• Journal of Ocean Engineering and Technology
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• v.30 no.1
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• pp.32-43
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• 2016

A UUV needs to have a robust path following performance because of unpredicted current disturbances. Because the desired path of a UUV is usually designed by considering the locations of obstacles or geographical features of the operation region, the UUV should stay on the desired path to avoid damage or loss of the vehicle. However, conventional path following methods cannot deal with strong countercurrent disturbances. Thus, the UUV may deviate from the desired path. In order to avoid such deviation, a backward path following method is suggested. This paper proposes a path following method that combines pure pursuit guidance and nonlinear guidance for the UUV under an unpredicted strong ocean current. For a stable path following system, this paper suggests that the UUV adjust its heading to the current direction using the pure pursuit guidance method when the system is in an unstable region, or the UUV follows the desired path with nonlinear guidance. By combining the pure pursuit guidance and nonlinear guidance, it was possible to overcome the drawbacks of each path following method in the reverse path following case. The efficiency of the proposed method is shown through simulation results compared to those of the pure pursuit method and nonlinear guidance method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1553-1558
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• 2014

The travel demand, peak hour ratio and forms of platform of urban railway stations are very different each other, also the users' behavior is. So the types of urban railway stations have to be classified according to these characteristics. However, the current methods of classification are arbitrary on the purpose of each studies and the legal standards are very simple; categorized by normal station vs. whistle station, types of trains, forms of platforms and shapes of architecture. This study clarifies the standards for classifying the types of urban railway stations, results the complete enumeration survey on all the urban railway stations in Seoul Metropolitan Area and makes the database based on the surveyed data, purposing on helping for making strategies and researching. On this study, utilizing the database which is established for this study, the correlation between the physical and geographical characteristics and users' travel patterns of urban railway stations is clarified by the statistical analysis. In the future, the statistical results will be helpful for making strategies and researching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4601-4610
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• 2014

Photography has been a way of recording a range of images throughout the previous 160 years since its birth in 1839. It has also included the observations and records on the subjects, which is almost same as reality in its outward appearance, various looks of a city and architecture in the daily lives at these places. These pictures provide archaeological and geographical information beyond time and space as well as expressing cultural and artistic images using the creative senses. This thesis analyzes the images of a city and architecture as various angles along with development process of the photograph. The purpose is to examine what viewpoints, methods and concepts have been used to observe the city and architecture. The study will show that photography is a means of artistic expression and a means of indirect understanding of a city and its architecture by early modern photography of the 19th Century.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.153-164
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• 1997

This study was conducted to develop the new Environmental Impact Assessment techniques for the grading of rareness in plant. 17 EISs which were submitted in 1996 were analyzed to know the problems in existent EIA techniques for the conservation of rare plants. Category of rare plant was reevaluated and evaluation technique for the grading of rareness in plant was developed. The results obtained from this study were as follows: 1. The evaluation technique of rareness in plant was not reflected in the current preparation provision for EIS. And t his fact also appeared in most of the EIS which were reexamined in this study. 2. The category of rare species which have been considered as the subject of protection in EIA have to be enlarged to more than legally protected species designated by MOE. 3. The taxonomic characteristics and status of species, characteristics of population, geographical characters, extent of threat and its possibility by man resulted from the habitat loss were investigated. Each item was endowed scores from 1 to 5 and all the scores were summed, and then this value was used to evaluate the order of conservation. 4. Conservation measures for the rare plants have to be applied according to the levels of rareness grade, and they are absolute conservation, in situ conservation, transplanting and ex situ conservation, post observation and none by the levels from A to E. 5. Considering the phenology of rare plants, investigation for the rare plants have to be made a1 least three times. 6. Size of the MVP(Minimum Viable Population), pollination ecology also have to be considered for the conservation of rare plants. And in the case of adopting ex situ conservation measure, the site and methods for the conservation of rare plants have to be proposed in detail.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.5
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• pp.101-109
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• 2009

There are increasing needs about creation and sustainable management of urban forest for environmental conservation and recreational service for citizen. However, it is difficult for local governments to create or manage urban forest in recreational or conservational way. The purpose of this study is to classify the urban forest types by considering its geographical feature, biological and sociological characteristics in order to suggest a guide to local governments about effective creation or management of urban forest. In this study, we extracted common characteristics of the selected five indicators. Factors about urban forest are divided into two groups. Factors were named according to the variables as 'Urban Forest Naturalness', and 'High Accessibility and Disturbed by Human.' In addition, we classified urban forests into four types in this study. The type I of urban forest is a large forest and has high naturalness such as Mt. Bukhan and Mt. Gwanak. The type II is fragmented to large forests by developmental projects. The type III is flat and has high accessibility such as forest behind Seonjeongneung. The type IV is located near residential area such as Mt. Ansan, Mt. Inwang and Mt. Bonghwa. It is possible to set up recreational area for citizens and ecological networks for species by the research of the urban forest type. The results of the study, classification of urban forest types and its application, contribute to provide a guide for local governments to create or manage urban forests effectively.

