• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.3
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• pp.1-13
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• 2024

This paper proposes a cost-effective system design and user-friendly approach for the key technological elements necessary to configure an autonomous mobile robot. To implement a high-precision positioning system using an autonomous mobile robot, we established a Linux-based VRS (virtual reference station)-RTK (real-time kinematic) GNSS (global navigation satellite system) system with NTRIP (Network Transport of RTCM via Internet Protocol) client functionality. Notably, we reduced the construction cost of the GNSS positioning system by performing dynamic location analysis of the established system, without utilizing an RTK replay system. Dynamic location analysis involves sampling each point during the trajectory following of the autonomous mobile robot and comparing the location precision with ground-truth points. The proposed system ensures high positioning performance with fast sampling times and suggests a GPS waypoint system for user convenience. The centimeter-level precision GNSS information is provided at a 30Hz sampling rate, and the dead reckoning function ensures valid information even when passing through tall buildings and dense forests. The horizontal position error measured through the proposed system is 6.7cm, demonstrating a highly precise dynamic location measurement error within 10cm. The VRS network-RTK Linux system, which provides precise dynamic location information at a high sampling rate, supports a GPS waypoint planner function for user convenience, enabling easy destination setting based on GPS information.

• Journal of Korean social welfare administration
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• v.21 no.1
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• pp.105-130
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• 2019

This study focuses on the duration of regular donors who are one of the key resources for stable operation of nonprofit charity organizations. Regular donors can have a choice between selecting preferred target subjects on different target subjects and delegating authority to charity organizations for execution of the contribution. This study examine the comparative validity of the hypothesis of identification effect and the hypothesis of authority delegation effect. It fully uses the regular donors' data from one charitable organization called S charity organization. In analysis, it employes Weibull model among parametric survival analysis methods based on the fitness of distribution. The result showed that regular donors who delegate authority have significantly longer duration of donation than regular donors who designate and donate international target subjects. In other words, regular donors who select domestic target subjects as beneficiaries have significantly longer duration than regular donors who select international target subjects. This result suggests that in the two hypothetical explanations, domestic identification and authority delegation are equally valid. Finally, among control variables, age, committed amount each donation, status difference (regular donation vs. temporary donation) at the starting point, and the payment method were statistically significant predictors on the duration of regular donors. This study meaningfully deepen and broaden our understandings of regular donors' donation behavior and also provides strategic knowledge regarding managing and retaining regular donors for non-profit charity organizations.

• Analytical Science and Technology
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• v.31 no.4
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• pp.161-170
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• 2018

The epidemic of disorders associated with synthetic stimulants, such as methamphetamine (MA) and amphetamine (AP), is a health, social, legal, and financial problem. Owing to the high potential of their abuse and addiction, reliable analytical methods are required to detect and identify MA, AP, and their metabolites in biological samples. Thus, a dilute-and-shoot liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) was developed for simultaneous determination of MA, 4-hydroxymethamphetamine (4HMA), AP, and 4-hydroxyamphetamine (4HA) in urine. Urine sample ($100{\mu}L$) was mixed with $50{\mu}L$ of mobile phase consisting of 0.4 % formic acid and methanol and $50{\mu}L$ of working internal-standard solution. Aliquots of $8{\mu}L$ diluted urine was injected into the LC-MS/MS system. For all analytes, chromatographic separation was performed using a C18 reversed-phase column with gradient elution and a total run time of 5 min. The identification and quantification were performed by multiple reaction monitoring (MRM). Linear least-squares regression was conducted to generate a calibration curve, with $1/x^2$ as the weighting factor. The linear ranges were 2.0-200, 1.0-800, and 10-2500 ng/mL for 4HA and 4HMA, AP, and MA, respectively. The inter- and intraday precisions were within 6.6 %, whereas the inter- and intraday accuracies ranged from -14.9 to 11.3 %. The low limits of quantification were 2.0 ng/mL (4HA and 4HMA), 1.0 ng/mL (AP), and 10 ng/mL (MA). The proposed method exhibited satisfactory selectivity, dilution integrity, matrix effect, and stability, which are required for validation. Moreover, the purification efficiency of high-speed centrifugation was clearly higher than 6-15 % for QC samples (n=5), which was higher than that of the membrane-filtration method. The applicability of the proposed method was tested by forensic analysis of urine samples from drug abusers.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.43-51
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• 2020

