• Title/Summary/Keyword: 위상(수)학

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Study of Scattering Mechanism in Oyster Farm by using AIRSAR Polarimetric Data (AIRSAR 다중편파 자료를 이용한 굴 양식장 산란현상 연구)

  • Lee Seung-Kuk;Hong Sang-Hoon;Won Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.21 no.4
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    • pp.303-316
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    • 2005
  • Strong radar returns were observed in oyster sea farms, and coherent interferometric pairs were successfully constructed. Tide height in coastal area is possible to be measured by using interferometric phase and intensity of SAR data. This SAR application technique for measuring the tide height in the near coastal zone can be further improved when applied to double bounce dominant areas. In this paper, we investigate the characteristics of polarimetric signature in the oyster farm structures. Laboratory experiments were carried out using Ku-band according to the target scale. Radar returns from vertical poles are stronger than those from horizontal Pole by 10.5 dB. Single bounce components were as strong as double bounce components and more sensitive to antenna look direction. Double bounce components show quasi-linear relation with the height of vertical poles, which implies double bounce is more useful to determine water level than total power. A L-band NASA/IPL airborne SAR (AIRSAR) image was classified into single-, double-bounce, and volume scattering components. It is observed that oyster farms are not always characterized by double bounced scattering. Double bounce is a main scattering mechanism in oyster farms standing above seawater, while single bounce is stronger than double bounce when bottom tidal flats are exposed to air. Ratios of the normalized single to double bounce components in the former and latter cases were 0.46 and 5.62, respectively. It is necessary to use double bounce dominant sea farms for tide height measurement by DInSAR technique.

Airloads and Structural Loads Analysis of LCH Rotor Using a Loose CFD/CSD Coupling (유체-구조 연계해석을 통한 소형민수헬기(LCH) 공력 및 구조하중 해석)

  • Lee, Da-Woon;Kim, Kiro;Yee, Kwan-Jung;Jung, Sung-Nam
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.7
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    • pp.489-498
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    • 2019
  • The airloads and structural loads of Light Civil Helicopter (LCH) rotor are investigated using a loose CFD/CSD coupling. The structural dynamics model for LCH 5-bladed rotor cwith elastomeric bearing and inter-bladed damper is constructed using CAMRAD-II. Either isolated rotor or rotor-fuselage model is used to identify the effect of the fuselage on the aeromechanics behavior at a cruise speed of 0.28. The fuselage effect is shown to be marginal on the aeromechanics predictions of LCH rotor, though the effect can be non-negligible for the tail structure due to the prevailing root vortices strengthened by the fuselage upwash. A lifting-line based comprehensive analysis is also conducted to verify the CFD/CSD coupled analysis. The comparison study shows that the comprehensive analysis predictions are generally in good agreements with CFD/CSD coupled results. However, the predicted comprehensive analysis results underestimate peak-to-peak values of blade section airloads and elastic motions due to the limitation of unsteady aerodynamic predictions. Particularly, significant discrepancies appear in the structural loads with apparent phase differences.

A Study on Korean Seafarers Public Image based on the Q-methodology (Q 방법론을 활용한 우리나라 선원 직업 이미지에 관한 연구)

  • Jo, Sohyun;D'agostini, Enrico
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.2
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    • pp.189-200
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    • 2019
  • Korean seafarers have played a key role throughout the country's history and economic development. They have been a major source of foreign remittance into the nation as well as a pivotal sector in emergency logistics during war times. However, the current number of Korean seafarers in decreasing due to low job attractiveness and retention rate onboard. This is a major problem for the national and international shipping industry as youth seem not to be interested in working onboard for long periods of time. The purpose of this study is to 1) determine what the public opinion about seafarers in Korea is and 2) find out what factors mostly stand out in the public opinion about seafarers profession. The paper suggests that three main types of opinion groups emerged. The first type is labeled as 'high risk, high workload and high stress' as respondents recognized a high possibility of accident onboard and, at the same time, acknowledged that seafarers can be fatigued and stressed. The second type was named as 'Dangerous, Dirty, Difficult', as seafarers' image was mainly associated to fishing vessels and not to merchant and passenger ships. The third type recognized that the social position of the seafarers was low due to 'low social recognition'. The study suggests that all three types have a negative image of seafarers' job. Based on the results of this study, it is necessary to establish various policies and marketing tools to improve the negative job image linked to seafarers by the public opinion. If the public image of seafarers can be improved and attractiveness rose, it is expected a higher number of seafarers will pursue and keep a career at sea.

