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Digital Watermarking on Image for View-point Change and Malicious Attacks (영상의 시점변화와 악의적 공격에 대한 디지털 워터마킹)

  • Kim, Bo-Ra;Seo, Young-Ho;Kim, Dong-Wook
    • Journal of Broadcast Engineering
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    • v.19 no.3
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    • pp.342-354
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    • 2014
  • This paper deals with digital watermarking methods to protect ownership of image with targeting the ultra-high multi-view or free-view image service in which an arbitrary viewpoint image should be rendered at the user side. The main purpose of it is not to propose a superior method to the previous methods but to show how difficult to construct a watermarking scheme to overcome the viewpoint translation attack. Therefore we target the images with various attacks including viewpoint translation. This paper first shows how high the error rate of the extracted watermark data from viewpoint-translated image by basic schemes of the method using 2DDCT(2D discrete cosine transform) and the one using 2DDWT(2D discrete wavelet transform), which are for 2D image. Because the difficulty in watermarking for the viewpoint-translated image comes from the fact that we don't know the translated viewpoint, we propose a scheme to find the translated viewpoint, which uses the image and the corresponding depth information at the original viewpoint. This method is used to construct the two non-blind watermarking methods to be proposed. They are used to show that recovery of the viewpoint affect a great deal of the error rate of the extracted watermark. Also by comparing the performances of the proposed methods and the previous ones, we show that the proposed ones are better in invisibility and robustness, even if they are non-blind.

Search of Characteristic for Dose Distribution Presented by Multi­isocentric Stereotactic Radiosurgical Plan Using Linear Accelerator (선형 가속기를 이용한 정위적 방사선 수술시 병소내 선량분포의 특성조사)

  • 최경식;오승종;이형구;최보영;전흥재;서태석
    • Progress in Medical Physics
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    • v.14 no.4
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    • pp.225-233
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    • 2003
  • The goal of a radiation treatment plan is to deliver a homogeneous dose to a target with minimal irradiation of the adjacent normal tissues. Dose uniformity is especially important for stereotactic radiosurgery using a linear accelerator. The dose uniformity and high dose delivery of a single spherical dose distribution exceed 70%. This also results with a similar stereotactic radiosurgical plan using a Gamma Knife. The dose distribution produced in a stereotactic radiosurgical plan using a Gamma Knife and Linear accelerator is spherical, and the application of the sphere packing arrangement in a real radiosurgical plan requires much time and skill. In this study, we found a characteristic of dose distribution with transformation of beam parameters that must be considered in a radiosurgical plan for effective radiosurgery. First, we assumed a cylinder type tumor model and a cube type tumor model. Secondly, the results of the tumor models were compared and analyzed with dose profiles and DVH_(Dose Volume Histogram) representative dose distribution. We found the optimal composition of beam parameters_(i.e. collimator size, number of isocenter, gap of isocenters etc.), which allowed the tumor models to be involved in the isodose curve at a high level. In conclusion, the characteristics found in this study are helpful for improving the effectiveness and speed of a radiosurgical plan for stereotactic radiosurgery.

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Implications to High-tech Starts-up Driven from Implementing Business Model of Leading High Tech Ventures : A Case Study of KOSDAQ Listed High-tech Ventures (선도 기술벤처기업의 비즈니스모델 실행이 창업기업에 주는 시사점 : 코스닥상장기업의 사례분석 중심으로)

  • Kim, Jongsun;Yang, Youngseok
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.2
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    • pp.23-33
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    • 2014
  • This paper aims at delivering significant implications to high-tech startups by visualizing the implementation process of leading KOSDAQ listed companies's business model. This paper founded two meaningful outcomes; first, hish-tech starts-up make a clear direction of implementing intangible business model in real business, second, targeting the role model of benchmarking business model among leading companies, by linking common feature between high-tech starts-up and leading KOSDAQ listed venutures sharing one of Key performance indexes falls on viable business model. The research results of visualizing the implementation of leading KOSDAQ listed ventures' business model shows three major implications. First, business model indicates not just simple logic of creating and delivering values, but more shows CEO leading management vehicle. Second, business model represents the multi-dimension process itself of integrating in and out company's core assets and competencies initiated by CEO. Third, financial outcomes of business model is automatic result of implementing on setting target customer, creating value, and delivering it rather than planned strategically. Fourth, the focal points of implementing business model falls on collecting real information from business sites.

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Soft Plasma Flash X-ray Generator Utilizing a Vacuum Discharge Capillary

  • Sato, Eiichi;Hayasi, Yasuomi;Usuki, Tatsumi;Sato, Koetsu;Takayama, Kazuyoshi;Ido, Hideaki
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.400-403
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    • 2002
  • The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.

