• Title/Summary/Keyword: Margins

Search Result 1,077, Processing Time 0.025 seconds

Late Quaternary Depositional Processes in the Korea Plateau and Ulleung Interplain Gap, East Sea (동해 한국대지 및 울릉 분지간통로의 제4기 후기 해저퇴적작용)

  • 윤석훈;박장준;한상준
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.8 no.2
    • /
    • pp.187-198
    • /
    • 2003
  • High-resolution (Chirp, 3-11 kHz) echo facies and sedimentary facies of piston-core sediments were analyzed to reveal the late Quaternary depositional processes in the Korea Plateau and Ulleung Interplain Gap. The Korea Plateau is an Isolated topographic high with a very restricted input of terrigenous sediments, and its slope is characterized by a thin sediment cover and various-scale submarine canyons and valleys. Echo and sedimentary facies suggest that the plateau has been moulded mainly by persistent (hemi) pelagic sedimentation and intermittent settling of volcanic ashes. Sediments on the plateau slope and steep margins of ridges and seamounts were reworked by earthquake-induced, large-scale slope failures accompanied by slides, slumps and debris flows. As major fraction of the reworked sediments consists of (hemi) pelagic clay particles, large amounts of sediments released from mass flows were easily suspended to form turbid nepheloid layers rather than bottom-hugging turbidity currents, which flowed further downslope through the submarine canyons and spreaded over the Ulleung Basin plain. In the Ulleung Interplain Gap, sediments were introduced mainly by (hemi) pelagic settling and subordinate episodic mass flows (turbidity currents and debris flows) along the submarine channels from the slopes of the Oki Bank and Dok Island. The sediments in the Ulleung Interplain Channel and its margin were actively eroded and reworked by the deep water flow from the Japan Basin.

SURFACE ROUGHNESS AND MICROLEAKAGE OF CLASS V COMPOSITE RESTORATIONS : EFFECT OF SURFACE SEALING (치경부 5급 와동 수복물의 표면 거칠기와 미세누출에 관한 연구 : 표면 전색의 효과)

  • Kim, Min-Jeong;Lee, Mi-Jeong;Yu, Mi-Kyung;Park, Soo-Joung;Lee, Kwang-Won
    • Restorative Dentistry and Endodontics
    • /
    • v.30 no.1
    • /
    • pp.22-30
    • /
    • 2005
  • The purpose of this study was to compare the effect of surface sealing materials on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 after applying Single Bond. Following 7 days storage in distilled water at $37^{\circ}C$, the restorations were sealed as following systems : No sealing ; Single Bond Adhesive ; Biscover ; Fortify ; Optiguard. Then, toothbrush abrasion test was conducted using a wear testing machine. Surface roughness was measured by means of profilometer before and after toothbrushing and the results were statistically analysed by using a paired t-test and ANOVA. The bonded interfaces and the changes of surface roughness were examined by SEM. For microleakage test, specimens were stained in a $2\%$ methylene blue solution, then longitudinally sectioned and analyzed for leakage at occlusal and cervical interfaces using stereomicroscope. The results were statistically analysed by using a Kruskal-Wallis and Mann-Whitney U test. Surface roughness was increasing in all groups after toothbrushing, but no statistically significant differences. In SEM observation, surface sealant was partially retained and partially detached in bonded interfaces. Especially, microgap was identified in cervical margins. In microleakage test, there was better seal in the enamel region and a significant difference between groups at occlusal margin. Control group and Single Bond group had significantly better marginal seal at enamel margin than cervical margin.

MICROLEAKAGE OF CL V COMPOSITE RESTORATIONS USING VARIOUS LIGHT CURING METHODS (광중합 복합레진 수복시 여러 광조사 방법에 따른 미세변연누출에 관한 연구)

  • Yang, Chol-Young;Yoo, Hyeon-Mee;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
    • /
    • v.25 no.2
    • /
    • pp.299-308
    • /
    • 2000
  • The purpose of this in vitro study was to evaluate the microleakage of 5 curing methods in class V composite restorations which are composed of two-step light curing, pulse-delay cure, low curing-light intensity, moderate curing-light intensity and high curing-light intensity. In this study, class V cavities were prepared on buccal and lingual surfaces of 50 extracted human upper or lower molars on cementum margin. Single Bond adhesive and Z-100 shade A2 were applied for each group following the manufacture's instruction. The experimental teeth were randomly divided into 5 groups of 10 samples (20 surfaces) each. Group 1: two-step light curing; Group 2: pulse-delay cure; Group 3: low curing-light intensity; Group 4: moderate curing-light intensity; Group 5: high curing-light intensity. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 60 teeth were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen was then observed with a stereomicroscope at ${\times}20$. The composite resin/tooth interfaces were examined under Scanning Electron Microscopy. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA and Dunn's Method. The results of this study were as follows. 1. In all groups, the leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. No group in this study showed significant differences in leakage values at both the enamel and the dentin margins(P<0.05). 3. In all groups, the gaps seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 4. The gaps in this study showed significant differences and two-step light-curing and low curing-light intensity produced significant less gap than high curing-light intensity(P<0.05).

