• 한국압력기기공학회 논문집
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• 제16권1호
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• pp.42-48
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• 2020

The effect of improving the tensile and J-R fracture toughness properties of SA508 Gr.1a on the LBB margin for the main steam pipe is investigated. The material properties and microstructure images of the existing main steam piping material SA106 Gr.C used in domestic nuclear power plants and the newly selected material SA508 Gr.1a were compared. For each material, LBB margins were calculated and compared through finite element analysis and crack instability evaluation. The LBB margin of the improved SA508 Gr.1a is found to be greatly improved compared to that of the existing SA106 Gr.C and SA508 Gr.1a. This is because of the increased material's strength and J-R fracture toughness compared to the previous materials. In order to analyze the effect of physical property change on the LBB margin, the sensitivity of each LBB margin according to the variation of tensile strength and J-R fracture toughness was analyzed. The effect of the change in tensile strength was found to be greater than that of the change in fracture toughness. Therefore, an increase in strength significantly influenced the improvement of the LBB margin of the improved SA508 Gr.1a.

• 한국물환경학회지
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• 제30권3호
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• pp.351-360
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• 2014

The allocation of margin of safety (MOS) at a uniform rate to all areas of the unit watershed makes it very difficult to keep the load allotment stable in the area for lack of reduction measures like forest land. This study developed an equation to calculate margin of safety differentially according to the regional characteristics. The equation was formulated on the basis of the regional characteristic factors such as a load contribution factor for land use type and a site conversion factor for the unit watershed. The load contribution factor represents a contribution of loads from a particular land use. The site conversion factor was derived from the site conversion ratio of a unit watershed. Margin of safety for the non-point pollution load in the land use sector decreased by 20~25% in three river basins. The margin of safety in the unit watersheds with low site occupation ratios decreased in high rate, while in the unit watersheds with large urban area decreased in low rate. With the application of the differential margin of safety considering regional characteristics, not only the reduction of pollution loads can become lighter but also it can be easier to develop plans for Total Maximum Daily Loads (TMDLs) even where the reduction measures are not available.

• 자원환경지질
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• 제27권6호
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• pp.571-577
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• 1994

미국 대서양 대륙주변부는 북미와 아프리카 대륙의 중생대 분열의 산물로서 화산성 기원 혹은 비화산성 기원인가에 대해 논란이 있어 왔다. 이를 규명하기 위하여 미국 남동부 해안에서 채취한 다채널 탄성파 단면도에 나타난 기반암들의 영상을 조사하였다. 가장 핵심적인 탄성파 영상의 하나는 전체적으로 쐐기 형상을 보이는 해양방향의 경사반사층들(seaward-dipping reflectors; SDR)이다. 이들은 화산성 열개주변부의 상징적인 기반암 구조로 알려져 있다. 연구지역에는 2 개조의 해양경사층 쐐기구조가 존재하였다: 하나는 기반암 경첩대 (basement hinge zone) 부근이고 ('the hinge SDR wedge'라고 명명), 다른 하나는 미국 동해안 자기이상대 (the East Coast magnetic anomaly)의 바다 쪽에 위치한다 ('the outer SDR wedge'라고 명명). 또한, 기반암 경첩대의 동쪽 지각에서는 "7.2 km/s 층"으로 알려진 높은 속도의 하부지각층과 함께 원만한 기복의 모호 불연속면 등이 관찰되었다. 이러한 기반암 구조와 잘 알려진 화산성 기원의 대륙주변부의 지각구조를 비교해 보아 미국 남동부 대륙주변부를 화산성 기원의 대륙주변부로 특징지었다.