The Status and the Value of a New Text, Chunghyangjeon(정향전) that Professor Park Sunho Possesses (새 자료 <정향전>의 자료적 특성과 가치)

  • Jang, Si Gwang
    • (The)Study of the Eastern Classic
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    • no.41
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    • pp.211-247
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    • 2010
  • The purpose of this article is to consider the status and the value of a different book of Chunghyangjeon that Professor Park Sunho possesses. Chunghyangjeon that Professor Park Sunho possesses has the text in Chinese and in Korean. Compared with Chullidaebon, Chunghyangjeon that Professor Park Sunho possesses includes deletion, contraction and addition. Chullidaebon has many mistakes while Parkbon in Chinese shows that the mistakes were corrected. According to the standard, Parkbon in Chinese is similar to Mansongbon and Donambon rather than Chullidaebon and it is more similar to Mansongbon than Donambon. In Parkbon in Chinese, hypocrisy of Yangnyeongdaegun is weakened while his negative personality is magnified. And psychological description of Yangyeongdaegun is weakened and Chunghyang's beauty is magnified. Parkbon in Korean shows deletion, contraction, addition, and change. It doesn't show consciousness of lineage and deletes hypocrisy and negative personality of Yangnyeongdaegun. Also, the phrases are being deleted and contracted, which are difficult for those who do not master Chinese literature or Chinese poems. The professor Park Sunho's copy is more significant than other novels circulated at that times, for it is bound along with a copy in Korean. Compared with other editions of Chunghyangjeon and other classical novels circulated, that kind of edition, which included Korean copy, is very peculiar. The Korean-including edition shows that the Chinese literate tried to share the novel with persons who are Korean literate but cannot read Chinese characters.

An Analysis of Operation Structure and Contribution of Civilian Expert Program for Landscape Architects focusing on Local Governments (지방자치단체의 조경분야 민간전문가 제도 운영현황 및 문제점 분석)

  • Park, Jeongeun;Kim, Youngmin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.1
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    • pp.78-90
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    • 2022
  • This research analyzed the status and problems of civilian expert programs for landscape architects to suggest alternatives to improve the current system. Literature research focused on the issues of the legal definition of civilian experts, the background of the program, and related regulations. Based on the understanding of the legal system, the research analyzed the operation status, structure, roles of the civilian expert program of local governments where landscape architects were delegated as civilian experts. Currently, 50 local governments are running the civilian expert program, and landscape architects are working as civilian experts in 11 institutions. The majority of landscape architects are working as MA or general architects. Only SMG runs an independent general landscape architect program. Based on the literature research and interviews with 16 experts, the research examined four main issues related to the program. First, the legal system issues of the civilian expert programs are related to the regulations assuming architects as experts. Revising the current legal system is a better alternative than promulgating a new law for landscape architects. Second, the compensation issue was a main problem related to operation. Securing a sufficient budget and more effective administration is required to solve the problem. Third, related to the role, the tasks being limited to consultation were regarded as the main problem. Although landscape architects wanted more opportunities to directly participate in the project's design, the fairness of the public project contracting system needed to be considered. Fourth, the competence issue is related to the number of available landscape architects. This issue can be solved by expanding the pool of civilian experts to adjacent disciplines, such as public design or landscape management.

Research about Global Positioning of Korean Cosmetic Industry through Trade Network analysis : Focusing on the China-Korea FTA (무역네트워크 분석을 통한 한국 화장품 산업의 국제적 위상에 관한 연구 - 한중 FTA 사례를 중심으로 -)

