• Title/Summary/Keyword: Rebuild

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Comparison of Experimental and Radiation Therapy Planning (RTP) Dose Distributions on Air Cavity (공동(air cavity)의 존재 시 실험적 선량분포와 치료계획상의 선량분포 비교)

  • Kim, Yon-Lae;Suh, Tae-Suk;Ko, Shin-Gwan;Lee, Jeong-Woo
    • Journal of radiological science and technology
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    • v.33 no.3
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    • pp.261-268
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    • 2010
  • This study is compared that the dose distribution by experimentation and radiation therapy planning (RTP) when the air cavity region was treated high energy photon. The dose measurements were performed with a 6 MV photon beam of linear accelerator. The polystyrene and self made acyl phantom were similar to tissue density of the human body. A parallel plate chamber was connected to an electrometer. The measurement setup was SCD (Source Chamber Distance) 100 cm and the distance of surface from air cavity was 3 cm. Absorbed dose of interface were measured by area and height. The percent depth dose were measured presence and absence of air cavity, depth according to a ratio of field size and air cavity size. The dose distribution on planning was expressed to do the inhomogeneity correction. As the area of air cavity was increased, the absorbed dose were gradually reduced. It was slightly increased, when the height of air cavity was changed from 0 cm to 0.5 cm. After the point, dose was decreased. In case of presence of air cavity, dose after distal air cavity interface was more great than absence of air cavity. The rebuild up by field size and area of air cavity occurred for field size, $4{\times}4\;cm^2$, $5{\times}5\;cm^2$ and $6{\times}6\;cm^2$, with fixed on area of air cavity, $5{\times}5\;cm^2$. But it didn't occur at $10{\times}10\;cm^2$ field size. On the contrary, the field size was fixed on $5{\times}5\;cm^2$, rebuild up occurred in area of air cavity, $4{\times}4\;cm^2$, $5{\times}5\;cm^2$. but, it did not occur for air cavity, $2{\times}2\;cm^2$, $3{\times}3\;cm^2$. All of the radiation therapy planning were not occurred rebuild up. It was required to pay attention to treat tumor in air cavity because the dose distribution of planning was different from the dose distribution of patient.

USN's Efforts to Rebuild its Combat Power in an Era of Great Power Competition (강대국 간의 경쟁시대와 미 해군의 증강 노력)

  • Jung, Ho-Sub
    • Strategy21
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    • s.44
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    • pp.5-27
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    • 2018
  • The purpose of this paper is to look at USN's efforts to rebuild its combat power in the face of a reemergence of great powers competition, and to propose some recommendations for the ROKN. In addition to the plan to augment its fleet towards a 355-ships capacity, the USN is pursuing to improve exponentially combat lethality(quality) of its existing fleet by means of innovative science and technology. In other words, the USN is putting its utmost efforts to improve readiness of current forces, to modernize maintenance facilities such as naval shipyards, and simultaneously to invest in innovative weapons system R&D for the future. After all, the USN seems to pursue innovations in advanced military Science & Technology as the best way to ensure continued supremacy in the coming strategic competition between great powers. However, it is to be seen whether the USN can smoothly continue these efforts to rebuild combat strength vis-a-vis its new competition peers, namely China and Russian navy, due to the stringent fiscal constraints, originating, among others, from the 2011 Budget Control Act effective yet. Then, it seems to be China's unilateral and assertive behaviors to expand its maritime jurisdiction in the South China Sea that drives the USN's rebuild-up efforts of the future. Now, some changes began to be perceived in the basic framework of the hitherto regional maritime security, in the name of declining sea control of the USN as well as withering maritime order based on international law and norms. However, the ROK-US alliance system is the most excellent security mechanism upon which the ROK, as a trading power, depends for its survival and prosperity. In addition, as denuclearization of North Korea seems to take significant time and efforts to accomplish in the years to come, nuclear umbrella and extended deterrence by the US is still noting but indispensible for the security of the ROK. In this connection, the naval cooperation between ROKN and USN should be seen and strengthened as the most important deterrents to North Korean nuclear and missile threats, as well as to potential maritime provocation by neighboring countries. Based on these observations, this paper argues that the ROK Navy should try to expand its own deterrent capability by pursuing selective technological innovation in order to prevent this country's destiny from being dictated by other powers. In doing so, however, it may be too risky for the ROK to pursue the emerging, disruptive innovative technologies such as rail gun, hypersonic weapon... etc., due to enormous budget, time, and very thin chance of success. This paper recommends, therefore, to carefully select and extensively invest on the most cost-effective technological innovations, suitable in the operational environments of the ROK. In particular, this paper stresses the following six areas as most potential naval innovations for the ROK Navy: long range precision strike; air and missile defense at sea; ASW with various unmanned maritime system (UMS) such as USV, UUV based on advanced hydraulic acoustic sensor (Sonar) technology; network; digitalization for the use of AI and big data; and nuclear-powered attack submarines as a strategic deterrent.