  • PDF

Lessons from Haitai Distribution Inc's experience in Korea

  • Cho, Young-Sang
    • Journal of Distribution Science
    • /
    • v.9 no.3
    • /
    • pp.25-36
    • /
    • 2011
  • Owing to the rapid growth of hypermarket/discount store formats since 1996, Korean retailing has suddenly attracted the significant attention from researchers. Before the emergence of large scale retailers such as E-Mart, Lotte Mart and Tesco Korea, there were the two retail formats who led the Korean retailing in the modern retailing history: department store and supermarket formats. Nevertheless, there has been little literature concerned about the two retail formats as a case study, while some authors have paid their attention to hypermarket/discount store formats. In addition, when mentioning the development process of retailing history, it is less likely that authors have made an effort to illustrate supermarket retailing history. In order to regard supermarket retailing as part of the Korean retailing, it is interesting to look at a representative supermarket retailer, Haitai, who was one of the subsidiaries of Haitai chaebol. Based on supermarket retailing, the company which was established as a joint venture in 1974 led a supermarket retailing in the Korean modernised retailing history. Before analysing whether Haitai failed or not, the definition of failure should be illustrated. With regard to the term, failure, in the academic world, authors have interchangeably used the following terms: failure, divestment, closure, organisational restructuring, and exit. To collect research data as a case study, the author adopted an in-depth interview method. The research is based on research interviews with 13 ex-staff who left after Haitai went bankruptcy, from store management department to merchandise department. By investigating Haitai's experiences through field interviews, the research found that Haitai restructured organisational decision-making process at the early stage when companies started to modernise organisational charts, benchmarking sophisticated retailing knowledge through the strategic alliance with a Japanese retailer. In respect of buying system, the company established firmly buying functions by adopting central buying system, and further, outstandingly allocated considerable marketing resources to the development of retailer brands with the dedicated team of retailer brand development. In the grocery retailing, abandoning a 'no-frill' packaging concept, the introduction of retailer brand packaging equal to, or better than national brand packaging design, encouraged other retailers to change their retailer brand development strategies. In product sourcing ways, Haitai organised for the first time the overseas sourcing team with the aim of improving the profit margins of foreign products and providing exotic products for customers, followed by other retailers. Regarding distribution system, the company introduced the innovative idea which delivered products ordered by stores directly to each store withboth its own vehicles and its own warehouse in which could deal with dry foods, chilly foods, frozen food, and non-foods, and even, process produce. In addition, Haitai developed many promotional methods to attract more customers like 'the guarantee of the lowest price', and expanded its own business to US in 1996, although withdrew, because of bankruptcy in 1997. Together with POS introduction in 1994, Haitai made a significant contribution to the development of the Korean retailing, influencing other retailers in many aspects. As a case study, the study has provided a number of lessons from Haitai's experiences for academicians and practitioners, suggesting that its history should be involved in the Korean modernised retailing.

  • PDF

Complete denture making in a patient of partial glossectomy using polished surface impression taking and direct metal laser sintering method: A case report (부분 설절제술을 받은 환자에서의 연마면 인상 및 Direct Metal Laser Sintering 을 이용한 총의치 제작 증례)

  • Jung, Yeon-Wook;Lee, Gyeong-Je;Kim, Hee-Jung
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.57 no.4
    • /
    • pp.350-355
    • /
    • 2019
  • For the success of complete denture, three essential requirements such as retention, stability and support are needed. Moreover, due to the absorption of residual ridge and scarring due to the surgery, when making a complete denture, which is difficult to form the mandibular lingual margins, various considerations such as the arrangement of the Non-anatomical dl non-anatomical teeth, the polished surface impression, the internally weighted metal framework and the use of the denture adhesive cream are necessary. In this case report, the patient has a severely resorbed edentulous ridge from severe periodontitis and has some soft tissue problems after the glossectomy due to tongue cancer. To obtain additional retention and stability, some trials such as polished surface impression taking, internally weighted metal insertion and minimal pressure impression were done for the better result. Moreover To make a metal framework that precisely shapes the desired three-dimensional shape and reduces the complicated process, minimal pressure impression method and direct metal laser sintering technique were used.

