• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.587-592
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• 2016

Bellows for LNG carriers must be corrosion resistant in order to operate in seawater environments. They must also have long fatigue lives in order to withstand the expansion and contraction caused by large temperature changes and continuous vibration in extreme environments. In order to incorporate these properties into bellow design, it is important to use materials that are resistant to cold brittleness and corrosion, and maintain their optimized forming condition. The design conditions and forming methods used for bellows must be optimized in order to incorporate these characteristics. In this study, finite element analysis was used to develop cryogenic bellows, which have good mechanical strength and reliability. In addition, two different forming methods (mechanical and hydroforming) were used to design and produce bellows, in order to derive their forming condition. The height, thickness, and hardness of the convolutions of bellows produced by each method were measured and compared with each other. The results confirmed that the two forming methods produced bellows with different mechanical properties.

• Clean Technology
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• v.18 no.3
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• pp.287-294
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• 2012

In this study, performances of two cleaning methods were analyzed and a cleaning system was designed to develop a cleaning process of electronic components to remanufacture old laser copy machine. First, plasma cleaning as a dry cleaning method was executed to test cleaning ability. In cleaning of printed circuit board (PCB) by plasma, some damages were found near the metal parts, and considering the productivity, this method was not adequate for the cleaning of electronic components. With 4 different cleaning agents, ultrasonic cleaning tests were executed to select an optimal cleaning agent, aqueous agents showed superior cleaning performance compared to semi-aqueous and non-aqueous agents. Cleaning with aqueous cleaning agent A and 28 kHz ultrasonic frequency can be completed in 30 sec to 1 min. Finally, an ultrasonic cleaning system was constructed based on the pre-test results. Optimal cleaning conditions of 40 kHz and $50^{\circ}C$ were found in the field test. The productivity and economic efficiency in remanufacturing of laser copy machine are expected to increase by adapting developed ultrasonic cleaning system.

• Economic and Environmental Geology
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• v.57 no.5
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• pp.633-645
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• 2024

Ecosystem services are increasingly recognized for their role in mitigating climate change, particularly through carbon storage and biodiversity. Protecting wetland ecosystems, which are vulnerable to climate change, has become a priority for achieving carbon neutrality. In response, assessment techniques for evaluating wetland value and enhancing carbon sequestration are being developed. Notably, on June 5, 2023, the natural river section of Gapcheon in Daejeon was designated as South Korea's 31st inland national wetland protection area, marking it as the only urban wetland ecosystem in the country to receive such protection. This study evaluates the habitat quality and carbon storage capacity of the Gapcheon Wetland in Daejeon using the InVEST model. To ensure reliability, this study cross-referenced data from the Ministry of Environment's Ecological Zoning Map and the National Ecological Network Map. Additionally, field surveys were conducted to analyze the organic carbon content in the sediment of the Gapcheon Wetland, assessing the applicability of the InVEST model. The habitat quality assessment using InVEST revealed scores ranging from 0.4606 to 0.0787 across different points in the wetland. Soil analysis at 18 sites showed an average organic matter content of 4.28% and organic carbon content of 2.48%, consistent with similar studies on river wetlands. Since InVEST is based on land cover data, classifications may vary depending on the region and survey period. Therefore, to enhance reliability in assessing habitat quality and carbon storage, it is essential to consider factors such as vegetation, non-vegetation environments, and biodiversity. Moreover, the current lack of standardized input data for the InVEST model in South Korea, which relies on foreign research, underscores the need for developing national coefficients and data infrastructure.

• Journal of Veterinary Clinics
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• v.10 no.1
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• pp.111-130
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• 1993