보철 수복시 치간 유두에 대한 고려 사항

  • Lee, Sung-Bok;Lee, Seung-Gyu
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.10 no.1
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    • pp.30-45
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    • 2001
  • In recent years, clinicians' and dentists' esthetic demands in dentistry have increased rapidly. The ultimate goal in modern restorative dentistry is to achieve "white" and "pink" esthetics in the esthetically important zones. Therefore, modern esthetic dentistry involves not only the restoration of lost teeth and their associated hard tissues, but increasingly the management and reconstruction of the encasing gingiva with adequate surgical techniques. Interdental space are filled by interdental papilla in the healthy gingiva, preventing plaque deposition and protecting periodontal tissue from infection. This also inhibits impaction of food remnants and whistling through the teeth during speech. These functional aspects are obviously important, but esthetic aspects are important as well. Complete and predictable restoration of lost interdental papillae remains one of the biggest challenges in periodontal reconstructive surgery. One of the most challenging and least predictable problems is the reconstruction of the lost interdental papilla. The interdental papilla, as a structure with minor blood supply, was left more or less untouched by clinicians. Most of the reconstructive techniques to rebuild lost interdental papillae focus on the maxillary anterior region, where esthetic defects appear interproximally as "black triangle". Causes for interdental tissue loss are, for example, commom periodontal diseases, tooth extraction, excessive surgical periodontal treatment, and localized progressive gingiva and periodontal diseases. If an interdental papilla is absent because of a diastema, orthodontic closure is the treatment of choice. "Creeping" papilla formation has been described by closing the interdental space and creating a contact area. In certain cases this formation can also be achieved with appropriate restorative techniques and alteration of the mesial contours of the adjacent teeth. The presence of an interdental papilla depends on the distance between the crest of bone and the interproximal contact point, allowing it to fill interdental spaces with soft tissue by altering the mesial contours of the adjacent teeth and positioning the contact point more apically. The interdental tissue can also be conditioned with the use of provisional crowns prior to the definitive restoration. If all other procedures are contraindicated or fail, prosthetic solutions have to be considered as the last possibility to rebuild lost interdental papillae. Interdental spaces can be filled using pink-colored resin or porcelain, and the use of a removable gingival mask might be the last opportunity to hide severe tissue defects.

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An improvement method of weapon system software standards material quality using virtualization technology (가상화 기술을 활용한 무기체계 소프트웨어 규격자료 품질향상 방안 연구)

  • Choi, Minkwan;Kook, Seunghak;Lee, Taeho
    • Journal of Software Engineering Society
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    • v.29 no.1
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    • pp.1-6
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    • 2020
  • Recently, software has taken up an increasing share of the weapons system. The software development environment is also becoming very diverse. In the field of weapons software, software technical documents, source codes, and execution files are standardized as defense standards material. Through defense standards, the software file lists and development environments for creating software execution files are required to be documented. However, additional efforts to rebuild the software development environment are needed to recreate the software execution file based on defense standards material after the end of R&D. Therefore, in this study, we propose an improvement method for the quality of software standards material using virtualization technology. This is expected to reduce efforts to rebuild the software development environment and solve problems caused by discontinuation of the development environment.