Tectonic Link between NE China and Korean Peninsula, Revealed by Interpreting CHAMP Satellite Magnetic and GRACE Satellite Gravity Data

  • Choi, Sungchan;Oh, Chang-Whan;Luehr, Herrmann
    • Journal of the Korean Geophysical Society
    • /
    • v.9 no.3
    • /
    • pp.209-217
    • /
    • 2006
  • The major continental blocks in NE-Asia are the North China Block and the South China Blo, which have collided, starting from the Korean peninsula. The suture zone in NE China between two blocks is well defined from the QinIing-Dabie-Orogenic Belt to the Jiaodong (Sulu) Belt by the geological and geophysical interpretation. The discovery of high pressure metamorphic rocks in the Hongsung area of the Korean peninsula can be used to estimate the suture zone. This indicates that the suture zone in the Jiaodong Belt might be extended to Hongsung area. However, due to the lack of geological and geophysical data over the Yellow sea, the extension of the suture zone to the Korean peninsula across the Yellow Sea is obscure. To find out the tectonic relationship between NE China and the Korean peninsula it is necessary to complete U-ie homogeneous geophysical dataset of NE Asia, which can be provided by satellite observations. The CHAMP lithospheric magnetic field (MF3) and CHAMP-GRACE gravity field, combined with surface measured data, allow a much more accurate in-ference of tectonic structures than previously available. The CHAMP magnetic anomaly map reveals significant magnetic lows in the Yellow Sea near Nanjing and Hongsung, where are characterized by gravity highs on U-ie CHAMP-GRACE gravity anomaly map. To evaluate the depth and location of poten-tial field anomaly causative bodies, the Euler Deconvolution method is implemented. After comparing the two potential field solutions with the simplified geological map containing tectonic lines and the distribution of earthquakes epicenters, it is found that the derived structure boundaries of both are well coincident with the seismic activities as well as with the tectonic lineaments. The interpretation of the CHAMP satellite magnetic and GRACE satellite gravity datasets reveal two tectonic boundaries in U-ie Yellow Sea and the Korean peninsula, indicating U-ie norttiern and southern margins of the suture zone between the North China Block and the South China Block. The former is extended from the Jiaodong Belt in East China to the Imjingang Belt on the Korean peninsula, the later from Nanjing, East China, to Hongsung, the Korean peninsula. The tectonic movement in or near the suture zone might be responsible for the seismic activities in the western region of the Korean Peninsula and the development of the Yellow Sea sedimentary basin.

  • PDF

A Study on the Effects of the R&D Activities and Patent on the Corporate Performance of Medical Device Firms in Korea (국내 의료기기 제조기업의 연구개발활동과 특허가 기업 경영성과에 미치는 영향에 관한 연구)

  • Kim, Dosung;Lee, Jungsoo;Cho, Sung Han;Kim, Min Seok;Kim, Nam-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.157-165
    • /
    • 2018
  • Companies conduct R&D for continuous development and enhancement of corporate value, and obtain patents as an intangible asset resulting from this process. This study screened 103 medical device firms whose R&D information, patent information, and management performance information were all published to determine how R&D activities and patents affect corporate operational performance. The number of patents, R&D costs, company type and Inno-Biz of the company were set as independent variables, and the companies' sales, intangible assets, operating profit ratios, net profit margins, corporate ratings and profit-related financial ratios were used as dependent variables. The results confirmed that R&D expenditure had negative (-) effects on most indicators, including sales volume, operating profit ratio, and net profit ratio, while it had positive (+) [ED highlight - these are unnecessary if negative and positive are also written out.] effects only on intangible assets. Additionally, domestic patents were found to have negative (-) effects on sales, cash flow ratings, and dropped capital return, and positive (+) effects on net profit growth. Moreover, the business performance variables affected by the company characteristics were sales volume and cash flow ratings. The medical device industry is dominated by small and medium-sized businesses Although research and development activities and patents have been shown to have a negative impact on corporate management in the short term, they are expected to have a positive long-term impact when reflecting the characteristics of the medical device industry that must undergo clinical trials and authorization procedures after R&D.

