• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.1
• /
• pp.103-113
• /
• 2020

Jack-up drilling rigs are widely used in the offshore oil and gas exploration industry. Although originally designed for use in shallow waters, trends in the energy industry have led to a growing demand for their use in deep sea and harsh environmental conditions. To extend the operating range of jack-up units, their design must be based on reliable analysis while eliminating excessive conservatism. In current industrial practice, jack-up drilling rigs are designed using the working(or allowable) stress design (WSD) method. Recently, classifications have been developed for specific regulations based on the load and resistance factor design (LRFD) method, which emphasises the reliability of the methods. This statistical method utilises the concept of limit state design and uses factored loads and resistance factors to account for uncertainly in the loads and computed strength of the leg components in a jack-up drilling rig. The key differences between the LRFD method and the WSD method must be identified to enable appropriate use of the LRFD method for designing jack-up rigs. Therefore, the aim of this study is to compare and quantitatively investigate the differences between actual jack-up lattice leg structures, which are designed by the WSD and LRFD methods, and subject to different environmental load-to-dead-load ratios, thereby delineating the load-to-capacity ratios of rigs designed using theses methods under these different enviromental conditions. The comparative results are significantly advantageous in the leg design of jack-up rigs, and determine that the jack-up rigs designed using the WSD and LRFD methods with UC values differ by approximately 31 % with respect to the API-RP code basis. It can be observed that the LRFD design method is more advantageous to structure optimization compared to the WSD method.

• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.145-153
• /
• 2013

It is a global trend that the water management policy is shifting from a water quality-oriented assessment to the aquatic ecosystem-based assessment. The majority of aquatic ecosystem assessment systems were developed solely based on physicochemical factors (e.g., water quality and bed structure) and a limited number of organisms (e.g., plankton and benthic organisms). Only a few systems use plants for a health assessment, although plants are sensitive indicators reflecting long-term disturbances and alterations in water regimes. The development of an assessment system is underway to evaluate and manage lakes as ecosystem units in the Korean Ministry of Environment. We reviewed the existing multivariate health assessment methods of other leading countries, and discussed their applicability to Korean lakes. The application of multivariate assessment methods is costly and time consuming, in addition to the correlation problem among variables. However, a single variable is not available at this moment, and the multivariate method is an appropriate system due to its multidimensional evaluation and cumulative data generation. We, therefore, discussed multivariate assessment methods in three steps: selecting metrics, scoring metrics and assessing indices. In the step of selecting metrics, the best available metrics are species-related variables, such as composition and abundance, as well as richness and diversity. Indicator species, such as sensitive species, are the most frequently used in other countries, but their system of classification in Korea is not yet complete. In terms of scoring metrics, the lack of reference lakes with little anthropogenic impact make this step difficult, and therefore, the use of relative scores among the investigated lakes is a suitable alternative. Overall, in spite of several limitations, the development of a plant-based multivariate assessment method in Korea is possible using mostly field research data. Later, it could be improved based on qualitative metrics on plant species, and with the emergence of further survey data.

• Journal of Korea Port Economic Association
• /
• v.30 no.3
• /
• pp.163-185
• /
• 2014

The growth of a city requires substantial resources, an appropriate environment, and the alignment of several factors. City growth also evolves through changes in its history, culture, economics, societies, groups, and government systems. However, current port city development plans designed to encourage the growth of local businesses fail to provide the support needed for both the city and businesses. The recent actions of urban administrations and federal and local governments have revealed that they have yet to create a mature decentralized management system, or perhaps have ignored the reality of needing one. Taking a clear look at the differences between port regions, such as Gwangyang and Pyeongtaek, and understanding their effect on city growth would be a prudent course of action when preparing for future developments. The purpose of this study is to determine the relationship between ports and cities by analyzing the effect of port characteristics on nearby city growth. This study used a comparison analysis to determine how port characteristics affected the growth of Pyeongtaek and Gwangyang. One result of this analysis showed that an increase in the number of goods being imported or exported had a positive effect on the growth of both port cities, In this respect, an aggressive plan and cooperation between the federal and local government should occur simultaneously. Furthermore, efficient local policies that focus on the increase of personnel and material resources should be pursued as a standard strategy, which would also promote the international status of these locations. The results of this study show the importance of government cooperation. The federal government should lead with aggressive strategies that aim to optimize efficiency, while the local government should provide the necessary assistance and coordination in order to achieve optimal results.

