• Title/Summary/Keyword: Sampling Density

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SOIL ORGANIC CARBON APPRAISAL IN A SEMI-EVERGREEN FOREST, EASTERN GHATS OF INDIA AS A RESULT OF DEGRADATION - A GEOSPATIAL STUDY

  • Jayakumar, S.;Ramachandran, A.;Bhaskaran, G.;Cho, Hyoung-Sig;Heo, Joon
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.98-100
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    • 2007
  • Tropical forests have variety of biodiversity values, which provide invaluable services to the living being on earth. In the recent years, tropical forests are regarded as valuable global resources that act as sink for carbon dioxide in order to mitigate global climatic change. In many parts of the world, tropical forests are being rapidly cleared by various means. Soil organic carbon (SOC) is concentrated in the upper 12 inches of the soil. So it is readily depleted owing to the degradation activities. In the present study, it was aimed to assess the magnitude of disturbance in the availability of SOC in a semi- evergreen forest, situated in the Eastern Ghats of Tamil Nadu, India. The forest density of this region was mapped with QuickBird satellite data. Intensive field soil sampling and floristic study were conducted to estimate the SOC status in different density classes and to identify the species availability. The SOC density ranged from 274.06 t/ha to 147.84 t/ha in the very dense and degraded semi-evergreen forest respectively. The SOC content was also varied from 3.70 to 1.83 % in the very dense semi-evergreen and medium semi-evergreen forests respectively. The species composition in different density classes was also varied considerably. As a result of this study, it was identified that the disturbance to forests by various means not only affect the density of forests but also affect the below ground SOC status proportionately.

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Study on the Sampling of Distributors : Relating Olfactory Cues and Social Density (유통점의 샘플링에 관한 연구 : 후각적 자극과 매장 밀집도를 중심으로)

  • Hwang, Hee-Joong;Youn, Myoung-Kil
    • Journal of Distribution Science
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    • v.16 no.9
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    • pp.59-63
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    • 2018
  • Purpose - It has already been proved that 'mood' as the physical environment of shopping affects consumers' main sensory channels such as sight, hearing, smell, touch. However, there is no consensus on how the olfactory cue influences the customers in the shopping environment. In this study, we examine the previous studies on how the olfactory cue affects the customers in the shopping environment and present a clear direction as a suggestion for progressive research. Research design, data, and methodology - It is not important to use a lot of unconditional fragrance, but it should be exposed to the environment that suits the proper fragrance. In recent years, meaningful research on store fragrance has been slowly increasing. As a result, studies on the fragrance effects of retail stores have been conducted to verify the relevance of fragrance suitability in stores and consumer spending scale. Results - The fragrance appropriate for each store can not be uniformly specified as any fragrance. This is because external variables such as time, season, temperature, lighting, density of shoppers, and music in the store also affect customer evaluation. For example, using an unsuitable fragrance may encourage customers to leave the store quickly by restraining impulsive purchases or by disturbing concentration. The store manager should also be interested in using fragrances that are proven and effective in the store environment, but they should also have the ability to easily manipulate and manage the fragrances very appropriately according to changes in the store environment. Store managers should observe consumer preferences and responses according to their goals and strategies, and then systematically manage and store information about the fragrance appropriate to the store. Conclusions - In the future, the fragrance marketing researcher needs to consider the spatial form and density of the customer. In practice, managers operating a retail store should check the most appropriate store density(congestion) according to the size and spatial characteristics of the store and maintain the ideal conditions. To do this, it is necessary to pay attention to how to select and control sensory elements such as fragrance(olfactory), music(auditory), and lighting(visual).

Seasonal Variation of Caprellids (Crustacea: Amphipoda) on Blades of Zostera marina in Kwangyang Bay, Korea (광양만 잘피엽상에 서식하는 바다대벌레류의 계절변동)

  • Yun Sung Gyu;Byun Sung Hye;Kwak Seok Nam;Huh Sung Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.2
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    • pp.105-109
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    • 2002
  • Seasonal variations of species composition and density of caprellids was accomplished in eelgrass beds around Daedo Island, a south coast of Korea. Sampling was performed monthly using an epifaunal sampler at two stations from June 1996 to May 1997, Caprellids were comprised of 6 species belong to a family Caprellidae, Mean density was 402 ind./$m^2$. The numerically-dominant species were Caprella tsugarensis (216 ind./$m^2$) and C. kroeyeri (129 ind./$m^2$). High density was occurred in the early summer, and lows in autumn and winter. The density of caprellids was correlated with the biomass of the eelgrass. Predation pressure by fish was also correlated with the density of caprellids in spring.