Application of the ExacTrac System in Respiratory Gated Radiotherapy for Lung Cancer Patients (폐암 환자의 호흡연동방사선치료를 위한 ExacTrac 시스템 적용)

  • Ko, Seung Young;Lee, Jung Il
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.3
    • /
    • pp.325-332
    • /
    • 2019
  • This study analyzed the movement of tumors using 4DCT. Appropriate uniform IM were identified using TC, II and CI depending on ITV margins. DVH and NTCP were also compared in each case. Dose analysis on tumors with uniform IM showed that the optimal treatment plan for satisfying all TC, CI, II was evaluated as 2 mm in phase 20 and 3 mm in 40%. That was compared to the dose from the normal tissues of $PTV_{20}$, $PTV_{40}$. In the 20% radiation field, V5, V10, and V20 for the lungs increased 1.49, 1.26, and 0.65%, while 40% increased by 1.9, 2.41 and 1.23%. NTCP had a dose increase of 0.57 to 0.029% from 20% and 40%. There was a dose increase in the spinal cord and heart at uniform IM, but there was no significant difference. These data suggest that the ITV setting of 20%, phase for Respiratory Gated Radiotherapy using Novalis ExacTrac system can be applied with a uniform IM 2 mm and 40% with 3 mm for optimal treatment plan.

A Renal Size Discrepancy among the Findings of Renal Sonogram in Children with Their First Episode of Pyelonephritis is One of the Useful Parameters to Predict the Presence of Cortical Defects on the Acute DMSA Renal Scan

  • Kwon, Yoowon;Jin, Bo kyeong;Rhie, Seonkyeong;Lee, Jun Ho
    • Childhood Kidney Diseases
    • /
    • v.23 no.1
    • /
    • pp.36-42
    • /
    • 2019
  • Purpose: We investigated whether a renal size discrepancy on a renal sonogram (US) in children with febrile urinary tract infection (UTI) was correlated with the presence of cortical defects on their dimercaptosuccinic acid (DMSA) renal scan. Methods: We examined 911 children who were admitted consecutively to our hospital with their first episode of febrile UTI from March 2001 to September 2014. All enrolled children underwent a US and DMSA scan during admission. According to the US findings, including the renal size discrepancy, data were compared between children with positive and negative DMSA scan results. A positive DMSA scan result was defined as reduced or absent tracer localization and indistinct margins that did not deform the renal contour. Results: Mean renal lengths of the right and left kidneys were larger in children with positive DMSA scan results than in children with negative DMSA scan results ($63.2{\pm}11.3mm$ vs. $58.4{\pm}7.8mm$, P<0.001; $64.9{\pm}11.2mm$ vs. $59.9{\pm}7.9mm$, P<0.001; respectively). A significant difference was observed in both renal lengths between children with positive and negative DMSA scan results ($4.6{\pm}3.8mm$ vs. $3.3{\pm}2.6mm$, P<0.001). A multiple logistic regression analysis, revealed that a small kidney, cortical thinning, and a renal length discrepancy on US findings were significant factors for predicting the presence of cortical defects on an acute DMSA scan [P=0.028, 95% confidence interval (CI) 1.054-2.547; P= 0.004, 95% CI 1.354- 4.810; P<0.001, 95% CI 1.077-1.190, respectively]. Conclusion: In conclusion, a renal size discrepancy on US findings in children with their first episode of febrile UTI was a helpful tool for predicting the presence of cortical defects on an acute DMSA scan.

A Study on the Quality of a Frozen Section of Breast Resection Margin during Breast-Conserving Surgery (유방 보존술 중 절제면 동결절편검사의 질 향상에 관한 연구)

  • Choi, Byung-Il;Chin, Su-Sie
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.53 no.3
    • /
    • pp.233-240
    • /
    • 2021
  • Evaluation of the resected margins of the frozen section during breast-conserving surgery can determine the presence of cancer cells in a short time and have a significant impact on the scope of surgery and the prognosis of the patient. However, breast tissue is composed of adipose tissue, which affects the accuracy of the test. In this study, a new method was applied to the resected surface of the frozen section in which wiping the surface of the frozen section block with alcohol was expected to expose the parenchyma to the surface as the adipose tissue would melt momentarily. Indeed, of the total of 98 cases, 37 cases showed a better exposure ratio of the parenchyma in the improved frozen section test than in the previous frozen section test. Of the 37 cases with increased visibility of parenchymal sections obtained by this method, two cases of ductal carcinoma in situ (DCIS) were detected. Although there are limitations such as turnaround time (TAT), the diagnostic accuracy of histopathologic examination of the frozen section may improve through this method and may have a direct impact on patient safety, and should therefore be researched further.