For developing a canopy photosynthesis model, an efficient method to measure the photosynthetic rate in a growth chamber is required. The objective of this study was to develop a method for establishing canopy photosynthetic rate curves of romaine lettuce (Lactuca sativa L.) with light intensity and CO₂ concentration variables using controlled growth chamber. The plants were grown in plant factory modules, and the canopy photosynthesis rates were measured in sealed growth chambers made of acrylic (1.0 × 0.8 × 0.5 m). First, the canopy photosynthetic rates of the plants were measured, and then the time constants were compared between two application methods: 1) changing light intensity (340, 270, 200, and 130 μmol·m^-2·s^-1) at a fixed CO₂ concentration (1,000 μmol·mol^-1) and 2) changing CO₂ concentration (600, 1,000, 1,400, and 1,800 μmol·mol^-1) at a fixed light intensity (200 μmol·m^-2·s^-1). Second, the canopy photosynthetic rates were measured by changing the light intensity at a CO₂ concentration of 1,000 μmol·mol^-1 and compared with those measured by changing the CO₂ concentration at a light intensity of 200 μmol·m^-2·s^-1. The time constant when changing the CO₂ concentration at the fixed light intensity was 3.2 times longer, and the deviation in photosynthetic rate was larger than when changing the light intensity. The canopy photosynthetic rate was obtained stably with a time lag of one min when changing the light intensity, while a time lag of six min or longer was required when changing the CO₂ concentration. Therefore, changing the light intensity at a fixed CO₂ concentration is more appropriate for short-term measurement of canopy photosynthesis using a growth chamber.

• Journal of Korea Port Economic Association
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• v.22 no.4
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• pp.1-17
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• 2006

In the Bill of Lading of The Irbenskiy Proliv is not subject to the Hague-Visby Rules in accordance with paragraphs (A) and/or (E) of cl.1 or to the Hague Rules in accordance with paragraphs (B) and/or (D) of cl.1. The Irbenskiy Proliv is very rare case that is effective to exempt the carrier as literal words of Bill of Lading. The action concerns cargoes of perishable goods shipped from Brazil to Japan, under Bills of Lading each of which contained an extensive carrier's exemption clause. A preliminary issue was ordered to be determined on the question whether c1.4 is effective to exempt the ralliers from any potential liability for the claims in this case. The court held that there is no reason to reject c1.4 as part of each of the contracts contained in or evidenced by the bills of lading; and it protects the carrier where damage to the goods shipped results from such causes. It is therefore effective to exempt the carriers from any potential liability for those claims.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.145-153
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• 1999

Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.102-108
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• 2006

It is very important to improve fertilizer use efficiency for the saving of fertilizers and for environmental purposes as well. However, there was no effective ways for the fertilization in the mid of growth under the plastic film mulching cultivation so far. For this, a Band Spotty Fertilization (BSF) machine was developed recently. So, we tried to establish a low input fertilization technique using this BSF machine in the vinyl mulching cultivation of onion (Allium cepa L.). Fertilization efficiency, soil properties, and crop yield were examined and compared among treatments from 2000 to 2001. The content of exchangeable K in soils were higher after fertilization but that of available $P_2O_5$ was lower than before the experiment in all plots. The content of nitrate-N was highest at the early growth stage, and higher in BSF plots than that of conventional fertilization (CF). BSF plot showed higher growth rate, and uptake amount of nitrogen of onion by 59-69% than that of CF. N use efficiency in BSF was higher in the order of two time-split application, one time-split application, and three time application. K use efficiency was high 13-17% BSF plots than that in CF($63kg\;ha^{-1}$) plots. The amount of residual N in soils was high by 8-14% in BSF plots compared to that in CF plots, and the loss of N was lowered 26-34% by BSF. Also, the amount of residual K in soils was high by 13-18% and the loss of K was low by 29-31% in BSF plots compared to that in CF plots. The yield of onions increased by 7-13% by BSF due to increased diameter and weight of bulbs. As the results, N fertilization efficiency increased by 22-42% by BSF.

