title/Summary/Keyword: Forestry Engineering

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Existing Forms of Heavy Metals in the Vicinity of a Smelter (제련소 주변토양 중금속 존재형태)

  • Woo, Sang-Duck;Kim, Geon-Ha;Kim, Young-Jin;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.15 no.5
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    • pp.16-22
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    • 2010
  • Heavy metals in soils exist in various forms dependent upon surrounding conditions. As the Janghang smelter area is of concern for its high elevated heavy metal concentrations, Korean government decided to remediate the area. Main objectives of this research were; to analyze heavy metal concentrations and their existing forms in the vicinity of the smelter; and to understand differences made by analysis techniques of heavy metals. Top soils of rice field, crop field, bare field, and forestry in the area were sampled and analyzed for their physicochemical characteristics. Concentrations of Cu, Cd, Pb, and As were analyzed with two pretreatment techniques adopted using 0.1 N HCl and aqua regia. To analyze existing forms of heavy metals, Tessier's schemes for sequential extraction technique were adopted. Exchangeable fraction and carbonate bound fraction of heavy metals may pose potential threat to environment and were in the order of Pb > As > Cu > Cd. If assessing mobile fraction of heavy metals by land uses, the order was forestry > bare land > crop field > rice field. When analyzed using Tessier's scheme, high ratio of residual fractions to total arsenic concentration should be considered for remediation design of the area.

The use of the semi-empirical method to establish a damping model for tire-soil system

  • Cuong, Do Minh;Ngoc, Nguyen Thi;Ran, Ma;Sihong, Zhu
    • Coupled systems mechanics
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    • v.7 no.4
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    • pp.395-406
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    • 2018
  • This paper proposes a linear damping model of tire-soil system using semi-empirical method. A test rig was designed and developed to measure the vertical equivalent linear damping ratio of tire only and tire-soil system using Free-Vibration Logarithmic Decay Method. The test was performed with two kinds of tractor tires using a combination of five inflation pressure levels, two soil depths and four soil moisture contents in the paddy soil. The results revealed that the linear damping ratio of tires increased with decreasing tire inflation pressure; the linear damping ratio of tire-soil system also increased with decreasing tire inflation pressure and increased with the increasing soil depth (observed at 80 and 120 mm). It also increased with a relative increase of soil moisture contents (observed at 37.9%, 48.8%, 66.7% and 77.4%). The results also indicated that the damping ratio of tire-soil system was higher than that of tire only. A linear damping model of tire-soil system is proposed as a damping model in parallel which is established based on experimental results and vibration theory. This model will have a great significance in study of tractor vibration.

Improved marine predators algorithm for feature selection and SVM optimization

  • Jia, Heming;Sun, Kangjian;Li, Yao;Cao, Ning
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.4
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    • pp.1128-1145
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    • 2022
  • Owing to the rapid development of information science, data analysis based on machine learning has become an interdisciplinary and strategic area. Marine predators algorithm (MPA) is a novel metaheuristic algorithm inspired by the foraging strategies of marine organisms. Considering the randomness of these strategies, an improved algorithm called co-evolutionary cultural mechanism-based marine predators algorithm (CECMPA) is proposed. Through this mechanism, search agents in different spaces can share knowledge and experience to improve the performance of the native algorithm. More specifically, CECMPA has a higher probability of avoiding local optimum and can search the global optimum quickly. In this paper, it is the first to use CECMPA to perform feature subset selection and optimize hyperparameters in support vector machine (SVM) simultaneously. For performance evaluation the proposed method, it is tested on twelve datasets from the university of California Irvine (UCI) repository. Moreover, the coronavirus disease 2019 (COVID-19) can be a real-world application and is spreading in many countries. CECMPA is also applied to a COVID-19 dataset. The experimental results and statistical analysis demonstrate that CECMPA is superior to other compared methods in the literature in terms of several evaluation metrics. The proposed method has strong competitive abilities and promising prospects.

Current Status of EM (Effective Microorganisms) Utilization (유용미생물 (EM, Effective Microorganisms)의 활용 현황)

  • Moon, Yun-Hee;Lee, Kwang-Bae;Kim, Young-Jun;Koo, Yoon-Mo
    • KSBB Journal
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    • v.26 no.5
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    • pp.365-373
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    • 2011
  • Effective Microorganisms (EM), a fermented medium developed by Professor Higa at the University of the Ryukyus, is a mixed culture containing dozens of microorganisms which are beneficial to nature including people, animals, plants and many microbial species in environment. EM is known to contain more than 80 kinds of anaerobic or aerobic microbes including photosynthetic bacteria, lactic acid bacteria, yeast, actinomycetes, fungi and so on, with yeast, lactic acid bacteria and photosynthetic bacteria as the main species of EM. Antioxidant effect generated by the concert of complex coexistence and coprosperity among these microbes is considered to be the main source of EM benefits. Currently, EM is earning an increasing attention with applications in agriculture, forestry, animal husbandry, fisheries, environment and medicine among others. At the same time, however, a quantitative interpretation of EM system based on a mixed culture model needs efforts from biochemical engineers for efficient production and further promotion of EM. In this paper, we describe the functions of major microbes in EM and current researches and applications of EM in agriculture, forestry, animal husbandry, fisheries, environment and medicine.

