• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.316-323
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• 2013

The use of artificial roughness in various forms of shapes and sizes is the most common and effective way to improve the performance of a flat-plate solar collector. In the present study, numerical analysis on heat transfer and pressure drop was performed in a rectangular channel with various rib arrays. The uniform heat flux is applied to the channel from the upper side. The forms of ribs considered in this study were rib $90^{\circ}$, groove $90^{\circ}$, groove $60^{\circ}$, baffle $90^{\circ}$, baffle $60^{\circ}$, wave $90^{\circ}$ and wave $60^{\circ}$. Air is the working fluid, and the Reynolds number ranges from 3200 to 17800. Nusselt number and friction factor were investigated to predict the performance of the system with various type of ribs. The average Nusselt number and pressure drop were increased with the increase of velocity in all types of ribs. The highest heat transfer and pressure drop occurred for the baffle $90^{\circ}$, but highest performance factor considering heat transfer and pressure drop together occurred for the groove $60^{\circ}$. Therefore, heat transfer and pressure drop should be considered together when a flat plate solar collector is designed.

• The Journal of Industrial Distribution & Business
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• v.10 no.1
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• pp.59-67
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• 2019

Purpose - The Millennial Generation, which grew in the wake of the spread of the Internet and rapid changes in the media environment, is rapidly moving from the traditional broadcasting environment to the Internet-broadcasting environment in terms of content acceptance. With the emergence of UGC (User-generated content), the change in the status of single-person content creators enables the growth of multi-channel networks (MCN), a new content-distribution platform and an agency concept for single creators. Youtube-based MCN produces multiple single star producers and casts and provides its own video series through Youtube. It is also emerging as a major M&A target for global media providers in terms of providing content to a wide range of consumers with the same interests and consumption characteristics. In addition, for the Millennials generation, which are part of their lives, MCN is becoming the most suitable media for TGIF (Twitter, Google, i-phone, Facebook). Accordingly, this study defines newly emerging MCNs and analyzes the factors for accepting MCN-produced content based on the push-pull-mooring (PPM) model. Research design, data, and methodology - An empirical analysis is performed through a questionnaire survey. For this purpose, 204 people who have experience of watching MCN were studied. Collected data is processed through analysis of a structural equation model using R to test the hypothesis. Results - For the MCN service to become an alternative to existing media, it is necessary to continuously promote cultural diversity and diversity of attempts that conventional media cannot provide. It is the attractiveness of the alternative that has the greatest influence on the intention to switch to a MCN service. When we look at MCN content so far, certain patterns such as game progress, introduction, food, and chat rooms have already appeared. We need to overcome this and develop a completely new conceptual content that we have never seen before. This requires a more generous viewer perception of the topics covered. For diversity, linguistic and verbal violence should be tolerant in common sense to provide a foundation for securing cultural diversity. Conclusions - In this study, we tried to develop a comprehensive approach to the substitution effect of MCN. In terms of academic achievement, the PPM model is used to enhance the utilization of media and broadcasting. Practical implications are to provide an analytical framework for verifying alternative or complementary effects when viewers switch to MCN.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.151-160
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• 2017

Among the methods of developing tourist spots and culture as the experience contents, it is a common method to display high-quality video images on a large display, and it is necessary to make a special difference between the participant's active participation and the visual experience in other regions. In this paper, using the single molecular OLED and active type, the regional tourist spots blend transparent OLED dual-layer display systems with the extended image implementation and augmented interaction techniques to give the participants a real-world experience, such as directing to new experiences and beautiful sights. In this paper, additional images and UI layers are applied to the layers of the images to allow visitors to experience sightseeing information, weather, maps, accommodations, festivals and photo materials with image. In addition to the dual-layer system, it also added a multi-display system that additionally has one vertical 55-inch display on each side, adding to the experience the immersive experience and interface interlocking fun. By using transparent OLED, dual layer panel and 3-channel Multi-image playback technique, the augmented type experience contents which can experience the local attractions in Jeollanamdo province in Korea at all time without any limitation of time and space were developed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.747-756
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• 2014