• Journal of Animal Science and Technology
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• v.53 no.1
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• pp.1-6
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• 2011

This simulation study was performed to investigate the accuracy of the estimated breeding value by using genomic information (GEBV) by way of Bayesian framework. Genomic information by way of single nucleotide polymorphism (SNP) from a chromosome with length of 100cM were simulated with different marker distance (0.1cM, 0.5cM), heritabilities (0.1, 0.5) and half sibs families (20 heads, 4 heads). For generating the simulated population in which animals were inferred to genomic polymorphism, we assumed that the number of quantitative trait loci (QTL) were equal with the number of no effect markers. The positions of markers and QTLs were located with even and scatter distances, respectively. The accuracies of estimated breeding values by way of indicating correlations between true and estimated breeding values were compared on several cases of marker distances, heritabilities and family sizes. The accuracies of breeding values on animals only having genomic information were 0.87 and 0.81 in marker distances of 0.1cM and 0.5cM, respectively. These accuracies were shown to be influenced by heritabilities (0.87 at $h^2$ =0.10, 0.94 at $h^2$ =0.50). According to half sibs' family size, these accuracies were 0.87 and 0.84 in family size of 20 and 4, respectively. As half sibs family size is high, accuracy of breeding appeared high. Based on the results of this study it is concluded that the amount of marker information, heritability and family size would influence the accuracy of the estimated breeding values in genomic selection methodology for animal breeding.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.267-274
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• 2006

The evaluation of GB stones with ultrasound has proved to be useful procedure in patient with symptoms of cholelithiasis. GB is evaluated for size, wall thickness, presence of internal reflections within the lumen and posterior acoustic shadowing or enhancement in Ultrsonography. The patient position should be shifted during procedure to demonstrate further the presence of stone within the GB. Patient scanned at the Rt. subcostal region in supine, right lateral, Lt. down decubitus, and upright sitting position. So GB stone should shift to dependent area of GB. Often, GB is not markedly distended in the presence of cholethiasis, and so the diagnosis becomes more difficult. One of the more difficult areas for detection of a GB stones are embeded in the cystic duct region. And since the GB is adjacent to the duodenum and hepatic flexure, its may be difficult to visualizing a GB stone. When patient study position changes frome supine to other position, stones displaced the site. But if its are polyps, not changes the site whatever patient positions. It is very important to what make different GB stones or polyps. We have studied about mobility of GB stones according to the patients position(supine, Lt. down decubitus, $30^{\circ} LAO. sitting and hand-knee). So we have a result, stones wherever localized within the GB, changed 100% its position in the hand-knee position and the others appeared at least 90%. In this study, when a large stones are located through fundus-body and body-neck, does not changing the stones position in spite of varied patient's positions. But hand-knee positions can identified GB stones, because its make changed the position of stons from posterior wall to anterior wall within the GB. We recommend the hand-knee position for differentiation GB stones from polyps.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.253-260
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• 2005

Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P $(1,431{\sim}6,516mg\;kg^{-1}),\;NO_3-N\;(117.60{\sim}395.73mg\;kg^{-1})$, exchangeable Ca $(4.06{\sim}11.07\;cmol_c\;kg^{-1})$ and Mg $(2.59{\sim}18.76\;cmol_c\;kg^{-1})$, as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of $Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+,\;{NH_4}^+,\;{PO_4}^{3-}\;and\;{NO_3}^-$. Rice bran effectively removed ${PO_4}^{3-}\;and\;{NO_3}^-$ in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for $Ca^{2+}$ were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing $Mg^{2+},\;K^+,\;Na^+,\;and\;{NH_4}^+$. Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.