• Analytical Science and Technology
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• v.20 no.2
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• pp.138-146
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• 2007

A simple and sensitive method for the determination of paroxetine in canine plasma was developed and validated by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry (LC-/MS/MS). Fluoxetine was used as an internal standard. Paroxetine and internal standard in plasma samples were extracted using TBME (tert-butyl methyl ether). A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 50% acetonitrile adjusted to pH 3 by formic acid. The reconstituted samples were injected into a Capcell Pak UG120 ($2.0{\times}150mm$, $5{\mu}m$) column. Using MS/MS with SRM (selective reaction monitoring) mode, the transitions (precursor to product) monitored were m/z $330{\rightarrow}192$ for paroxetine, and m/z $310{\rightarrow}148$ for internal standard. Linear detection responses were obtained for paroxetine concentration range of 0.02~5 ng/mL. A correlation coefficient of linear regression ($R^2$) was 0.9993. Detection of paroxetine in canine plasma was accurate and precise, with limit of quantification at 0.02 ng/mL. The method has been successfully applied to pharmacokinetic study of paroxetine in healthy beagle dogs.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.117-124
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• 2023

The management of Ricania spp. is difficult because this pest has a wide host range and diverse habitats such as agricultural, suburban, urban, and forested areas. However, the researches for Ricania spp. management have been focused on only agricultural crops. Thus, it is required to determine the arboreal host preference of Ricania spp. at the surrounding areas of the farms to increase its management efficiency. To determine its host preference at arboreal plants, we reviewed the previous studies and investigated the densities of Ricania spp. at woody plants with high ecological importance but insufficiently studied. This study identified 120 species in 53 families of arboreal hosts of Ricania spp. Only Cornus officinalis and Styrax japonicus were preferred by all developmental stages of Ricania spp. The host preference of Ricania spp. was changed according to its developmental stages. This phenomenon would be caused by that each developmental stage of Ricania spp. would prefer different parts of woody plant, and require different nutrients for its survivor and reproduction. These results of this study could be helpful to make a plan of comprehensive management strategies for Ricania spp.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.765-774
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• 2023

Due to climatechange, precipitation variability has increased, leading to more frequentoccurrences of droughts and floods. To establish measures for managing waterresources in response to the increasing uncertainties of climate conditions, itis necessary to understand the variability of natural river discharge and theimpact of reservoir operation modeling considering dam inflow and artificialwater supply. In this study, an integrated rainfall-runoff and reservoiroperation modeling was applied to analyze the water supply reliability andflood risk for a multipurpose dam catchment under climate change conditions. Therainfall-runoff model employed was the modèle du Génie Rural à 4 paramètresJournalier (GR4J) model, and the reservoir operation model used was an R-basedmodel with the structure of HEC-Ressim. Applying the climate change scenariosuntil 2100 to the established integrated model, the changes in water supplyreliability and flood risk of the Happcheon Dam were quantitatively analyzed.The results of the water supply reliability analysis showed that under SSP2-4.5conditions, the water supply reliability was higher than that under SSP5-8.5conditions. Particularly, in the far-future period, the range of flood risk widened,and both SSP2-4.5 and SSP5-8.5 scenarios showed the highest median flood riskvalues. While precipitation and runoff were expected to increase by less than10%, dam-released flood discharge was projected to surge by over 120% comparedto the baseline

• Korean Journal of Optics and Photonics
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• v.35 no.3
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• pp.107-114
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• 2024

In this study, the feasibility of using the covariance-matrix-adaptation-evolution-strategy (CMA-ES) algorithm in a multichannel coherent-beam-combining (CBC) system was experimentally verified. We constructed a multichannel CBC system utilizing a spatial light modulator (SLM) as a multichannel phase-modulator array, along with a coherent light source at 635 nm, implemented the stochastic-parallel-gradient-descent (SPGD) and CMA-ES algorithms on it, and compared their performances. In particular, we evaluated the characteristics of the CMA-ES and SPGD algorithms in the CBC system in both 16-channel rectangular and 19-channel honeycomb formats. The results of the evaluation showed that the performances of the two algorithms were similar on average, under the given conditions; However, it was verified that under the given conditions the CMA-ES algorithm was able to operate with more stable performance than the SPGD algorithm, as the former had less operational variation with the initial phase setting than the latter. It is emphasized that this study is the first proof-of-principle demonstration of the CMA-ES phase-control algorithm in a multichannel CBC system, to the best of our knowledge, and is expected to be useful for future experimental studies of the effects of additional channel-number increments, or external-phase-noise effects, in multichannel CBC systems based on the CMA-ES phase-control algorithm.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.373-386
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• 2024