• Journal of Korean Society of Forest Science
• /
• v.98 no.6
• /
• pp.791-798
• /
• 2009

The role of forest and soil carbon under global climate change is getting important as a carbon sink and it is necessary to research on applicable forest models as well as in the field for a study of these dynamics. On this study, historical annual litter dataset as a major input data for the forest soil carbon model, Yasso was established using a dendrochronological reconstruction method, and the soil carbon dynamics of a Pinus densiflora forest in Gwangneung, Korea was simulated using Yasso. The amount of litter (needle, branch, stem and fine root) production, which was estimated using the dendrochronological method, has increased continuously from 1971 to 2006. Furthermore, there was no significant error between estimated and measured values of litter production (needle and branch) in 2006. The average of simulated soil carbon stock up to 30 cm depth was $46.30{\pm}4.28tCha^{-1}$, which accounted for 53% of carbon stock in trees of the forest, and had no significant difference and error with measured soil carbon stock. Under the climate change trend in Korea according to IPCC A1B scenario, it was estimated that the simulated soil carbon stock in the region would increase continuously from 1971 to 2041 and then decreased until 2100. Compared to the result of the scenario that there is no climate change, the soil carbon stock could be decreased up to 7.58% at 2100. It was inferred the dendrochronological reconstruction method and simulation of Yasso model are useful to estimate soil carbon dynamics of the natural P. densiflora forest. Follow-up researches, such as improvement of the dendrochronological method and Yasso model and their application and validation in various environment, are needed to produce more reliable results.

• Journal of the Korean Geographical Society
• /
• v.40 no.6 s.111
• /
• pp.748-761
• /
• 2005

This study attempts to describe and periodinate the sixty years history of Korean Geographical Society. For the purpose, several numerical records concerned with the society were employed. The Korean Geographical Society was established in 1945 as a first academic society in geography. The international participation of Korean geographers started when it applied for the IGU membership in 1959. Next year, Korean's application was approved at the 19th IGC in Stockholm. The 40 years later, Korea came to host the 29th IGC in Seoul. This means that the activity of Korean geographers has been vigorous during the 40 years in accordance with high growth of Korean economy. The number of the society member reached 116 in the latter part of 1960s. It grew steadily from 1970s to 1990s and now amounts to around one thousand. It is believed that such trend is associated with the increase of geographical department and the development of graduate programs during past 40 years in Korea. The number of the advanced degree holders was only 2 in 1960, and now reachs 338 among which 166($43\%$) obtained from the foreign country. The Int issue of the society journal 'Geagraphy' -the title was changed to 'Journal of the KGS' in 1993-was published in 1963. It has gradually developed into the annual for $1966{\~}1973$, the semi-annual for $1974{\~}1990$, the quaterly for $1991{\~}1997$, and the hi-monthly until 2005. One issue per year has been published in English since 1993. The annual number of papers accepted by the editorial board has increased from 7 in 1960s-1970s to 52 in the new millennium. In terms of the specialty distribution of total 725 papers after 1963, many Korean geographers have been preferable to the field of socio-economic and urban geography as their major, and next histro-cultural and physical geography. Recently, a growing number of younger geographers are more interested in such diversified fields as ecological geography, socio-historical geography, applied geography concerned with GIS technic, geography education and so on. Such trend is a reflection of the new era which is characterized by diversity, software, high technology, globalization and others. The sixty years history of the society nay be summarized into the five phases of periodization: (1) establishment and chaos($1945{\~}1959$), (2) reconstruction(1960${\~}$1969), (3)reorganization(1970${\~}$1989), (4) jump and rush($1990{\~}1999$), (5)globalization($2000{\~}\;$).