• Journal of Korea Trade
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• 제25권1호
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• pp.89-111
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• 2021

Purpose - The U.S. Trade Preference Expansion Act (TPEA) of 2015 enables the US Department of Commerce (DOC) to inflate dumping margin when the particular market situation (PMS) exists in the exporter's home market. DOC applied PMS provisions to the steel products from Korea. This paper analyzes whether DOC's calculation by using the regression analysis is consistent with WTO rules. Design/methodology - This paper analyzes the PMS application in law and regression analysis that extends the data period from 10 years to 18 years using the same economic model with DOC, and changes the country group according to the quantities of steelmaking capacity. Findings - Results show that DOC's argument conflating the sales-based with cost-based PMS designed to inflate dumping margins might not be consistent with WTO Antidumping Agreement Article 2.2 and 2.2.1.1 in which costs shall normally be calculated on the basis of records kept by the exporter, providing generally accepted accounting principles and reasonably reflection of the costs and PMS that exists in the Korean steel product markets. Even if it will be consistent, DOC's calculated margin by the regression analysis using a 10-year data is a big gap (5 times) compared with an 18-year data projection and different countries' data through the same methodology, which is a huge gap of regression coefficient. It means that dumping margin would be very wide range from 7.8% to 38.54% and unstable to calculate. Inflating dumping margin by DOC using regression analysis would not only be inconsistent with WTO rules, but also projection result is unreliable. Originality/value - Literature papers have mainly analyzed WTO law itself. This paper however, would be the first attempt to analyze the DOC's new way of dumping margin calculation in both manners of law and an empirical methodology perspective at the same time.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1053-1065
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• 2018

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (${\geq}3mm$) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

• 대한치과의사협회지
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• 제19권6호통권145호
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• pp.489-490
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• 1981

• 대한치과기공학회지
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• 제2권1호
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• pp.47-49
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• 1980

• KDI Journal of Economic Policy
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• 제31권2호
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• pp.195-234
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• 2009

본 연구에서는 Hummels and Klenow (2005)의 분석방식을 이용하여 1990년대 이후 우리나라의 대중국 수출에 있어서의 수출의 다양도 및 집약도의 상대적인 기여도를 고찰하고 있다. 본 연구에서 수출 다양도란 우리나라를 제외한 대중국 전체 수출국의 수출품목 대비 우리나라의 대중국 수출품목의 비중을 의미한다. 한편, 수출 집약도는 우리나라의 대중국 수출품목 기준으로 우리나라를 제외한 대중국 전체 수출국 대비 우리나라 수출의 비중으로 정의한다. 분석 결과에 의하면, 최근 1990년대 이후 우리나라의 대중국 수출 확대의 주요인은 수출 집약도의 증가였던 것으로 나타난다. 이러한 결과는 중장기적인 수출 호조세의 지속을 위해서는 수출 다양도보다는 수출 집약도가 더 중요한 요인이라는 $Besede{\check{s}}$ and Prusa(2007), Helpman, Melitz, and Rubinstein(2007) 등의 분석과 일치된 결과이다. 수출 다양도의 경우, 무역자유화 초기에 해당되는 1990년대 초반에는 빠르게 증가하나 이후에는 부품 및 자본재 등 일부 품목을 제외하고는 오히려 다소 하락하는 추세를 나타냈다. 한편, 부품과 자본재가 전반적으로 1차 산품, 소비재 등 여타 상품군들에 비해 수출의 지속성(survival)이 높은 것으로 나타난다. 1차 산품, 소비재 등의 경우 수출 개시 후 4년 이내에 전체의 약 75% 수준의 품목이 수출을 중단하는 것으로 분석된 반면, 부품과 자본재는 기술 수준의 구분 없이 1992~2007년 기간 중 지속적으로 수출이 이루어진 품목의 비중이 15% 수준에 이른다. 이러한 분석 결과는 국제분업구조의 진전이 수출의 지속성에 지대한 영향을 미칠 수 있음을 시사한다.