In this paper, we propose a path loss model with the multiple antennas using diversity effect. Currently wireless communication systems use the multiple antennas in order to improve the channel capacity or diversity gain. However, until recently, many researches on path loss model only consider geographical environment between the transmitter and the receiver. There is no study about path loss model considering diversity effect. Nowaday wireless communication use the multiple antennas and we in common find examples using diversity scheme that is method in order to enhance a channel capacity. Moreover we anticipate that it work harder in future researches. But in this communication system, path loss model isn't established that predict strength of received signal. So, in order to predict strength of received signal, we take changing SNR by diversity gain. When exceeding the number of antennas of receiver are 7 in proposed model, diversity effect is saturated. Therefore we consider the number of antenna of receiver until 10. We find RMSE between proposed model and value of calculation is 1. We calculate the diversity gain by conventional BER curve. Proposed model can predict loss of received signal in system using multiple antennas.

• Journal of Life Science
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• v.13 no.6
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• pp.805-813
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• 2003

cDNA encoding somatolactin (SL) was obtained by RT-PCR from pituitary glands of rock bream (Oplegnathus fasciatus). The full length cDNA of rock bream somatolactin (rbSL) is 1636 bp long. It contains a 696 bp open reading frame encoding a signal peptide of 24 amino acids (an) and a mature protein of 207 aa. rbSL has seven cysteine residues$(Cys^{5},\; Cys^{15},\; Cys^{42},\; Cys^{65},\; Cys^{181},\; Cys^{198}\; $and $Cys^{206})$ and two potential N-glycosylation sites at positions $Asn^{121}$and $Asn^{153}$. The rbSL shares 61.1∼92.6% amino acid sequence similarities and 63∼92.6% nucleotide sequence identities with other teleost SLs, except for goldfish and channel catfish SL. Amino acid sequence alignment revealed that rbSL has four conserved domains $(A_{SL},\; B_{SL},\; C_{SL}and\; D_{SL})$ common to all SLs. Out of these domains, $(A_{SL},\; B_{SL},\; C_{SL}and\; D_{SL})$, are also conserved in all teleost growth hormones and prolactins. The cDNA of rbSL has been cloned into pET expression vector in order to produce recombinant rbSL in E. coli BL2l(DE3) cells. The recombinant protein showed a molecular weight of 27 kDa in SDS-PAGE.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1336-1347
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• 1991

In this paper, The PC interface for packet terminal of ISDN is designed and implemented in order to build packet communication networks which share computer resources and exchange informations between computer in the ISDN environment. The PC interface for packet terminal of ISDN constitutes S interface handler part which controls functions of ISDN layer1 and layer 2, constitutes packet handler part which controls services of X.25 protocol in the packet level.Where, The function of ISDN layer1 provides rules of electrical and mechanical characteristics, services for ISDN layer 2. The function of ISDN layer 2 provides function of LAPD procedure, services for X.25 The X.25 specifies interface between DCE and DTE for terminals operrating in the packet mode. The S interface handler part is orfanized by Am 79C30 ICs manufactured by Advanecd Micro Devices. ISDN packet handler part is organiged by AmZ8038 for FIFO for the purpose of D channel. The common signal procedure for D channel is controlled by Intel's 8086 microprocessor. The S interface handler part is based on ISDN layer1,2 is controlled by mail box in order to communicate between layers. The ISDN packet handler part is based on module in the X.25 lebel. The communication between S interface handler part and ISDN packet handler part is organized by interface controller.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.13-25
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• 2019