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The Second Annealing Effect on Giant Magnetoresistance Properties of PtMn Based Spin Valve (이차 열처리가 PtMn계 스핀밸브의 거대자기저항 특성에 미치는 영향)

  • 김광윤;김민정;김희중
    • Journal of the Korean Magnetics Society
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    • v.11 no.2
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    • pp.72-77
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    • 2001
  • Top spin valve films with PtMn antiferromagnetic layers were deposited using a multi-target dc magnetron sputtering in (100)Si substrates overcoated with 500 $\AA$ of Al$_2$O$_3$. Firstly, the post-deposition annealing was performed at 270$\^{C}$ in a unidirectional magnetic field of 3 kOe to induce the crystallographic transformation of the PtMn layer from a fcc (111) to a fct (111) structure. Secondly, the spin valve films were annealed without magnetic fields and magnetic properties were measured. In Si/A1$_2$O$_3$ (500$\AA$)/Ta(50$\AA$)NiFe(40$\AA$)/CoFe(17$\AA$)/Cu(28$\AA$)/CoFe (30$\AA$)PtMn(200$\AA$)Ta(50$\AA$) top spin valve samples, the MR ratio decreased slowly with increasing annealing temperature up to 325$\^{C}$. But above 325$\^{C}$, the MR ratio decreased rapidly to 1%, due to a collapse of the exchange coupling between a antiferromagnetic layer and a pinned layer with increasing annealing temperature. Also above 325$\^{C}$, the exchange biased field rapidly decreased and the interlayer coupling field rapidly increased with increasing annealing temperature. A change in the interlayer coupling field was resulted from the increase in interface roughness due to Mn-interdiffusion through the grain boundaries. We confirmed the temperature in changing magnetic properties agreed well with the blocking temperature of PtMn based spin valve structure.

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The Management Methods of Multi-Purpose Ecological Reservoir by System Thinking - Focused on Anteo Eco Park - (시스템 사고를 통한 다기능 생태저류지의 관리방안 - 광명 안터생태공원을 중심으로 -)

  • Lee, HyunJi;You, Soojin;Chon, Jinhyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.2
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    • pp.1-17
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    • 2015
  • Ecological reservoir is a multifunctional space where provides the functions of retention, animal habitat and improvement of ecosystem health and landscape. The ecological reservoir of Anteo Eco Park located in Gwangmyeong-si has established to functions for water purification, maintenance of healthy aquatic ecosystem. Because the Anteo Eco Park is located in the site where nonpoint pollutant materials flow in, Anteo Eco Park has potential factors which aquatic ecosystem health deteriorates and damages the habitat of golden frog(Rana plancyi chosenica) which is restoration target species. Therefore, the purpose of this study is to suggest the plan to manage the variables which impede the right functions of aquatic ecosystem by understanding the causal loop diagram for the change of water quality environment and the interaction of predator-prey through system thinking. The results are as follows. First, the study showed that the individual number of golden frog which is an indicator species of Anteo Eco Park is threatened by snakeheaded fish, which is an upper predator. Therefore, balanced food chain should be hold to protect golden frog by capturing the snakeheaded fish which is individual number's density is high, and the monitoring management of the individual number for predator(snakeheaded fish)-prey(golden frog) should be performed. Second, the study represented that water pollution and carnification is caused by the sediment as the dead body of the large emergent vegetation in the winter cumulates as sediment. Ecological reservoir in Anteo Eco Park has been managed by eliminating the dead body of the large emergent vegetation, but the guideline for the proper density maintenance of vegetation community is additionally needed. Lastly, the study showed that aquatic ecosystem of Anteo Eco Park where is contaminated from the inflow of nonpoint pollutants affects the individual number's decline of golden frog and snakeheaded fish. Accordingly, the creation of a buffer area and a substitution wetland is needed in the periphery of the Anteo Eco Park to control the inflow of nonpoint pollutants including organic matters, nutrients and heavy metals. This study will be helpful that Anteo Eco Park improves the regional landscape and maintain healthy aquatic ecosystem space for the park visitors including local residents.