Passive Ranging Based on Planar Homography in a Monocular Vision System

  • Wu, Xin-mei;Guan, Fang-li;Xu, Ai-jun
    • Journal of Information Processing Systems
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    • v.16 no.1
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    • pp.155-170
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    • 2020
  • Passive ranging is a critical part of machine vision measurement. Most of passive ranging methods based on machine vision use binocular technology which need strict hardware conditions and lack of universality. To measure the distance of an object placed on horizontal plane, we present a passive ranging method based on monocular vision system by smartphone. Experimental results show that given the same abscissas, the ordinatesis of the image points linearly related to their actual imaging angles. According to this principle, we first establish a depth extraction model by assuming a linear function and substituting the actual imaging angles and ordinates of the special conjugate points into the linear function. The vertical distance of the target object to the optical axis is then calculated according to imaging principle of camera, and the passive ranging can be derived by depth and vertical distance to the optical axis of target object. Experimental results show that ranging by this method has a higher accuracy compare with others based on binocular vision system. The mean relative error of the depth measurement is 0.937% when the distance is within 3 m. When it is 3-10 m, the mean relative error is 1.71%. Compared with other methods based on monocular vision system, the method does not need to calibrate before ranging and avoids the error caused by data fitting.

The Research on Herb and Its Allocation Form in Landscape

  • Zhang, Li-Qin;Piao, Yong-Ji;Shen, Ning;Cho, Tae-Dong
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.131-138
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    • 2013
  • In order to provide a scientific foundation for herb application in landscape, the photographs were taken from the herb landscape in urban green space and sightseeing garden. The questionnaire-based survey was also applied to analyze the cognitive situation of herb. Most investigators love herb, but have a low level of herb; Interviewees' consideration of herb function lie in ornamental, healthcare and medical treatment; The bulk of the visitors think herb landscape is insufficient; Investigators' preferences for herb application forms are landscape edging and combining with stone. We also probe into the optimum allocation form combining herb with landscape elements. When we combine herb with landscape water or landscape architecture, artistic conception and reasonable plant allocation should be considered; When we combine herb with landscape path or garden ornament, reasonable plant disposition and appearance and practical collocation should be thought over; When we combine herb with flower-border, richly colored landscape and reasonable plant allocation should be deliberated on.

A Study on Tourist Psychological Capacity of Scenic and Historic Area and Its Influencing Factors - A Case Study of Mount Tai Scenic Spot

  • Cao, Lin-Sen;Piao, Yong-Ji;Zhang, Rui;Cho, Tae-Dong
    • Journal of Environmental Science International
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    • v.23 no.5
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    • pp.755-761
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    • 2014
  • Tourist Psychological Capacity (TPC) is an important issue of the Tourism Capacity research. We gained the tourist satisfaction through the questionnaire investigation in Mount Tai Scenic Area and obtained the tourist satisfaction function using SPSS17.0 regression analysis method. Then we got the best psychological capacity of tourists with the Marginal Satisfaction Method. Finally we verified the influencing factors on TPC. The study found that the best TPC of Mount Tai Scenic Area is 10323 persons; Female shows lower TPC than male. Moreover, female satisfaction is more easily influenced by visitors' number increasing than male satisfaction; TPC plays negative correlation with the increasing of age. Teenagers and adults have no much difference in TPC, but the seniors present a relatively lower TPC than other; The higher education, the smaller TPC.

A Chinese Wood Species, Hongmu and Its Characteristics for Identification

  • Fu, Yunlin;Liu, Zhi;Chun, Su-Kyoung
    • Journal of the Korea Furniture Society
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    • v.17 no.2
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    • pp.1-7
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    • 2006
  • A chinese wood species called China Hongmu, is an excellent wood to make high quality furniture owing to attracting color, beautiful grain, and durability. Hongmu is not a tree or wood species name. The general designation in Hongmu group is a similar to one of its density, structure, color and use. Hongmu considers more than 30 hardwood species of Pterocarpus, Dalbergia, Diospyros, Millettia, and Cassia. According to the macrostructural characteristics and properties, Hongmu group can be classified into 8 groups which are Zitanmulei, Hualimulei, Heisuanzhimulei, Hongsuanzhimulei, Xiangzhimulei, Wumulei, Tiaowenwumulei and Jichimulei. In this paper, the growing areas, scientific names and identifiable characteristics of these Hongmu group species were introduced for help to identify China Hongmu and its products in the market as well.

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The Research Regarding of Visitors' Perception of Animal Elements in Landscape Architecture

  • Shen, Ning;Bae, Jung Nam;Zhang, Li-Qin;Piao, Yong-Ji
    • Journal of Environmental Science International
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    • v.22 no.6
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    • pp.679-686
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    • 2013
  • Based on the survey of East Lake Park, South Lake Park and Tian Waicun in Tai'an by questionnaire survey, on-the-spot investigation and in-depth interview, the paper analyzes the tendencies of visitors to the animal elements and animal landscape in landscape architecture from three terms: primary attributes, the cognition of animal elements and animal elements landscape preferences. We have drawn several conclusions: the landscapes of animal elements are in urgent demand by the public ; The animal elements having lovely image, auspicious meaning and local characteristics are the most popular application types of animal elements landscapes ; The most favorite types of animals and animal elements are: doves, cranes monkeys, pandas, butterflies, dragonflies, fold fish, dolphins, dragons and cartoon animals ; The popular landscaping techniques of animal elements are the methods of combining with plants, buildings and garden ornaments.

Effects of Length and Grade on In-grade Tensile Strength and Stiffness Properties of Radiata Pine Timber

  • Tsehaye, Addis;Buchanan, A.H.;Cha, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.2
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    • pp.16-23
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    • 1998
  • This paper examines the effects of specimen length and grade on the strength and stiffness properties of structural timber of radiata pine. The tensile strength and modulus of elasticity of 1,902 machine-graded boards with 3.15- and 1.62-m clear span lengths, were determined using a horizontal tension test machine. The mean failure and characteristic stress values for tensile strength show an extremely high dependency on test specimen length. The mean and characteristic values of both modulus of elasticity and tensile strength show significant dependency on machine stress grades.

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