• 대한치과기공학회지
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• 제5권1호
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• pp.13-17
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• 1983

The experimental investication wax performed to study fitness of casting crowns with various investment widely used in Korea. 36 wax patterns were invested and casted according to the regular casting method. The result were as follow : 1. Casting with cristobalite investments of Shofu were seen apart, 0.04mm the tightest space in the linguo and bucco-cervical margin. And the largest deviation, 0.1mm was shown in the central groove 0.1mm was shown in the central groove area of occlusal surface(Jensen Metal) 2. Casting with cristobalite investments of kerr were seen apart, 0.04mm the tightest space in the linguo and bucco-cervical margin And the largest deviation, 0.09 was shown in the central groove area of occlusal surface(Jensen Metal) 3. Casting with Quartz investments of G-C were seen apart, 0.04mm the tightest space in the linguo-cervical margin, And the largest deviation, 0.1mm was shown in the central groove area of occlusal surface(Jensen Metal) 4. Casting with cristobalite investments of shofu were seen apart, 0.01mm the tightest space in the linguo-cervical margin, And the largest deviation, 0.03mm was shown in the central groove of occusal surface(Bo-sung A type gold alloy) 5. Casting with cristobalite investments of kerr showed the best fintness in linguo-cervical margin. And the largest deviation, 0.02mm was shown in the central groove area of occlusal surface(Bosung A type gold alloy) 6. Casting with Quartz investments of G-C were Seen apart, 0.02mm the tightest space in the linguo-cervical margin, And the largest deviation, 0.04mm was shown in the central groove area of occlusal surface(Bo-sung A type gold alloy) 7. Casting with cristobalite investments of shofu were seen apart, 0.01mm the tightest space in the linguo-cervical margin. And the largest deviation, 0.08mm was shown in the buccal cusp area of occlusal surface(Bo-sung B type gold alloy) 8. Casting with cristobalite investments of kerr shown the best fitness in linguo-cervical margin. And the largest deviation, 0.04mm was shown in the central groove atea of occlusal surface(Bosung B type gold alloy) 9. Casting with Quartz investments of G-C were seen apart, 0.03mm the tightest space in the linguo-cervical margin. And the largest deviation, 0.04mm was shown in the central groove area of occlusal surface(Bo-sung B type gold alloy) 10. Casting with cristobalite investments of kerr shown the best fitness and Bo-sung A type gold alloy showed the best fitness.

• 지구물리
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• 제9권4호
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• pp.443-453
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• 2006

남극반도 북부 남셰틀랜드군도 남서부에 위치한 스미스섬 부근 대륙주변부에서 작성된 탄성파 단면도를 분석하여 이 지역의 퇴적층의 분포, 퇴적작용, 대륙붕 형성과정 및 지체구조 발달사를 고찰하였다. 연구지역은 히어로 파쇄대의 대륙쪽 연장선에 위치한 스미스섬을 경계로 지체구조적으로 매우 상이한 두 지역으로 나눌 수 있다. 스미스섬의 남서쪽 지역은 확장중심-해구이 충돌 결과로 형성된 비활동성 대륙주변부가 전개되며, 북동쪽 지역은확장중심과 해구의 구조가 해양에 남아 있는 활동성 대륙주변부가 발달해 있다. 전체적으로 스미스섬을 경계로 북동쪽 지역에서는 두꺼운 퇴적층을 가진 대륙붕 퇴적층지역과 전호분지가 발달되어 있으며, 상대적으로 넓은 대륙사면과 뚜렷한 형태의 해구를 볼 수 있다. 남서쪽 지역은 가파르고 좁은 대륙사면과 국부적으로 형성된 대륙붕분지들이 특징적으로 나타난다. 또한 남서쪽 지역에는 이미 섭입된 확장중심의 열적효과(thermal effect)의 결과로 형성된 것으로 해석되는 기반암 상승부가 대륙붕의 중간부에 잘 발달되어 있다. 기반암 상승부는 스미스섬의 북동쪽을 연장되어 히어로파쇄대를 따라 형성된 경계부가 뚜렷한 지체구조 경계를 형성하지는 않는 것으로 해석된다.