Human Papillomavirus Vaccine Awareness, Acceptability, and Decision-Making Factors among Chinese College Students

  • Wang, Shao-Ming;Zhang, Shao-Kai;Pan, Xiong-Fei;Ren, Ze-Fang;Yang, Chun-Xia;Wang, Zeng-Zhen;Gao, Xiao-Hong;Li, Man;Zheng, Quan-Qing;Ma, Wei;Zhao, Fang-Hui;Qiao, You-Lin;Sivasubramaniam, Priya
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3239-3245
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    • 2014
  • Background: College students are recommended as the target groups for catch-up human papillomavirus (HPV) vaccination. Systematical exploration of awareness, acceptability, and decision-making factors of HPV vaccination among Chinese college students has been limited. Materials and Methods: A multi-center survey was conducted in mainland China between November 2011 and May 2012. College students aged 18-22 years were stratified by their grade, gender, and major for sampling. Socio-demographic and HPV-related information such as knowledge, perceptions, acceptability, and attitudes were collected through a questionnaire. Results: A total of 3,497 undergraduates completed the questionnaire, among which 1,686 were males. The acceptability of the HPV vaccine was high (70.8%). Undergraduates from high-level universities, at lower grade, or with greater prior knowledge of HPV vaccines showed higher acceptability of HPV vaccination ($p_{trend}$ <0.001). Additionally, undergraduates with vaccination experience outside the National Expanded Program on Immunization (OR=1.29; 95%CI: 1.10-1.51) or fear of HPV-related diseases (OR=2.79; 95%CI: 2.28-3.41) were more willing to accept HPV vaccination. General knowledge of HPV vaccine was low among undergraduates, and safety was a major concern (71.05%). The majority of students wished to pay less than 300RMB for HPV vaccine and chose the Chinese Center for Disease Control and Prevention as the most appropriate venue for vaccination. Conclusions: Although most undergraduates demonstrate positive attitudes towards HPV vaccination, challenges pertaining to introduction exist in China. Corresponding proactive education and governmental subsidy to do so are urgently needed by this age-group population. Suggestions and potential strategies indicated may help shape the future HPV vaccination program in China.

Run-time Memory Optimization Algorithm for the DDMB Architecture (DDMB 구조에서의 런타임 메모리 최적화 알고리즘)

  • Cho, Jeong-Hun;Paek, Yun-Heung;Kwon, Soo-Hyun
    • The KIPS Transactions:PartA
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    • v.13A no.5 s.102
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    • pp.413-420
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    • 2006
  • Most vendors of digital signal processors (DSPs) support a Harvard architecture, which has two or more memory buses, one for program and one or more for data and allow the processor to access multiple words of data from memory in a single instruction cycle. We already addressed how to efficiently assign data to multi-memory banks in our previous work. This paper reports on our recent attempt to optimize run-time memory. The run-time environment for dual data memory banks (DBMBs) requires two run-time stacks to control activation records located in two memory banks corresponding to calling procedures. However, activation records of two memory banks for a procedure are able to have different size. As a consequence, dual run-time stacks can be unbalanced whenever a procedure is called. This unbalance between two memory banks causes that usage of one memory bank can exceed the extent of on-chip memory area although there is free area in the other memory bank. We attempt balancing dual run-time slacks to enhance efficiently utilization of on-chip memory in this paper. The experimental results have revealed that although our algorithm is relatively quite simple, it still can utilize run-time memories efficiently; thus enabling our compiler to run extremely fast, yet minimizing the usage of un-time memory in the target code.

Determinants of International Standardization: An Empirical Analysis in the ICT field (ICT 국제표준화 결정요인에 관한 실증분석 연구)

  • Kim, Bum-Hoan;Park, Jongbong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.11
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    • pp.1064-1076
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    • 2012
  • This study is an attempt to identify factors determining the success of international standardization and understand the relationship between the factors, such as government-driven standardization activities. Six factors were identified through factor analysis; namely, 'Direct government support', 'Indirect government support', 'Utilization of standardization bodies', 'Standardization strategy', 'Attainment of a dominant market power', and 'Adoption as an international standard.' The results showed that firstly, support from the government, whether direct or indirect, had no direct effect on the outcome of international standardization efforts, but produced an indirect influence on it through mediating factors such as the attainment of a dominant market power. Secondly, the attainment of a dominant market power proved to be the most important success factor of international standardization, suggesting that the government must direct its efforts to help boost the market power of target standards through measures like promoting a timely market entry and the development of high-quality standards, in a manner to induce market satisfaction, increasing lock-in effects and building a quasi-vertical integration system. Thirdly, direct support from the government holds the key to the success of international standardization with de jure standardization bodies, while the strategic use of standardization bodies appears the most important for the positive outcome of standardization concerning de facto standardization bodies.

The Effect of Barrel Vibration Intensity to the Plating Thickness Distribution

  • Lee, Jun-Ho;Roselle D. Llido
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 1999.10a
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    • pp.15-15
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    • 1999
  • In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.

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