• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.156-163
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• 2019

As a primitive immersive video technology, a three degrees of freedom (3DoF) $360^{\circ}$ video can currently render viewport images that are dependent on the rotational movements of the viewer. However, rendering a flat $360^{\circ}$ video, that is supporting head rotations only, may generate visual discomfort especially when objects close to the viewer are rendered. 3DoF+ enables head movements for a seated person adding horizontal, vertical, and depth translations. The 3DoF+ $360^{\circ}$ video is positioned between 3DoF and six degrees of freedom, which can realize the motion parallax with relatively simple virtual reality software in head-mounted displays. This article introduces the standardization trends for the 3DoF+ video in the MPEG-I visual group.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.51-58
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• 2021

Three degrees of freedom plus(3DoF+) and six degrees of freedom(6DoF) system, which supports a user's movements in graphical and natural scene-based virtual reality, requires multiple high-quality and high-resolution videos to provide immersive media. Previous video quality assessment methods are not appropriate for the 3DoF+ and 6DoF system assessment because different types of artifacts occur in these systems which are not shown in the traditional video compression. This paper provides the performance assessments of several quality assessment methods in 3DoF+ system. Furthermore, this paper presents a super metric, which combines multiple quality assessment methods, thereby it showed a higher correlation coefficient with the subjective quality assessment than the previous methods. Experimental results on 3DoF+ immersive video showed 0.4513 gain on correlation coefficient with subjective quality assessment compared to that of peak signal-to-noise ratio(PSNR).

• Journal of Broadcast Engineering
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• v.24 no.5
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• pp.743-754
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• 2019

System for three degrees of freedom plus (3DoF+) and 6DoF requires multi-view high resolution 360 video transmission to provide user viewport adaptive 360 video streaming. In this paper, we implement 3DoF+ 360 video compression system which removes the redundancy between multi-view videos and merges the residual into one video to provide high quality 360 video corresponding to an user's head movement efficiently. Implementations about 3D warping based redundancy removal method between 3DoF+ 360 videos and residual extraction and merger are explained in this paper. With the proposed system, 20.14% of BD-rate reduction in maximum is shown compared to traditional high-efficiency video coding (HEVC) based system.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.4
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• pp.295-307
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• 2002

Water temperature, salinity, and DO concentration were measured vertically in the Chinhae-Masan Bay over the course of 1 year. The characteristics of the stratification were analysed using the measured water temperature and salinity data. The vertical DO concentration changes were also analysed through consideration of the degree of stratification and the level of sediment pollution. The results of the analyses show that the thermal stratification appears just before April and disappears after October. The salinity differences between the surface and the bottom were 3.9(equation omitted), 9.3 (equation omitted), 4.3(equation omitted) in April, August, and October, respectively. The DO concentration change averaged over water depth was 2.6(mg/L) in April; 8.3(mg/L) in June: 5.9(mg/L) in August; 7.2(mg/L) in September; and 4.4(mg/L) in October. The DO concentration changes were closely related to the levels of contamination and also to the effect of the mass-transfer inhibition between the surface and bottom layers due to the thermal and density stratification.

• Journal of Broadcast Engineering
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• v.25 no.2
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• pp.185-191
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• 2020

MPEG-I is actively working on standardization on the immersive video coding which provides up to 6 degree of freedom (6DoF) in terms of viewpoint. In a virtual space of 3DoF+, which is defined as an extension of 360 with motion parallax, looking at the scene from another viewpoint (another position in space) requires rendering an additional viewpoint using multiple videos included in the 3DoF+ video. In the MPEG-I Visual workgroup, efficient coding methods for 3DoF+ video are being studied, and they released Test Model for Immersive Video (TMIV) recently. This paper presents a patch packing method which packs the patches into atlases efficiently for improving coding efficiency of 3DoF+ video in TMIV. The proposed method improves the reconstructed view quality with reduced coding artifacts by introducing guardbands between patches in the atlas.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.51-58
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• 1981