  • Kim, Yong-Jin;Kim, Young-Jin;Lee, Duk-Hee
    • Korea Trade Review
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    • v.41 no.5
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    • pp.63-87
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    • 2016
  • Despite its rising labor costs these days, China still serves the role as 'World's Factory' thanks to a great deal of foreign direct investment, still remaining one of the world's highest, and the global companies, which have been willingly establishing foreign subsidiaries in China. While enjoying the benefits from the Chinese market, these global companies can now take advantages of another market; the one of Korea. If a product produced by a certain global company is actually manufactured in the local factory in China and the product meets specifications of Rules of Origin, the product shall receive preferential treatment under China-Korea FTA. In the perspective of global market, therefore, it is found that China-Korea FTA may have negative effects on chemical industry in Korea, which is considered one of the representatives of China-Korea FTA. This study examines such risks by network analysis, with several cases of 'Beauty or Make-up Preparations (HS Code 3304).' Analysis shows that Korea is classified as the marginal country group but not main country group when it comes to beauty products family. So this can be a great chance to the global cosmetic companies with local factories in China in the sense that they can increase their sales towards the market of Korea based on the China-Korea FTA. Under these concerns, this study suggests two policy alternatives for the chemical industry in Korea to deal with current challenges rising from China-Korea FTA. The suggested alternatives are: to actively attract the global chemical corporations which are yet to directly enter the Chinese market; and to invest on chemical products with high potential of growth as a priority.

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A study on How to Improve the Work of Professional Landscape Construction in Preparation for the Reorganization of the Production System in the Construction Sector - Based on the Survey Results - (건설분야 생산체계 개편에 대비한 조경분야 전문공사업 업무 개선 방향 - 설문조사 결과를 중심으로 -)

  • Ahn, Myung June
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.3
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    • pp.33-45
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    • 2024
  • The government is promoting the reorganization of the construction indusrty under the theme of reorganizing the production system. However, it has been pointed out that this is contrary to the increasingly specialized and technical skills of the landscaping field. Therefore, it is urgent to respond to the construction industry integration policy and improve an appropriate work system and the content of the landscape field. Therefore, this study investigated the intention of the industry to reorganize the production system and the production structure of the landscape field, so that it can be used as a reference for future changes. As a result of the survey, 1) the perception of the reorganization policy is a highly requesting step-by-step promotion that reflects the industry's will, 2) the system is divided into generalization and specialization and is highly opposed to integration, 3) appropriate design and construction costs are the most important directions for improving landscape construction projects, and 4) reestablishing the relationship with related civil engineering works is important for improving detailed construction types. Overall, it was pointed out that the current specialized landscape construction does not sufficiently reflect the changing landscape business and is only appropriate for subcontractors in other industries. Therefore, it is necessary to promote policies that reflect this. In the long run, it is urgent to establish the status of landscape construction as an independent object, and it is necessary to supplement the legal system and change the industry accordingly.

$^{18}F$-FDG Colonic Uptake by Oral Anti-Diabetic Drugs Including Metfomin in PET/CT Scan (PET/CT 검사에서 Metformin 성분의 항 당뇨약제에 의한 대장에서의 $^{18}F$-FDG 섭취에 관한 연구)

  • Kim, Sang-Gyu;Park, Hoon-Hee;Kim, Jung-Yul;Bahn, Young-Kag;Lim, Han-Sang;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.50-54
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    • 2010
  • Purpose: The uptake of $^{18}F$-FDG is often observed in normal cell of colon to patients who have non-insulin-dependent diabetes mellitus and had taken anti-diabetic drugs including Metformin in PET/CT scan. In this study, the region of colon was compared between the patients who took anti-diabetic drugs including Metfomin and other patients who took the other anti-diabetic drugs through SUV measurements. Materials and Methods: A hundred eighty patients were studied. 120 patients who have non-insulin-dependent diabetes mellitus (Including Metformin: 60, Excluding Metformin: 60) and 60 patients as a control group were composed. The patient fasted at least 6 hours before receiving an intravenous injection of 370-592 MBq (10-16 mCi) of $^{18}F$-FDG. Scanning from the base of the skull though the mid thigh was performed using the Discovery STe PET/CT Equipment (GE Healthcare, Milwaukee, WI, USA). The highest uptake region was measured SUV among ascending, transverse and descending colon. Results: The values of patients who took the anti-diabetic drugs including Metformin were $6.16{\pm}3.64$ g/mL, $4.41{\pm}2.94$ g/mL, and $5.46{\pm}2.44$ g/mL. The patients who took the anti-diabetic drugs which does not have Metformin were $3.05{\pm}1.39$ g/mL, $2.08{\pm}0.97$ g/mL and $3.15{\pm}1.85$ g/mL. The control group were $2.02{\pm}0.88$ g/mL, $1.68{\pm}0.87$ g/mL and $2.19{\pm}1.88$ g/mL. Conclusion: The effect of the intake of Metformin was observed from the SUV on region of large bowel in this study. Thus, it could be helpful for the results by identifying the ingredient of anti-diabetic drug before the examination and the possibility of interpretation of false positive will be reduced.