The aim of this study is to establish a system for the early detection of high-density harmful marine organisms. Considering its accuracy and processing speed, YOLOv8m (You Only Look Once version 8 medium) is selected as a suitable model for real-time underwater image-based object detection. Applying the detection algorithm allows one to detect numerous fish and the occasional occurrence of jellyfish. The average precision, recall rate, and mAP (mean Average Precision) of the trained model are 0.931, 0.881, and 0.948 for the validation data, respectively. Also, the mAP for each class is 0.97 for fish, 0.97 for jellyfish and 0.91 for salpa, all of which exceed 0.9 (90%) for classes demonstrating the excellent performance of the model. A scientific sonar system is used to address the object-detection range and validate the detection results. Additionally, integrating and grid averaging the echo strength allows the detection results to be smoothed in space and time. Mean-volume back-scattering strength values are obtained to reflect the detection variability within the analysis domain. Furthermore, an underwater image-based object (marine lives) detection algorithm, an image-correction technique based on the underwater environmental conditions (including nights), and quantified detection results based on a scientific sonar system are presented, which demonstrate the utility of the detection system in various applications.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.1-25
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• 1982

Limnological study on the physico-chemical properties and biological characteristics of the Lake Ok-Jeong was made from May 1980 to August 1981. For the planktonic organisms in the lake, species composition, seasonal change and diurnal vertical distribution based on the monthly plankton samples were investigated in conjunction with the physico-chemical properties of the body of water in the lake. Analysis of temperature revealed that there were three distinctive periods in terms of vertical mixing of the water column. During the winter season (November-March) the vertical column was completely mixed, and no temperature gradient was observed. In February temperature of the whole column from the surface to the bottom was $3.5^{\circ}C$, which was the minimum value. With seasonal warming in spring, surface water forms thermoclines at the depth of 0-10 m from April to June. In summer (July-October) the surface mixing layer was deepened to form a strong thermocline at the depth of 15-25 m. At this time surface water reached up to $28.2^{\circ}C$ in August, accompanied by a significant increase in the temperature of bottom layer. Maximum bottom temperature was $r5^{\circ}C$ which occurred in September, thus showing that this lake keeps a significant turbulence Aehgh the hypolimnial layer. As autumn cooling proceeded summer stratification was destroyed from the end of October resulting in vertical mixing. In surface layer seasonal changes of pH were within the range from 6.8 in January to 9.0 in guutuost. Thighest value observed in August was mainly due to the photosynthetic activity of the phytoplankton. In the surface layer DO was always saturated throughout the year. Particularly in winter (January-April) the surface water was oversaturated (Max. 15.2 ppm in March). Vertical variation of DO was not remarkable, and bottom water was fairly well oxygenated. Transparency was closely related to the phytoplankton bloom. The highest value (4.6 m) was recorded in February when the primary production was low. During summer transparency decreased hand the lowest value (0.9 m) was recorded in August. It is mainly due to the dense blooming of gnabaena spiroides var. crassa in the surface layer. A. The amount of inorganic matters (Ca, Mg, Fe) reveals that Lake Ok-Jeong is classified as a soft-water lake. The amount of Cl, $NO_3-N$ and COD in 1981 was slightly higher than those in 1980. Heavy metals (Zn, Cu, Pb, Cd and Hg) were not detectable throughout the study period. During the study period 107 species of planktonic organisms representing 72 genera were identified. They include 12 species of Cyanophyta, 19 species of Bacillariophyta, 23 species of Chlorophyta, 14 species of Protozoa, 29 species of Rotifera, 4 species of Cladocera and 6 species of Copepoda. Bimodal blooming of phytoplankton was observed. A large blooming ($1,504\times10^3\;cells/l$ in October) was observed from July to October; a small blooming was present ($236\times10^3\;cells/l$ in February) from January to April. The dominant phytoplankton species include Melosira granulata, Anabaena spiroides, Asterionella gracillima and Microcystis aeruginota, which were classified into three seasonal groups : summer group, winter group and the whole year group. The sumner group includes Melosira granulate and Anabaena spiroides ; the winter group includes Asterionella gracillima and Synedra acus, S. ulna: the whole year group includes Microtystis aeruginosa and Ankistrodesmus falcatus. It is noted that M. granulate tends to aggregate in the bottom layer from January to August. The dominant zooplankters were Thermocpclops taihokuensis, Difflugia corona, Bosmina longirostris, Bosminopsis deitersi, Keratelle quadrata and Asplanchna priodonta. A single peak of zooplankton growth was observed and maximum zooplankton occurrence was present in July. Diurnal vertical migration was revealed by Microcystis aeruginosa, M. incerta, Anabaena spiroides, Melosira granulata, and Bosmina longirostris. Of these, M. granulata descends to the bottom and forms aggregation after sunset. B. longirostris shows fairly typical nocturnal migration. They ascends to the surface after sunset and disperse in the whole water column during night. Foully one species of fish representing 31 genera were collected. Of these 13 species including Pseudoperilnmpus uyekii and Coreoleuciscus splendidus were indigenous species of Korean inland waters. The indicator species of water quality determination include Microcystis aeruginosa, Melosira granulata, Asterionelta gracillima, Brachionus calyciflorus, Filinia longiseta, Conochiloides natans, Asplanchna priodonta, Difflugia corona, Eudorina elegans, Ceratium hirundinella, Bosmina longirostris, Bosminopsis deitersi, Heliodiaptomus kikuchii and Thermocyclops taihokuensis. These species have been known the indicator groups which are commonly found in the eutrophic lakes. Based on these planktonic indicators Lake Ok-Jeong can be classified into an eutrophic lake.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.34-40
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• 2021