• Land and Housing Review
• /
• v.8 no.4
• /
• pp.233-247
• /
• 2017

In Europe and the USA, the use of limit state design method has been established, and the Korea Ministry of Land, Transport and Maritime Affairs has implemented the bridge substructure design standard based on the critical state. But Korean piling methods and ground conditions are different from Europe and USA, the limit state design method can not be used immediately. In this study, the resistance coefficient was proposed by comparing and analyzing the results of the static load test(9 times) and dynamic load tests(9 times of EOID and 9 times of Restrike) with the bearing capacity calculated by Meyerhof(LH design standard, Road bridge design standard) method and surcharge load method(using Terzaghi's bearing capacity coefficient and Hansen & Vesic's bearing capacity coefficient). The previous LHI study showed the resistance coefficient of the LH design standard was 0.36 ~ 0.44, and this research result showed the resistance coefficient was 0.39 ~ 0.48 which is about 8% higher than the previous study. In this study, we tried to obtain the resistance coefficient mainly from the static load test and the resistance coefficient was 0.57 ~ 0.69(Meyhof method : LH design standard) based on the ultimate bearing capacity and the resistance coefficient was 0.49 ~ 0.60(Meyhof method : LH design standard) based on the Davissons bearing capacity. The difference of the resistance coefficient between the static and dynamic load test was greater than that we expected, we proposed the resistance coefficient(0.52 ~ 0.62 : Meyerhof method: LH design standard) using the modified bearing capacity of the dynamic load test. Summarizing the result, the coefficient of resistance obtained from the static and dynamic load tests was 0.35 ~ 0.76, which is greater than 0.3 suggested by the Road bridge design standard, so the economical design might be possible using the coefficient of resistance proposed by this study.

• Journal of Distribution Research
• /
• v.15 no.5
• /
• pp.103-126
• /
• 2010

The development of an industry including distribution sector is influenced by not only government policy but the related firms' behaviors. Recently the large-scale retailers have had more enormous channel power than any other distributors including monopolistic makers. Now is the time for government to prepare some policies against the unfair transaction behaviors by large-scale retailers. In this paper I tried to inquire into the distribution competition policy from a political correspondent point of view related with the transition of distribution system. For the purpose of this article I compared the case of Korea with Japan. According to the results so far inquired, there are some commons and differences in the cases of the two. Some suggestions are as follows. Considering the predominant position the concept of large-scale retailers is to be extended from a single store to numerous chain stores in the political level. Government needs to examine the standard propriety for large-scale retailer; the size of selling area and amount of sales a year. When a large-scale retailer store is to be established, it need to be taken a permit or a pre-inspection. The Fair Trade Commission have to secure the neutrality from Government's strategies. And government should find out the examples of unfair transaction behavior types and prepare some proper guidelines continually. For the last time statistical data by distributors are to be fitted out and the actual investigations for estimating the effects of government policies need to be enforced.

• Journal of Veterinary Clinics
• /
• v.26 no.6
• /
• pp.556-562
• /
• 2009

Skin tumors and mammary gland tumors have been shown to be the most common neoplasia in most of the strains of dogs. The risk for tumor development increases significantly with age and the prevalence and distribution are various according to individual tumors. The aim of this study is to classify histopathologically the skin and mammary gland tumors for recent two years, 2005 and 2006. A total of 128 skin and 240 mammary gland samples of dogs were selected that were submitted to National Veterinary Research and Quarantine Service and Kangwon National University from January 1, 2005 to December 31, 2006. The excised tissue were fixed in 10 percent neutral buffered formalin and processed routinely to paraffin wax. Sections were cut at $3{\mu}m$, stained with haematoxylin and eosin. The slides were examined based on the morphological criteria of M. H. Goldschmidt and W. Misdorp under a light microscope. The age of the dogs ranged from 1 to 19 years with a median of 8.7 years. The mean age of the skin and mammary gland tumors was 7.4 and 9.3 years. 47 (12.8%) were males and 259 (70.4%) were female with a male to female ratio of 0.18. Yorkshire terrier and maltese were more susceptible breeds, accounting for 44.3% of skin and mammary gland tumors. In skin tumors, epithelial, adnexal, and mesenchymal origin tumors were 18 (14.1%), 53 (41.4%), and 57 cases (44.5%), repectively. Among the epithelial, adenexal, and mesenchymal origin tumors, basal cell tumor (8.6%), sebaceous adenoma (15.6%), and histiocytoma (25.0%) were predominant in the incidence rate, respectively. In case of mammary gland tumors, 201 (83.8%) were benign and 39 (16.3%) were malignant with a benign to malignant ratio of 5.15. The most frequent mammary gland tumor was benign mixed tumor (35.0%) followed by mammary adenoma-complex type (31.7%).