Lead toxicity was evaluated in forty-five cats on a balanced diet, Treated with 0(control), 10, 100(low), 1, 000, 2, 000, and 4, 000(high) ppm of lead acetate orally on a body weight basis. The objectives were to establish toxic dosage level of leaf in cats, to characterize changes in behavior and clinical pathology, and to demonstrate what blood lead concentrations correlate with the known dosages of lead. Some high dose cats showed projectile vomiting, hyperactivity, and seizures. The growth rates did not appear to be altered in any of the dosed groups. Normal blood lead concentration in cats were lower than that of humans, dogs, and cattle. Blood lead concentrations of 3 to 20$\mu\textrm{g}$/100$m\ell$ could be termed a 'subclinical' range in the cat. Clinical lead toxicity in cats may have blood lead concentrations ranging 20 to 120$\mu\textrm{g}$/100$m\ell$. Zinc protoporphyrin concentrations were proportional to lead dosages and a significant ZPP elevation, greater than 50$\mu\textrm{g}$/100$m\ell$, may be indicative of clinical lead toxicity. The enzyme aminolevulinic acid dehydratase showed an inverss dose response relationship for all lead dosages and a significant ZPP elevation, greater than 50$\mu\textrm{g}$/100$m\ell$, may be indicative of clinical lead toxicity. The enzyme aminolevulinic acid dehydratase showed an inverse dose response relationship for all lead dosages and appears to be a good indicator of lead exposure in cats. Urinary aminolevuliruc acid concentrations generally increased with lead dosage, but individual values varied. Hair lead concentrations rose proportionately to lead dosages. Lead at least in high doses appears to inhibit chemotactic activity of polymorphonuclear cells and monocytes. No consistent dose response relationships were observed in hemoglobin, RBC, WBC, neutrophil, lymphocyte, monocyte, and eosinophil counts. There were no consistent dose related changes in total protein, plasma protein, BUN, and ALT values. Reticulocyte counts did not increase significantly in most lead dosage levels, and are probably of little value in diagnosing lead toxicity in cats. The fact that no significant changes were found in nerve conduction velocities may support that there was no segmental demyelination resulting from lead ingestion. The lethal dose in cats appear to range from 60 to 150mg/kg body weight. A reliable diagnosis of lead poisoning can be made utilizing blood lead, ZPP, and ALAD, and hair lead.

• Journal of Information Technology and Architecture
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• v.10 no.4
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• pp.435-449
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• 2013

The performance of Enterprise Architecture (EA) in the Korea's public IT domain produces mixed results and responses. On the one hand, EA earns positive remarks and enthusiasm as a central government-wide IT governance framework with its significant IT budget saving records. At the same time, however, the response to EA at the department and agency level is tainted with disappointment, fatigue, and reluctance. This essay suggests that this is perhaps caused by the sterile lackluster concept of EA Business Architecture employed in the current EA practice of the enterprise. The possibility for liberating and reviving the concept of EA Business Architecture is explored. Various conceptual axes and branches of EA Business Architecture are identified based upon extensive EA field experience and observations, and discussions are made on how the concept of EA Business Architecture can be expanded and amplified on those conceptual axes and branched. The resulting EA Business Architecture conceptualization is consolidated into an illustrative typology for EA Business Architecture. In the end the theoretical and practical implications of the research are discussed along with its contribution and limitation.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.2
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• pp.29-38
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• 2021

According to the theory of concentration recovery(ART), experiencing landscapes with healing properties can heal human mental fatigue caused by intentional concentration. The ART illustrates four healing qualities of the landscape. ART admits that various landscapes can have healing properties, the four healing properties of the landscape explained that the greater the perceptual strength, the stronger the healing effect. Until now, research on healing landscapes has been mainly done on natural and urban landscapes. The purpose of this study is as follows. First, eIt is intended to evaluate the healing characteristics of the Yangdong village landscape using RCS and investigate the impact of the healing characteristics on the visiting preference of the target landscape. Second, Evaluating the landscape image of Yangdong Village landscape, Investigating the effect of landscape images on the healing properties of landscape. This study was conducted in Yangdong Village, Gyeongju, 127 college students participated in the survey. SD 16 items to analyze landscape images and RCS 22 items from Laumann(2001) to evaluate healing properties were used as measurement tools. The findings are summarized as follows. First, The landscape image of Yangdong Village was analyzed through SD method, the analysis of the factors of Yangdong Village landscape image results in two factors: place and singularity. Second, It demonstrates the reliability and validity of RCS, Three factors were extracted from the factor analysis results. Third, Landscape images have a positive effect on the three healing characteristics of RCS. Fourth, Three healing properties of RCS have been shown to have a positive effect on visiting preferences, The order of influence on the relative visiting preferences was analyzed as attractiveness, fit, sense of escape, and sense of space. The findings suggest that future work requires research to re-validate the reliability of RCS. It is also necessary to analyze landscape images for various landscape types to specifically understand the effects on healing characteristics.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.187-199
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• 2016

In order to delineate the soft ground distribution, an integrated geostatistical analysis was performed using the MASW (Multichannel Analysis of Surface Wave) which has the information of overall region and CPTu (Piezo Cone Penetration Test) which provides the direct information of the measuring point of the ground. MASW results were known to have close relationship with the ground stiffness. This correlation was confirmed through the comparison of MASW data obtained from two survey lines to the laboratory test with extracted soil samples. 3D physical property distribution in the study area was acquired by geostatistical integrated analysis with the data of tip resistance ($q_c$) and pore pressure (u) from the CPTu obtained at 6 points within the study area. The integrated analysis was conducted by applying the COSGSIM (Sequential Gaussian Co-Simulation) technology which can carry out the simulation in accordance with the spatial correlation between the MASW results and both tip resistance and pore pressure. Besides the locations of CPTu, borehole investigations were also conducted at two different positions. As a result, the N value of SPT and borehole log could be secured, so these data were used for the analysis of the geotechnical engineering accuracy of the integrated analysis result. For the verification of reliability of the 3D distribution of tip resistance and pore pressure secured through integrated analysis, the geotechnical information gained from the two drilling areas was compared, and the result showed extremely high correlation.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.7 no.1
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• pp.92-109
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• 1996