Purpose If a new test is introduced or reagents are changed in the laboratory of a medical institution, the characteristics of the test should be analyzed according to the procedure and the assessment of reagents should be made. However, several necessary conditions must be met to perform all required comparative evaluations, first enough samples should be prepared for each test, and secondly, various reagents applicable to the comparative evaluations must be supplied. Even if enough comparative evaluations have been done, there is a limit to the fact that the data variation for the new reagent represents the overall patient data variation, The fact puts a burden on the laboratory to the change the reagent. Due to these various difficulties, reagent changes in the laboratory are limited. In order to introduce a competitive bid, the institute conducted a full investigation of Radioimmunoassay(RIA) reagents for each test and established the range of reagents available in the laboratory through comparative evaluations. We wanted to share this process. Materials and Methods There are 20 items of tests conducted in our laboratory except for consignment tests. For each test, RIA reagents that can be used were fully investigated with the reference to external quality control report. and the manuals for each reagent were obtained. Each reagent was checked for the manual to check the test method, Incubation time, sample volume needed for the test. After that, the primary selection was made according to whether it was available in this laboratory. The primary selected reagents were supplied with 2kits based on 100tests, and the data correlation test, sensitivity measurement, recovery rate measurement, and dilution test were conducted. The secondary selection was performed according to the results of the comparative evaluation. The reagents that passed the primary and secondary selections were submitted to the competitive bidding list. In the case of reagent is designated as a singular, we submitted a explanatory statement with the data obtained during the primary and secondary selection processes. Results Excluded from the primary selection was the case where TAT was expected to be delayed at the moment, and it was impossible to apply to our equipment due to the large volume of reagents used during the test. In the primary selection, there were five items which only one reagent was available.(squamous cell carcinoma Ag(SCC Ag), β-human chorionic gonadotropin(β-HCG), vitamin B12, folate, free testosterone), two reagents were available(CA19-9, CA125, CA72-4, ferritin, thyroglobulin antibody(TG Ab), microsomal antibody(Mic Ab), thyroid stimulating hormone-receptor-antibody(TSH-R-Ab), calcitonin), three reagents were available (triiodothyronine(T3), Tree T3, Free T4, TSH, intact parathyroid hormone(intact PTH)) and four reagents were available are carcinoembryonic antigen(CEA), TG. In the secondary selection, there were eight items which only one reagent was available.(ferritin, TG, CA19-9, SCC, β-HCG, vitaminB12, folate, free testosterone), two reagents were available(TG Ab, Mic Ab, TSH-R-Ab, CA125, CA72-4, intact PTH, calcitonin), three reagents were available(T3, Tree T3, Free T4, TSH, CEA). Reasons excluded from the secondary selection were the lack of reagent supply for comparative evaluations, the problems with data reproducibility, and the inability to accept data variations. The most problematic part of comparative evaluations was sample collection. It didn't matter if the number of samples requested was large and the capacity needed for the test was small. It was difficult to collect various concentration samples in the case of a small number of tests(100 cases per month or less), and it was difficult to conduct a recovery rate test in the case of a relatively large volume of samples required for a single test(more than 100 uL). In addition, the lack of dilution solution or standard zero material for sensitivity measurement or dilution tests was one of the problems. Conclusion Comparative evaluation for changing test reagents require appropriate preparation time to collect diverse and sufficient samples. In addition, setting the total sample volume and reagent volume range required for comparative evaluations, depending on the sample volume and reagent volume required for one test, will reduce the burden of sample collection and planning for each comparative evaluation.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.118-131
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• 1982