Since reaching the top in the Billboard Main Album Chart 'Billboard 200' with Love Yourself: Tear in May of 2018, BTS once again took first place after just three months in the 'Billboard 200'(September 3, 2018) with the repackaged album Love Yourself: Answer. It opened the doors to the 'Hallyu 4.0' by conquering the main Billboard Chart with a song sung in Korean. BTS rose to the top on the 'Billboard 200' twice, thus being recognized globally for their musical talent(song, dance, promotion, etc.), and took their place in the mainstream music market of the world. BTS moved away from intuitive interaction such as mysticism, abnormality, irregularity, etc. but instead created their own world(BTS Universe) with fans around the world through two-directional communication such as consensus, sharing and co-existence. They are recognized as artists that went beyond being an idol group that simply released a few hit songs that had now elevated popular music to a new form of art. In result, they retained a highly loyal global fan base(A.R.M.Y.) and they are continuously creating good influence with them. This study analyzed the success factors of BTS using the S-M-C-R-E model as follows. ① Sender: BTS'7-person 7-colors fantasy and 'All-in-one storytelling' strategy of producer Bang Shi-hyuk ② Message: Create global consensus of 'you' rather than 'me' ③ Channel: Created real-time common grounds with global fans through social network platforms such as Youtube, Facebook and Instagram ④ Receiver: Formed highly loyal global fandom(A.R.M.Y.) that extends outside of Korea and Asia ⑤ Effect: Created additional economic value and spread good influence

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.385-390
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• 2016

ELoran Systems can provide Position, Navigation, and Time services with comparable performance to Global Positioning Systems (GPS) as a back up or alternative system. High timing and navigation performance can be achieved by eLoran signals because eLoran receivers use "all-in-view" reception. This incorporates Time of Arrival (TOA) signals from all stations in the service range because each eLoran station is synchronized to Coordinated Universal Time (UTC). Transmission station information and the differential Loran correction data are transmitted via an additional Loran Data Channel (LDC) on the transmitted eLoran signal such that eLoran provides improved Position Navigation and Timing (PNT) over legacy Loran. In this paper, we propose a technique for adapting the delay time compensation values in eLoran timing receivers to provide precise time comparison. For this purpose, we have designed a system that measures time delay from the crossing point of the third cycle extracted from the current transformer at the end point of the transmitter. The receiver delay was measured by connecting an active H-field, an E-field and a passive loop antenna to a commercial eLoran timing receiver. The common-view time transfer technique using the calibrated eLoran timing receiver improved the eLoran transfer time. A eLoran timing receiver calibrated by this method can be utilized in the field for precise time comparison as a GNSS backup.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.60-69
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• 2020

Purpose: Cavity growth process monitoring is to periodically monitor changes in common size and topography for general and observational grades to predict the rate of common growth. The purpose of this study is to establish a systematic cavity management plan by evaluating the general and observational class community in a non-destructive method. Method: Using GPR exploration equipment, the acquired surface image and the surrounding status image are analyzed in the GPR probe radargram in depth, profile, and cross section of the location. The exact location is selected using the distance and surrounding markings shown on the road surface of the initial detection cavity, and the test cavity is analyzed by calling the radar at the corresponding location. Result: As a result of monitoring tests conducted at a cavity 30 sites of general and observation grade, nine sites have been recovered. Changes in scale were seen in 21 cavity locations, and changes in size and grade occurred in 13 locations. Conclusion: The under road cavity is caused by various causes such as damage to the burial site, poor construction, soil leakage caused by groundwater leakage, waste and ground vibration. Among them, indirect factors could infer the effects of groundwater and localized rainfall.

• The Journal of Engineering Geology
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• v.25 no.3
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• pp.349-356
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• 2015

Although geophysical methods are useful and generally provide valuable information about the subsurface, it is important to recognize their limitations. A common limitation is the lack of sufficient contrast in physical properties between different layers. Thus, multiple methods are commonly used to best constrain the physical properties of different layers and interpret each section individually. Ground penetrating radar (GPR) and shallow seismic reflection (SSR) methods, used for shallow and very shallow subsurface imaging, respond to dielectric and velocity contrasts between layers, respectively. In this study, we merged GPR and SSR data from a test site within the Cheongui granitic mass, where the water table is ~3 m deep all year. We interpreted the data in combination with field observations and existing data from drill cores and well logs. GPR and SSR reflections from the tops of the sand layer, water table, and weathered and soft rocks are successfully mapped in a single section, and they correlate well with electrical resistivity data and SPS (suspension PS) well-logging profiles. In addition, subsurface interfaces in the integrated section correlate well with S-wave velocity structures from multi-channel analysis shear wave (MASW) data, a method that was recently developed to enhance lateral resolution on the basis of CMP (common midpoint) cross-correlation (CMPCC) analysis.