Effects of Mowing and TIBA(Triiodobenzoic acid) on Dry Matter Production of Cultivated Zoysia japonica Community (잔디깍기와 TIBA 처리가 잔디 인공군락의 물질생산에 미치는 영향)

  • 진희성
    • Journal of Plant Biology
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    • v.30 no.2
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    • pp.135-149
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    • 1987
  • An experiment was made in order to analyze the growth characteristics and productivity of Zoysia japonica under control, mowing and TIBA treatment conditions at the experimental farm of Kyung Hee University. The field was planned by the split plot design method and each treatment was given to two plots (40$\times$40 and 100$\times$100 mm) and was replicated three times. Each plot was 9$m^2$ for Zoysia japonica. The sampling of each plot was taken once a week after sowing. In order to know the dry matter of total standing crops, each organ of plants was kept at 9$0^{\circ}C$ and weighed. Total leaf area of a plant was measured by drawing method. The author adopted the growth analysis of English School. Holocellulose analysis by sodium chlorite method was made. The increasing rate of LAI was high in all plots between 10th and 12th week after sowing and high growth rate of assimilatory organ was observed in low density area of TIBA plot. Between 10th and 12th week after sowing all the experimental plots showed high increasing rate of standing crop and in the process of growth each density area of TIBA plot recorded high increasing rate. In all the plots F/C ratio and RGR were high when the growth rate of assimilatory organ was increasing cosiderably, and the higher the planting density was, the higher F/C ratio was recorded. In all the plots NAR recorded maximum rate before the growth period to show a high increase of RGR. In the process of the growth TIBA plot showed high icnreasing rate of NAR. CGR showed high value in high density areas of all the plots and reached its maximum in the 13th week after sowing. Compared to the other experimental areas the low planting density areas of control plot and TIBA plot showed considerable earlier lignification indicating low Holocellulose content in the growth process.

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A Digital Readout IC with Digital Offset Canceller for Capacitive Sensors

  • Lim, Dong-Hyuk;Lee, Sang-Yoon;Choi, Woo-Seok;Park, Jun-Eun;Jeong, Deog-Kyoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.3
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    • pp.278-285
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    • 2012
  • A digital readout IC for capacitive sensors is presented. Digital capacitance readout circuits suffer from static capacitance of sensors, especially single-ended sensors, and require large passive elements to cancel such DC offset signal. For this reason, to maximize a dynamic range with a small die area, the proposed circuit features digital filters having a coarse and fine compensation steps. Moreover, by employing switched-capacitor circuit for the front-end, correlated double sampling (CDS) technique can be adopted to minimize low-frequency device noise. The proposed circuit targeted 8-kHz signal bandwidth and oversampling ratio (OSR) of 64, thus a $3^{rd}$-order ${\Delta}{\Sigma}$ modulator operating at 1 MH was used for pulse-density-modulated (PDM) output. The proposed IC was designed in a 0.18-${\mu}m$ CMOS mixed-mode process, and occupied $0.86{\times}1.33mm^2$. The measurement results shows suppressed DC power under about -30 dBFS with minimized device flicker noise.

SHM-based probabilistic representation of wind properties: Bayesian inference and model optimization

  • Ye, X.W.;Yuan, L.;Xi, P.S.;Liu, H.
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.601-609
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    • 2018
  • The estimated probabilistic model of wind data based on the conventional approach may have high discrepancy compared with the true distribution because of the uncertainty caused by the instrument error and limited monitoring data. A sequential quadratic programming (SQP) algorithm-based finite mixture modeling method has been developed in the companion paper and is conducted to formulate the joint probability density function (PDF) of wind speed and direction using the wind monitoring data of the investigated bridge. The established bivariate model of wind speed and direction only represents the features of available wind monitoring data. To characterize the stochastic properties of the wind parameters with the subsequent wind monitoring data, in this study, Bayesian inference approach considering the uncertainty is proposed to update the wind parameters in the bivariate probabilistic model. The slice sampling algorithm of Markov chain Monte Carlo (MCMC) method is applied to establish the multi-dimensional and complex posterior distribution which is analytically intractable. The numerical simulation examples for univariate and bivariate models are carried out to verify the effectiveness of the proposed method. In addition, the proposed Bayesian inference approach is used to update and optimize the parameters in the bivariate model using the wind monitoring data from the investigated bridge. The results indicate that the proposed Bayesian inference approach is feasible and can be employed to predict the bivariate distribution of wind speed and direction with limited monitoring data.

Characteristics of Benthic Chlorophyll a and Sediment Properties in the Tidal Flats of Kwangyang Bay, Korea