Dose Alterations at the Distal Surface by Tissue Inhomogeneity in High Energy Photon Beam (조직 불균질성에 의한 고에너지 광자선의 선량변화)

  • Kim, Young-Ai;Choi, Tae-Jin;Kim, Ok-Bae
    • Radiation Oncology Journal
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    • v.13 no.3
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    • pp.277-283
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    • 1995
  • Purpose : This study was performed to measure dose alteration at the air-tissue interface resulting from rebuild-up to the loss of charged particle equilibrium in the tissues around the air-tissue interfaces. Materials and Methods : The 6 and 10-MV photon beam in dual energy linear accelerator were used to measure the surface dose at the air-tissue interface The polystyrene phantom sized $25{\times}25{\times}5\;cm^3$ and a water phantom sized $29{\times}29{\times}48\;cm^3$ which incorporates a parallel-plate ionization chamber in the distal side of air gap were used in this study. The treatment field sizes were $5{\times}5\;cm^2,\;10{\times}10\;cm^2\;and\;20{\times}20\;cm^2$. Air cavity thickness was variable from 10 mm to 50 mm. The observed-expected ratio (OER) was defined as the ratio of dose measured at the distal junction that is air-tissue interface to the dose measured at the same point in a homogeneous phantom. Results : In this experiment, the result of OER was close or slightly over than 1.0 for the large field size but much less (about 0.565) than 1.0 for the small field size in both photon energy. The factors to affect the dose distribution at the air-tissue interface were the field size, the thickness of air cavity. and the photon energy. Conclusion : Thus, the radiation oncologist should take into account dose reduction at the air-tissue interface when planning the head and neck cancer especially pharynx and laryngeal lesions, because the dose can be less nearly $29{\%}$ than predicted value.

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A Study on Evaluation Indicator of School Building (학교 건축물 평가지표 개발 연구)

  • Yoo, Taek-Dong;Cho, Jin-Il;Kim, Sung-Jung;Cho, Kyung-Suk
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.5 no.2
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    • pp.31-52
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    • 2006
  • It presented the specialty and efficient evaluation indicator and a method which corresponds in each quality classified with 4 fields - an use and the function, the environment and an equipment, the structure stability, an main finishing material from plan side against an existing school facility in order to suit in development of the standard indicator which has become fixed quantity and demand of evaluation method for an analysis of the object school facilities to rebuild. So it presented the method which is the fixed quantity evaluation from economic viewpoint as possible for evaluating the maintenance cost by the expenses involved and durable years increase in rebuilding of objective school facility.

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Empirical Study on Digital Core-Banking System

  • Kang, Hee Yong;Weon, Dal Soo
    • International Journal of Internet, Broadcasting and Communication
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    • v.9 no.2
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    • pp.48-57
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    • 2017
  • In the last few years, banks have experienced more challenging market than any other times. They need to find new ways to reconnect with their customers and rebuild their trust. But in the race to the future some banks are taking clear lead. Research works show that while high perform leading banks are different, they also share some common characteristics and principles that have allowed them to move ahead to profitable growth. Cost cutting is no longer enough to succeed in tomorrow's world. Instead, the IT function needs to work shoulder-to-shoulder with the business to support the growth agenda. Therefore "C" level's attention is moving from cost reduction towards customer experience, speeding to market for new offerings, analytics and distribution channel enhancements, taking advantage of several levers that will shape the technology agenda for the high performing organization. Next generation of digital core-banking solutions will improve pre-existing capabilities, introduce new innovations and drive qualities such as flexibility and scalability to support time to market.

Paper Machine Rebuilds and Solutions for Process Improvement (초지기 개조 및 공정개선 방안)

  • Ollikainen, Mika
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2007.05a
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    • pp.57-82
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    • 2007
  • Rebuilding an existing paper machine is often a very profitable way for papermakers to increase the cash flow created by an older paper machine. In Metso Paper we have placed particular emphasis in recent years on developing concepts and products specifically for rebuild needs. The outcome of this work can now be seen as a wide selection of products offering quite possibly the best coverage of all time of specific improvement targets. Different needs can be addressed through truly different solutions. Selecting the best-fit alternatives will offer great upgrade options for all paper machines and paper grades. Metso Paper's long experience with high-speed paper machines has been put to good use to create more cost-effective small and mid-sized solutions with the reliability and quality of bigger and faster paper machines. This paper has discussed some of the most interesting and latest configurations available today for paper machine rebuilds.

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