The objectives of the present study were to provide comprehensive assessment of the impact of epilepsy on the psychological well-being of children with epilepsy and to identify the neurological factors associated with the psychopathology. The participant patients were recruited from the population of children and adolescent aged 7 to 16 attending the OPD of department of pediatric neurology in Seoul National University Hospital in Korea. We exclude mental retardation, pervasive developmental disorder and brain organic pathology. As control group, formal students were chosen and their sex, age, achievement, socioeconomic status were matched to patients. The first author interviewed the children and their family members and obtained the developmental history and family information. We used the following 10 scales for assessing psychological and behavioral problems in patients and their family member. The scales were standardized and their validity and reliability were confirmed before. Parent rating scales : Yale children's inventory, Disruptive behavior disorder scale, Parent's attitude to epilepsy questionnaire, Family environment scale, Symptom check-list-90 revision, Children behavior check-list. Children's self rating scales : Children's depression inventory, Spielberger's state-trait anxiety anxiety, Piers-Harris self-concept inventory and Self-administered Dependency questionnaire for Mother. The result showed the risk factors associated depression were early onset, complex partial seizure, lateralized temporal focal abnormality on EEG, Drug polypharmacy, high seizure frequency and sick factors associated anxiety were old age of patient, lateralized temporal focal abnormality EEG, Drug polypharmacy, high seizure frequency. Also the result of this present study indicated that risk factors associated oppositional defiant disorder, conduct disorder and attention deficit hyperactivity disorder were young age, male, early onset, lateral temporal EEG abnormality and high seizure frequency. According to these results, common risk factors associated psychological and behavioral problems were lateralized EEG temporal abnormality, high seizure frequency in neurological factors.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.34-42
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• 1997

Enuresis is repeated involuntary or intentional voiding of urine into bed or clothes over age 5. Though it would be a self-remitting disorder, it could be serious problem in emotional and socio-adaptational aspects. The author reviewed the enuretic patients of Child & Adolescence psychiatric section in Chungnam National University Hospital during past 3 years. 46(4.9%) of 936 patients were diagnosed as enuresis in DSM-Ⅳ. The author evaluated their comorbidity by the data of diagnostic review made in two psychiatrists, and emotional aspects(self-concept, anxiety, depression) through the self-rating scales (Piers-Harris children’ self concept scales, RCMAS, state-trait anxiety inventory for children, child’s depresson inventory). Thirty(65.2%) of the 46 enuretic patients had additional diagnoses such as attention deficit hyperactive disorder, mental retardation, encopresis, oppositional defiant disorder, depression, anxiety disorder, autism, somatoform disorder, tic disorder, obsessive-compulsive disorder, sleep disorder, etc. Sixteen enuretic patients had at least one comorbid disorder. Eleven patients had two, and three patients had more than three. Fourteen of 46 enuretic patients were evaluated through self-rating scales of self-concept, anxiety and depression. But we couldn’t obtain meaningful results. Maybe it was due to the small sample size(N＝14) and the influence of the comorbid disorders. Finally, it was an impressive evidence that there exist many comorbid disorders in enuresis(esp. attention deifict/hyperactive disorder). In emotional aspects, the author thought that further evaluation should be needed for more meaningful results.

• Analytical Science and Technology
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• v.18 no.6
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• pp.511-519
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• 2005

A method for determination of toluene diisocyanates (TDI) in toluene diisocynate (TDI)-based polyurethane (PUR) packing material was investigated, and also the migration of TDI to food was studied. TDI was extracted using food simulants such as n-haptane and 4% aqueous acetic acid. The determinations were performed using gas chromatography/mass spectrometry (GC/MS). One of major components for polyurethane, toluene diisocyanates, were detected in ten samples among twenty six food contact materials with the concentration range of $0.51{\sim}60.88{\mu}g/ml$. However the highest extracted amount was just 0.7% of $60.88{\mu}g/ml$ if the contact surface of food packing for extracting liquid was limited to the outer layer without exposure of the cutting edge of food packing multi-layers. The result of this study and the analysis method for TDI diisocyanate will be very useful for further study about food contact material, and the monitoring result could be used for evaluating the safety of food contact material before it is to be used for food, preservation.