• The Korean Journal of Air & Space Law and Policy
• /
• v.28 no.1
• /
• pp.55-71
• /
• 2013

By aircraft from Aviation regulations and institutional regulatory framework for ensuring the safety is secured. State-of-the-art aircraft, according to the type of development and diversification, modernization and new types of aircraft are operated. In particular, light aircraft and ultralight flying device such as the gyro-plane and unmanned flying devices is introduced a new device, and the device operates at these flight in accordance with the standards of the Aviation Act regulations may not occur often. Variety of light aircraft and ultra-light aircraft assembly, can be adapted for a person engaged in the business of aviation safety management and to perform the legal basis was established. Depending on the classification of newly introduced aircraft, the biggest change is the introduction of the concept of the LSA. In Korea, the various light aircraft are operating, but these aircraft range not clearly Aviation Regulations had difficulty in ensuring safety. This study examined the differences between international rules and regulations of Korea about the classification of aircraft. The LSA are included in aircraft categories internationally, but LSA will not be included in the aircraft categories, which is one of a range of powered flight device exists in Korea Aviation Act. Limit for maximum continuous power speed in a LSA, it is a limit on the right of the people who want using the high-performance plane. Also it is an international trend does not fit in, and is consistent with the intent of LSA manufacturer. Delete the content from a range of future aviation law revisions and light aircraft-related provisions to limit the maximum continuous power speed is considered to be suitable for the purpose of introducing the light aircraft industry. The laws and regulations set up in order to ensure the safety of ultralight aircraft categories existing in ultralight aircraft that exceeds the purpose of the introduction of LSA technology development at home and abroad, and is intended to reflect. These standards complement of aircraft operation is not appropriate for the situation unless the country is difficult to ensure the safety of operations. Also developed in other countries, the introduction of aircraft operating in the country, so many problems occur early revision is required.

• The Korean Journal of Air & Space Law and Policy
• /
• v.33 no.1
• /
• pp.227-260
• /
• 2018

Recently, as the use of drones increases, the risk of drone accidents and third-party property damage is also increasing. In Korea, due to the recent increase in drone use, accidents have been frequently reported in the media. The number of reports from citizens, and military and police calls regarding illegal or inappropriate drone use has also been increasing. Drone operators may be responsible for paying damages to third parties due to drone accidents, and are liable for paying settlements due to illegal video recording. Therefore, it is necessary to study the idea of providing drone insurance, which can mitigate the liability and risk caused by drone accidents. In the US, comprehensive housing insurance covers damages caused by recreational drones around the property. In the UK, when a drone accident occurs, the drone owner or operator bears strict liability. Also, in the UK, drone insurance joining obligation depends on the weight of the drones and their intended use. In Germany, in the event of personal or material damage, drone owner bears strict liability as long as their drone is registered as an aircraft. Germany also requires by law that all drone owners carry liability insurance. In Korea, insurance is required only for "ultra-light aircraft use businesses, airplane rental companies and leisure sports businesses," where the aircraft is "paid for according to the demand of others." Therefore, it can be difficult to file claims for third party damages caused by unmanned aerial vehicles in personal use. Foreign insurance companies are selling drone insurance that covers a variety of damages that can occur during drone accidents. Some insurance companies in Korea also have developed and sell drone insurance. However, the premiums are very high. In addition, drone insurance that addresses specific problems related to drone accidents is also lacking. In order for drone insurance to be viable, it is first necessary to reduce the insurance premiums or rates. In order to trim the excess cost of drone insurance premiums, drone flight data should be accessible to the insurance company, possibly provided by the drone pilot project. Finally, in order to facilitate claims by third parties, it is necessary to study how to establish specific policy language that addresses drone weight, location, and flight frequency.