  • Sin, Yong-Sik;Ryu, Sang-Ock;Song, Eun-Sook
    • ALGAE
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    • v.24 no.3
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    • pp.149-161
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    • 2009
  • Characteristics of benthic microalgae and sediment properties were investigated for the intertidal flats of Kwangyang Bay, Korea. Sampling stations were selected every 100 m in the intertidal flats from land-side to open ocean at two different sampling sites. Samples were collected in June 2004, July, September, November, February and May 2005. Sediments properties were measured including temperature, water contents, sediment bulk density, nutrient concentrations in porewater. Chlorophyll a concentrations in surface sediment (0.5 cm) were measured and relationships between the chlorophyll a and various sediment properties were analyzed to identify major mechanisms regulating biomass of benthic microalgae in the intertidal flats using simple linear regression analysis. Sediment chlorophyll a concentrations were maximum during winter and minimum during warm seasons ranging from 4.4 mg $m^{-2}\;to\;81.2\;mg\;m^{-2}$. No clear spatial variations were observed for the sediment chlorophyll a in the study sites. Results from regression analysis suggested that benthic microalgae biomass was affected by sediment temperature and nutrients especially ammonium and silicate. Grazing effect was estimated using chlorophyll: pheopigments ratio, indirect indicator of grazing activity, and the positive correlation of the ratio and chlorophyll a implied that microalgae biomass is affected by grazing of zoobenthos although direct measurement of grazing activity is required to determine the importance of top-down controls in the benthic microalgae dynamics.

Design wind speed prediction suitable for different parent sample distributions

  • Zhao, Lin;Hu, Xiaonong;Ge, Yaojun
    • Wind and Structures
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    • v.33 no.6
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    • pp.423-435
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    • 2021
  • Although existing algorithms can predict wind speed using historical observation data, for engineering feasibility, most use moment methods and probability density functions to estimate fitted parameters. However, extreme wind speed prediction accuracy for long-term return periods is not always dependent on how the optimized frequency distribution curves are obtained; long-term return periods emphasize general distribution effects rather than marginal distributions, which are closely related to potential extreme values. Moreover, there are different wind speed parent sample types; how to theoretically select the proper extreme value distribution is uncertain. The influence of different sampling time intervals has not been evaluated in the fitting process. To overcome these shortcomings, updated steps are introduced, involving parameter sensitivity analysis for different sampling time intervals. The extreme value prediction accuracy of unknown parent samples is also discussed. Probability analysis of mean wind is combined with estimation of the probability plot correlation coefficient and the maximum likelihood method; an iterative estimation algorithm is proposed. With the updated steps and comparison using a Monte Carlo simulation, a fitting policy suitable for different parent distributions is proposed; its feasibility is demonstrated in extreme wind speed evaluations at Longhua and Chuansha meteorological stations in Shanghai, China.

A novel Metropolis-within-Gibbs sampler for Bayesian model updating using modal data based on dynamic reduction

  • Ayan Das;Raj Purohit Kiran;Sahil Bansal
    • Structural Engineering and Mechanics
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    • v.87 no.1
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    • pp.1-18
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    • 2023
  • The paper presents a Bayesian Finite element (FE) model updating methodology by utilizing modal data. The dynamic condensation technique is adopted in this work to reduce the full system model to a smaller model version such that the degrees of freedom (DOFs) in the reduced model correspond to the observed DOFs, which facilitates the model updating procedure without any mode-matching. The present work considers both the MPV and the covariance matrix of the modal parameters as the modal data. Besides, the modal data identified from multiple setups is considered for the model updating procedure, keeping in view of the realistic scenario of inability of limited number of sensors to measure the response of all the interested DOFs of a large structure. A relationship is established between the modal data and structural parameters based on the eigensystem equation through the introduction of additional uncertain parameters in the form of modal frequencies and partial mode shapes. A novel sampling strategy known as the Metropolis-within-Gibbs (MWG) sampler is proposed to sample from the posterior Probability Density Function (PDF). The effectiveness of the proposed approach is demonstrated by considering both simulated and experimental examples.

Cultivation Method of Cordyceps militaris Mycelium Using Tenebrio molitor Larvae to Produce High Content Cordycepin

  • Neul-I Ha;Seul-Ki Mun;Seung-Bin Im;Hee-Gyeong Jeong;Kyoung-Sun Seo;Seung-Eon Ban;Kyung-Je Kim;Sung-Tae Yee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2022.09a
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    • pp.115-115
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    • 2022
  • The Food and Agriculture Organization (FAO) has been estimating the potential of insects as human food and animal feed for convincing food security since 2010. On account of this reason, Tenebrio molitor larvae have been gaining considerable attention as an alternative protein source for various foods. However, consumers do not prefer them because of their disgusting appearance. Therefore, it is necessary to develop a method that improve their appearance as to lead to T. molitor larvae consumption. In this study, T. molitor larvae which is prepared for optimally sampling conditions (shade drying, 30 min boiling after hot air drying, 30 min steaming after hot air drying), were cultured with Cordyceps militaris mycelia, and measured growth and density of mycelial. Also analyzed the cordycepin and adenosine content compared with commercial C. militaris. As a result, T. molitor larvae cultivated with C. militaris mycelia showed the highest cordycepin content (13.75 mg/g) was observed in optimal sampling conditions (shade drying). Therefore, we report that the methods which T. molitor larvae cultivated with C. militaris mycelia not only improve their appearance but also increase cordycepin content, which can be contributed to lead T. molitor larvae consumption.

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