• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.815-817
• /
• 2022

포인트 클라우드는 다수의 포인트로 구성된 3차원 미디어 콘텐츠로, 기존의 2차원 미디어에 비해 방대한 크기를 가진다. 이러한 포인트 클라우드 데이터를 효과적으로 소비하기 위해서는 포인트 클라우드 데이터를 압축하는 것이 필수적으로 요구된다. 이에 따라, 국제 표준화 기구 The Moving Picture Experts Group (MPEG)에서는 2차원 비디오 코덱 기반의 포인트 클라우드 압축 방안인 V-PCC 압축 방안과, V-PCC 비트스트림을 저장하고 전송하기 위한 ISOBMFF 캡슐화 방안에 대한 표준화가 진행되고 있다. V-PCC는 기존의 2차원 비디오 코덱을 이용하기 위해 3차원 포인트 클라우드 데이터를 투영하여 2차원 패치를 생성하고, 생성된 패치를 2차원 그리드에 배치하여 2차원 이미지를 생성한다. 이 때, 생성되는 2차원 이미지는 패치의 모양 차이와 인코딩의 효율성 때문에 Group of Picture(GOP)마다 다른 크기를 갖는다. 이러한 이미지 크기의 차이는 반복적인 디코더 초기화를 유발하여 송신기와 수신기 모두에 큰 부담을 발생시킨다. 이에 본 논문에서는 비트레이트와 메타데이터를 적응적으로 제어하여 V-PCC 비트스트림을 반복적인 디코더 초기화 없이 안정적으로 송수신 하기 위한 Global grid 기반 V-PCC 전송 방안을 제안한다.

• Journal of the Korean Society of Radiology
• /
• v.15 no.7
• /
• pp.1065-1072
• /
• 2021

In Computed Tomography, abdominal examination showed the highest proportion of use, and effort of reducing the radiation dose is required. Recently introduced Iterative Reconstruction(IR) is repetitive reconstruction technique of Computed Tomography. SIEMENS' IR, ADMIRE and GE's IR, ASIR-V, were used in this examination. Noise, % Contrast, and High contrast resolution were measured by using ACR phantom for image quality evaluation. In addition, CTDI_vol and DLP displayed in the CT device were used for dose evaluation. When FBP and IR were compared, stage 2 to stage 5 of ADMIRE and 10, 30, 50, 70, and 90% of ASIR-V were applied, noise could be reduced from a minimum of 0.46 to a maximum of 2.38 in ADMIRE compared to FBP, and noise from a minimum of 0.51 to a maximum of 2.5 in ASIR-V compared to FBP. Also, % Contrast and High contrast resolution of FBP and IR were no statistical difference. When IR was used for abdominal CT examination, the radiation dose of ADMIRE is reduced by 25.39% compared to the radiation dose of FBP. Also, the radiation dose of ASIR-V is reduced by 16.61% compared to the radiation dose of FBP. In conclusion, it is believed that if IR is applied during abdominal CT examination, the radiation dose can be reduced without deteriorating the image quality.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.9 no.2
• /
• pp.121-124
• /
• 2010

In athletes, repetitive low-energy impacts in plantar lesion lead often to tendinitis, stress fracture, or overuse syndrome. The major cause of heel pain in athletes is plantar fasciitis. And it is most often attributable to repetitive low energy impact, but the vast majority patients with heel pain achieve symptomatic relief with conservative treatment and return to full activities. Not commonly, Nerve entrapment may be occurred from repetitive low energy trauma in athletes, and is not as easily diagnosed. The authors observed a basketball player who complained of chronic heel pain that do not respond to conservative treatment, he had the lesions both plantar fasciitis and lateral plantar nerve entrapment. The authors described an unusual mechanism of entrapment of the lateral plantar nerve combined with a chronic plantar fasciitis in a basketball player and reported with review of literature.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.141-148
• /
• 2023

The algebraic reconstruction technique is one of the reconstruction methods in CT and shows good image quality against noise-dominant conditions. The number of iteration is one of the key factors determining the execution time for the algebraic reconstruction technique. However, there are some rules for determining the number of iterations that result in more than a few hundred iterations. Thus, the rules are difficult to apply in practice. In this study, we proposed a method to determine the number of iterations for practical applications. The reconstructed image quality shows slow convergence as the number of iterations increases. Image quality 𝜖 < 0.001 was used to determine the optimal number of iteration. The Shepp-Logan head phantom was used to obtain noise-free projection and projections with noise for 360, 720, and 1440 views were obtained using Geant4 Monte Carlo simulation that has the same geometry dimension as a clinic CT system. Images reconstructed by around 10 iterations within the stop condition showed good quality. The method for determining the iteration number is an efficient way of replacing the best image-quality-based method, which brings over a few hundred iterations.