Hitherto 44 species belonging to 19 families of spiders have been reported at Ulreung-do on the East Sea. Korea. The authors have investigated spider fauna, through out the Ulreung-do, during July 25, August 3. 1975 and July 30, August 7, 1980. The foundings were as followings. 1) In this report, 132 species of 74 genera, including 3 undetermined species, belonging to 25 families of spiders are tabulated by the aid of published data and collections of the authors. Eighty six species are added to the fauna, of which 2 species are new to Korea. as follows; Porrhomma montanum Jackson. 1918, Clubiona neglecta O.P. Cambridge, 1862. The spider fauna of Ulreung-do includes 18 nothern species $(14.0\%)$, 8 southern species $(6.2\%)$. 7 cosmopolitan species $(5.4\%)$ and 84 Palaearctic temperate species $(65.1\%)$. The predominant species are Araneids. Thridiids, especially Cyclosa japonica Boes. et Str. are found in large numbers all over this island. Linyphiids and Lycosids are relatively few in number. 3) The common species to comparative area and foreign countries are as follows; Ulreung-do/Jookbyeon...76 species$(43.3\%)$ Ulreung-do/Jeju-do...95 species$(40.6\%)$ Ulreung-do/Heuksan do...61 species$(35.7\%)$ Ulreung-do/Deogjeog-do...51 species$(31.7\%)$ Ulreung-do/Tsushima Isl....71 species$(30.3\%)$ Ulreung-do/Japan...112 species$(11.3\%)$ Ulreung-do/main China...59 species $(6.5\%)$ 4) The ecological distribution are as follows; The seashore region...81 species$(62.8\%)$ The evergreens region...73 species$(56.6\%)$ The highiands region...64 species$(49.6\%)$ The valleys region...49 species$(38.0\%)$ The basin region...23 species$(17.8\%)$ 5) The noticeable one of geographical distribution in this island, are as follows; Nesticus quelpartensis Paik et Namkung, 1969, Conoculus simboggulensis Paik, 1971.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.479.2-479.2
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• 2006

• Journal of IKEEE
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• v.19 no.3
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• pp.415-423
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• 2015

The DO-178C guide, which is referenced as the software development guide when a certification of the airworthiness in the commercial airplane is acquired by FAA in US, is recently referenced for the local military aircraft airworthiness. This indicates that when the auditor of the military aircraft airworthiness looks over the software development documents, the auditor reviews if all of the documents are verified in accordance with the DO-178C guide. However, when we developed the military aircraft intercom, We developed its control software in accordance with the CMMI level 3, since there were no requirements for the compliance of the DO-178C guide. Therefore, When we consider the airworthiness of this intercomm system, The analysis for how much the software development based on the CMMI level 3 is different from the DO-178C guide is needed to prepare the essential software documents additionally. Thus, This study analyzes the differences between CMMI level 3 and DO-178C guide and provides that which data on the CMMI level 3 is necessary for the compliance of the aircraft airworthiness comparing with the DO-178C. The analyzed result can be applied at the software development of the other military aircraft avionics equipment based on the CMMI model environment considering the compliance of the military aircraft airworthiness.

• Journal of Oral Medicine and Pain
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• v.15 no.1
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• pp.91-104
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• 1991

After alkaline slab polyacrylamide gel electrophoresis and 3.3'-DMB staining of parotid saliva from 48 peoples in Ullung-do and 35 peoples in Jawall-do, the author have got following conclusions. 1. The gene frequencies of Proline-rich protein in Ullung-do were Pr1 =0.719, Pr2=0.281 2. The gene frequencies of Proline-rich protein in Jawall-do were Pr1=0.671, Pr2=0.329 3. The gene frequencies of Double band protein in Ullung-do were Db+=0.087, Db-=0.913 4. The gene frequencies of Double band protein in Jawall-do were Db+=0.0.106, Db-=0.0.894 5. The gene frequencies of Pa protein in Ullung-do were Pa+=0.179, Pa-=0.821 6. The gene frequencies of Pa protein in Jawall-do were Pa+=0.167, Pa-=0.833 7. The gene frequencies of Pr1 of Ullung-do and jawall-do were lower than those of Pr1 in Seoul and Onyang, but similar to those of Pr1 in kangnung and Cheju. 8. The gene frequencies of Db- of Ullung-do and Jawall-do were much higher than those of Db+ in Japanese, Chinese and other populations in Korean.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.11-17
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• 2009

This paper deals with the estimation performance DoA (Direction of Arrival) using the 3D adaptive array antenna in W-CDMA signal. For this, we proposed the 5 types of 3D array antenna, and appied for the MUSIC in order to the estimation of DoA algorithm for that antenna, commonly, then the DoA estimation error was used for the estimation performance. In the mobile communication and radio positioning service, performing the spatial filtering after the DoA estimation in array antenna, the quality of receiving signal can improve by the nulling or minimization of interfering signal which is from the undesired direction and the forming of beam which is from the desired direction. The result of DoA estimation and the DoA estimation error by varying the signal to noise ration and the number of interfering signal and power of each type antenna was calculated by computer simulation. As a result of simulation, the other propose antenna has good performance excluding the stack 3D antenna in DoA estimation and the Curved-B type antenna has more superior performance when increasing the number of interfering signal and power in the DoA estimation error.