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A Study on the Record Management of National Archives of Korea (국가기록물 관리의 현황에 관한 발전적 제언)

  • Kim, Sung-Soo
    • Journal of Korean Society of Archives and Records Management
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    • v.3 no.1
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    • pp.159-184
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    • 2003
  • In this research the issues of record management of national archives in Korea are classified into four categories: 1) improving the status of the Central Archives of Korea, 2) constructing a new national archives, 3) revising the law on the record management, 4) creating qualifications for a professional administrator for Archivist. 1) In order to strengthen the function of the Central Archives of Korea, it is very urgent to create a systematic mechanism in which the Central Archives oversees and administers public archives(documents) collected from all the public institutions not only under the Administration but also the legislature and the judicial authorities. 2) This paper suggests that a new National Archives should be a symbolic building representing Korea as archives. Considering the fact that Presidents archives will be a part of this new National Archives, it also suggests that artistic and decorative pieces which embody Korea's representative archives or people should be included in the building. The budget for these should be supplied by the government. 3) This paper looks at the matter of revising the law on Record Management in two respects: (1)strengthening the function of the Central Archives of Korea, (2)making it obligatory to produce archives not open to the public, or making a protection clause for secret archives. This paper proposes that the Central Archives of Korea will be able to collect all the public archives from all the public institutions, and to oversee and administer them by revising the 5th and 6th clauses of the current law on the record management. It also proposes that some laws which make it obligatory to produce archives for documents not open to the public, and which protect those secrecy. 4) Regarding the qualifications for a professional administrator for the record management, this paper suggests lowering the qualification a little to the bachelor's degree of the record management. Also it suggests taking into consideration the persons in charge of the record management in public institutions and acknowledging their qualifications after a certain period of training at the Central Archives of Korea or something like that. In addition, it classifies the ranks of the professional administrators according to their qualifications.

Research on the Actual Condition of the radiation Safety Management(RSM) for the Educated Training of the Dental Diagnostics X-ray Generators (교육용 치과 엑스선 발생장치에 대한 방사선 안전 관리 실태 조사)

  • Lee, Mihyeon;Yu, Yunsik;Lee, Jaeseung;Im, Inchul
    • Journal of the Korean Society of Radiology
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    • v.8 no.7
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    • pp.467-477
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    • 2014
  • The purpose of this study is to offer data base for establishment of dental training x-ray generator based safety usage through surveying real radiation safety management state of radiation worker's in plan of operations that have dental training x-ray generators and use it. For it, comprehensive references were surveyed referring reports of current state of regulation technique development and domestic radiation safety evaluation and nuclear related legislation regarding radiation safety management of dental training x-ray generators. On the basis of it, questionnaires were filled in about respondent's general characteristic radiation safety manager's status current state of radiation safety management and the level of knowledge & consciousness. For the study, the survey was conducted to 224 people of radiation safety managers and university graduates training assistants and full-time professors who can treat dental training x-ray generators in education center. through this survey 95 questionnaires were used as analysis materials except the insufficient and omitted responses. As a method of analysis, the frequency and percentage were figured out with the general characteristics and safety manager's status. Chi-square test for frequency and correlation per question analysis and Pearson correlation analysis for crosslevel correlation were done with current state of radiation safety management and knowledge & consciousness level. As a result, running dental training x-ray generators was dealt with by 20's to 40's who have high education level over post undergraduate degree and major in dental hygienic. In addition, female have higher consciousness level for radiation safety management than male. It shows significal linear relation statistically(${\chi}^2$ >5, 0.1${\chi}^2$ >5, 0.3${\chi}^2$ >5, 0.3