• Proceedings of the Korea Contents Association Conference
• /
• 2015.05a
• /
• pp.117-118
• /
• 2015

콘셉트 앨범에서 음악적 연출을 위한 기법으로 앨범 내 서로 다른 곡에서 사용한 반복적 음악 요소를 사용한다. 리프, 솔로, 멜로디, 화성 진행의 반복적 사용을 통하여 각각의 곡들이 콘셉트 앨범 내에서 연결되는 구조를 만든다. 이러한 연결 구조를 통하여 음악적 기법과 내러티브의 연관성을 찾는다. 연관성을 통하여 콘셉트 앨범의 음악적 연출과 내러티브 표현의 방법을 분석한다.

• Culinary science and hospitality research
• /
• v.19 no.5
• /
• pp.206-224
• /
• 2013

The purpose of this study was to examine the formation of customer's repeated use that is real long-term commitment in franchise/chain coffee shops. 457 effective samples were analyzed using PASW 18.0 and AMOS 18.0. The results of the analysis of the relationships between user experience, customer satisfaction, customer commitment and repeated use are as follows. First, it was presented that atmosphere, price fairness and coffee product quality had a positive impact on customer satisfaction. Second, customer satisfaction had a positive impact on customer commitment and repeated use. Finally, there was the mediating effect of continuous commitment between customer satisfaction and repeated use. Based on the results of the above analysis, the managerial implications for increasing repeated use of coffee shops are as follows. First, the strategy for enhancing performance of user experience is to try to improve atmosphere(facilities, ambient/lighting), price fairness, coffee product quality(taste, flavor, temperature). Second, the strategy for forming repeated use is to enhance customer commitment(affective commitment, continuous/normative commitment).

• Journal of the Korea Computer Industry Society
• /
• v.5 no.2
• /
• pp.311-324
• /
• 2004

Software development undergoes a number of iterations and each iteration forms its own cycle going through requirement analysis, scheme and design, implementation and finally test and evaluation. In this iterated development process, executable releases are produced, improved and eventually developed to a complete system, going through this particular development cycle. Compared to the conventional process, the advantage of rapid iterative development process lies in reducing risk factors in early stage and responding to changes very flexibly. In addition, highly reusable, the process can improve capabilities of the development team while the project is being carried out. As a result, overall balance in quality is secured. The objective of this paper is the research of rapid development process and its case studies showing how to adapt the rapidly changing customer requirements and to transform those requirements into the project timely and adequately. The proposed process is focused on the common and core activities of NET-based MarMIIII, MSF/CD, XP, Agile, PSP and TSP

• Journal of the Korean Geotechnical Society
• /
• v.25 no.8
• /
• pp.95-106
• /
• 2009

This study was intended to identify the effect of the wetting on a long-term compression settlement of the rock/soil mixture used as fill material, depending on compaction and grading conditions. The relatively large settlement happened under the fully-submerged condition, and a repeated settlement was monitored when moisture content increased over and over again like the rainfall infiltration. In case of the materials without fine fractions or compacted in wet condition, the settlement caused by wetting was relatively low. In conclusion, the long-term compression settlement of granular (rock/soil mixture) fill material is more affected by the increase of water content and temperature change (freezing and thawing) than creep.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.4
• /
• pp.119-130
• /
• 2012

Recently, the software system is getting complicating and the customers are requiring faster development. For the traditional sequential approach can't against this problem iterative approach is used instead. For the representative iterative approach, there is RUP (Rational's Unified Process). However, RUP standard practical methods are phase, iteration, and disciplines, sequentially. As a result, there's some waste of manpower when a discipline is executed in an iteration, it has to wait till the next same discipline is executed. There are linear approach, sequential approach, overlapped iteration approach, and time-boxed iteration for the efficient execution of RUP. However, they have some problems such as waste of manpower or difficulty in the project management. This paper suggests a method about how to execute the disciplines as a concurrent type. The concurrent approach prevents the waste of manpower and solves the difficulty of project management.

• Korean Journal of Cognitive Science
• /
• v.21 no.4
• /
• pp.603-625
• /
• 2010

Neural representation of a visual object is distributed across visual cortex and overlapped with those of many other objects. Thus repeating an object facilitates the recognition of the object while it impairs the recognition of other objects. These effects are called repetition priming and antipriming, respectively. Two experiments investigated a new phenomenon of repetition antipriming, in which a repeated object itself is antiprimed. The learning stage presented object pictures which were degraded at various levels. Participants determined how recognizable each object was. Then, the test stage presented the intact version of the object pictures and made participants to perform a categorization task. Both Experiment 1 and 2 found that the processing of the objects that had been recognized were facilitated (repetition priming) while the processing of the objects that had been perceptually ambiguous were impaired (repetition antipriming). These findings suggest that experiencing a perceptually ambiguous object might enhance the connection between feature-level representations and multiple object-level representations, which impairs the subsequent recognition of the repeated object.