• Journal of Environmental Health Sciences
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• v.38 no.2
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• pp.95-104
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• 2012

Objectives: The goal of this study was to investigate the relationships between proximity to an industrial complex and blood lead levels and urinary cadmium levels. Methods: We conducted a questionnaire survey and analyzed blood lead and urinary cadmium levels using Atomic Absorption Spectrometry (AAs). Data was analyzed using logistic regression analysis. All statistical analyses were conducted with SAS software version 9.2. The distance between the residence and an industrial complex was calculated through a Geographical Information System (GIS). Results: A total of 967 residents living near a large petrochemical complex in Ulsan participated. The geometric mean levels of blood lead and urinary cadmium were $1.70{\mu}g/dl$ (male: $1.77{\mu}g/dl$, female: $1.67{\mu}g/dl$), and $0.72{\mu}g/g$ creatinine (male: $0.49{\mu}g/g$ cr. female: $0.89{\mu}g/g$ cr.), respectively. Blood lead and urinary cadmium levels both increased with age and were higher among smokers compared to never smokers. Both significantly showed a decreasing trend with rising income. Results from multiple logistic regression analysis showed that urinary cadmium levels for subjects aged less than 20 years old were negatively associated with distance from the industrial area to the residence. The results, however, indicated that the blood lead levels were positively associated with the distance. Conclusions: The results of this study support that proximity to an industrial complex is related to urinary cadmium values for children. A positive finding with blood lead can be explained by the ambiguity of lead exposure sources in the general environment.

• Journal of IKEEE
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• v.16 no.1
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• pp.7-14
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• 2012

In this paper, a reception rate of terrestrial digital TV broadcasting service is analyzed and a novel method which can estimate the broadcasting coverage rate more objectively and reliably than the existing method is proposed. Previous method measures the reception rate by means of electric field intensity measurement or subjective video quality assessment. Because of limited measuring points, it inherently has measurement error and cannot consider the viewer's receiving conditions in real-time. In order to consider the viewer's population and receiving environment, morphology which characterizes the viewer's receiving environment is extracted using household census data of National Statistical Office and the land cover map of Ministry of Environment. Using the extracted geographical morphology, the reception rate of terrestrial digital TV broadcasting service is calculated with Spectrum Management Intelligence System (SMIs). Proposed method can calculate the reception rate more objectively and reliably than the existing methods because it fully considers the viewer's receiving environments in real-time.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.429-438
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• 2020

Objectives: Given that Argentinian public-sector workers are highly exposed to stressful conditions, and that the psychometric properties of the widely used Perceived Stress Scale (PSS) should be evaluated in different settings, this work aimed to compare the psychometric properties of the Latin American Spanish PSS-10 and PSS-4 and to identify the optimal scale for stress assessment. Methods: A sample of 535 participants was randomly divided into 2 groups to evaluate dimensionality by exploratory and confirmatory factor analyses. The reliability of both scales was also evaluated. Convergent validity was estimated using the Executive Complaints Questionnaire, the average variance extracted, and the composite reliability. Discriminant validity was based on the correlation with the Utrecht Work Engagement Scale and the phi-square correlation between the components. Results: The factor analyses supported bidimensionality of the PSS-10 (stress and coping), which showed a better fit than the PSS-4. Moreover, the reliability of the PSS-10 was higher, whereas the PSS-4 did not achieve adequate values of internal consistency. The PSS-10 was also correlated significantly with all validation scales, and presented proper internal convergent and divergent validity. Conclusions: The PSS-10 is a reliable and structurally valid instrument to measure perceived stress and coping in a Latin American Spanish-speaking population with high work demands, and the findings of this study expand our knowledge on the geographical and sociocultural applicability of the PSS.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.143-154
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• 2005

This paper proposes the location acquisition methods and LBS(location-based services) system using RFID(radio frequency identification) tags with location information in ubiquitous city. Location information is checked using RFID tags attached to various buildings. stores and road signs. And various LBSs are provided based on the location information. Traditionally, when the location information is obtained by a GPS, the precision of the location information may deteriorate due to geographical displacement of a satellite and GPS receivers, for example shadow zone by building, in-door environment, and heavy cloud. The objective of this paper is to provide a ULID(universal location identification) data structure, a ULID-based location acquisition method and an LBS system, in which precise location information is extracted using RFID tags attached to various buildings, stores and road signs and ULID and also danger of information leakage is minimized so that an LBS of ubiquitous environment can be provided to a user.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7219-7229
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• 2015

Background: Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions. Materials and Methods: In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR. Results: Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes. Conclusions: These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.