1. In order to investigate the effect of variation of assembly time on glue bond strength, and to determine the optimum range of assembly time with given glue, this experiment was made at the suggestion of the Wood Technology Laboratory, School of Forestry, Yale University. 2. For this investigation, three-ply-plywoods with 1/22 inch, birch veneer, phenolic resin, and soybean glue were made at the following variation of assembly time, that is, 1, 5, 10, 25, 35, 50, and 70 minutes, under both open and closed assembly manners, and the shear strength test at dry and wet were adoptted. 3. The shear strength and wood failure of each plywood panel constructed at the given assembly time have been illustrated in Tables 1, 2, 3 and 4. It has shown that there is a remarkable tendency, for increasing assembly time to give lower shear strength and wood failure throughout almost all cases. The effective range of assembly time of tested glues in this investigation for both open and closed assembly are summarized in the Table 7. Thus, allowable assembly time for Phenolic resin may be up to 10 minutes under open assembly and up to 50 minutes under closed assembly. For soybean glue, the permissible assembly time may be up to 5 minutes under open assembly and up to 15 minutes under closed assembly. The allowable assembly time for open assembly with the same glue is reduced by approximately one third or more than one third as compared with closed assembly time. This might mean that the closed asembly time for these glues is more practical than the open assembly.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.761-772
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• 1998

This study was performed to determine the optimum coagulant dosing amount for effective treatment of raw water. The removal rate of turbidity and the variations of water qualities according to various dosage of coagulants such as Alum, PAC and PACS were investigated. The optimum coagulant dosing amount to make the lowest turbidity of water were 35mg/ι t of Alum, 30mg/ι of PAC and 10mg/ι of PACS in case of 5 NTU of raw water turbidity, and 30mg/ι of Alum, 25mg/ι of PAC and 10mg/ι of PACS in case of 10 NTU of that, respectively. The removal rates of turbidity at 4 min. and 8 min. of settling time were 10 and 72% of Alum, 44 and 62% of PAC and 25 and 55% of PACS in case of 5 NTU, and 52 and 70% of Alum, 90 and 95% of PAC and 10 and 28% of PACS in case of 10 NTU, respectively. Judging from the settling capability of floc., the reaction time of floe. formation and removal efficiency of turbidity, PAC was evaluated as more effective coagulant than Alum and PACS. Also PAC was regarded as the most effective coagulant when the water supply was changed sharply and the fluctuation of the surface loading occured with wide and sharp in settling basin. pH and alkalinity of the water were decreased with increasing coagulants dosage. But pH and alkalinity were not decreased below 5.8 which is the standard for drinking water quality, and 10mg/ι which is the limit concentration of floc. breakage, respectively. Residual Al of the treated water was decreased with increasing coagulants dosage in case of 5 and 10NTU of raw water turbidity. $KMnO_4$ consumption of the water was decreased with increasing coagulants dosage. The reduction rate of $KMnO_4$ consumption at the optimum coagulants dosage were 39% of Alum. 18% of PAC and 11% of PACS in case of 5 NTU of raw water turbidity, and 42% of Alum, 27% of PAC and 36% of PACS in case of 10 NTU of that, respectively. Any relationship was not found between the removal rate of turbidity and KMnO$_4$ consumption. TOC of the water was a bit decreased with increasing coagulants dosage up to 30mg/ι but not changed above 30mg/ι of coagulants dosage. The degree of TOC reduction was increased in the order of Alum, PAC and PACS treatment. Zeta potential of the colloidal floe. at the optimum coagulants dosage was in the range of -20~-15mV in case of 5 NTU of raw water turbidity and 0~0.5mV in case of 10 NTU of that. respectively. Although the kinds and dosages of coagulants were different, zeta potential range were fixed under the conditions of the best coagulation efficiency.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.49-59
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• 2011

This study is a reinterpretation of characteristics of public space in contemporary cities with a view to liminal space. The conditions of pubic space now cannot be captured through the existing discourses of publicness, and public space. The basic premise of the study is that the idea of liminal space or liminality is useful to grasp the fluid and hybrid attribute of public space in contemporary cities. Liminal space, originally from anthropological studies, is the intermingled stage between two realms and the sustained period of the ritual. The idea has been widely used for various cultural phenomenon and spatial experiences. A literature review on public space and liminal space was carried out. Cases pertaining to public space with a view to liminal space were examined and discussed in detail. Through the careful reading of several public spaces with an angle toward liminal space, the new perspective toward public space will be drawn out. First, we need to emphasize the fluid spectrum of public space rather than the serial stage such as the public, the semi-public, the semi-private, and the private. Second, the idea will contribute to understanding the flexible state depending upon time. What we can learn from case studies is the volatile characteristics in public space as a common phenomenon support its vitality. This interpretation will contribute to the perception of a new horizon of public space. The nature of public space is unpredictable and free. In reality, the spectrum of public space will expand and fluctuate. Ironically, public space can be vitalized through enhancing and activating the private space. The intimate and complicated interface between the two realms is a key issue. The boundary of public space might be redefined to embrace the flexible the fragile nature of changing public space. These research implications will guide the thoughtful design and management of pubic space.