A comparative study of KakaoStory and Facebook: Focusing on use patterns and use motives

Before global SNS services, such as Facebook and Twitter, were introduced in Korea, Cyworld monopolized the Korean SNS market. However, Cyworld was left behind because it maintained a closed system, which no longer satisfied users. KakaoTalk, a popular Korean mobile messaging application has allowed the messenger itself to become a platform for various services including SNS. KakaoStory began as a photo-based SNS service; by integrating with KakaoTalk’s profile pictures, it has become the most popular SNS in Korea. This study focuses on the usage patterns of SNS users to analyze how KakaoStory became one of the most popular SNSs in Korea. In particular, we have examined the differences in usage patterns between KakaoStory and Facebook, and the primary reasons why Korean users select one of these two social networking sites instead of the other. We conducted an exploratory comparison between KakaoStory and Facebook, specifically focusing on the usage patterns and motivations of both sets of users. We also analyzed how the different usage motivations linked to these two social media networks have influenced usage patterns.     

Analysis of the psychological traits,Facebook usage,and Facebook addiction model of Taiwanese university students

The purposes of this study are to (1) identify the role of the psychological traits of university students in Facebook addiction and Facebook usage; and (2) explore the correlation between Facebook usage and Facebook addiction. This study treated 241 university students in Taiwan as the research subjects, and adopted the Rosenberg’s self-esteem scale, Lai’s personality test, a Facebook usage scale, and a Facebook addiction scale (FAS). The structured equation modeling (SEM) was used for data analysis. The results showed that: (1) self-inferiority can significantly predict Facebook usage; and (2) having a depressive character and Facebook usage can significantly predict Facebook addiction. Finally, discussion was conducted on the findings, and relevant suggestions were proposed for schools, students, and future studies.     

Determinants of the intention to use Buy-Online,Pickup In-Store (BOPS): The moderating effects of situational factors and product type

Despite the wider introduction of the buy online and pick up in-store (BOPS) service by retailers, research on BOPS is still sparse, especially those from the consumer perspective. This paper employs the scenario-based factorial survey method to investigate how the perceived characteristics of innovation and the perceived risk of online shopping influence the consumers’ intention to use BOPS while also considering the moderating effects of situational factors (location convenience) and product type (involvement). Our findings indicated that the consumer perceptions of relative advantage, complexity, compatibility, and risks involved in online shopping are important antecedents to intention to use BOPS, and that these relationships were significantly moderated by locational convenience and product involvement. The implications of the findings and suggestions for future research are discussed in detail.     

An experimental study of the influence of boundary conditions on the Gunn effect

The electrical characteristics of long inhomogeneous bulk negative differential mobility (NDM) semiconductor elements (n-GaAs and n-InP) exhibiting various modes of current instabilities at low microwave frequencies have been experimentally observed. Measurements were made of the time-dependent sample current and voltage and of the prethreshold electric-field distribution within the sample. The measurements were made under conditions in which the configuration of the circuit, the properties of the boundary of the NDM element, the sample geometry, the temperature, and the magnetic field were varied. We have obtained excellent agreement between the experimental results and a model in which the sample is assumed to have an assigned value for the electric field at the cathode boundary. Different modes of instability may be accurately modeled by choosing an appropriate value for this field. Three regions of behavior may be identified which correspond to three regions for the cathode boundary field. These regions are 1) cathode boundary field Ecless than the threshold electric field Epfor the onset of NDM; the samples are likely to operate as bulk oscillators, 2)E_{c} > E_{p}but less than the electric field Evcorresponding to the onset of the saturated electron-drift velocity; the samples operate in the Gunn domain mode with a peak-to-valley ratio determined by Ec, and 3)E_{c} > E_{v}the samples yield saturating current versus voltage curves and only weak oscillations are possible.     

The survival strategy of branded content in the over-the-top (OTT) environment: Eye-tracking and Q-methodology approach in digital product placement

The goal of this paper is to discuss how branded content may be adopted to succeed with the over-the-top (OTT) market using digital product placement (PPL). Analyzing the eye movements of 34 subjects with manipulated experimental materials we also examined their fundamental attitudes toward branded content using digital PPL in the OTT environment. In the first part of the experiment, eye-movements and fixation durations on our nine equally divided areas of interest (AOIs) were analyzed. In the second part, we used the Q-method to classify users’ underlying factors for the digital PPL into three types, namely pragmatism, conservatism, and rationalism. Despite intensive differences, there are some common attitudes among these three types with respect to regulations. Based on three research questions, our results recommend that both practitioners and researchers should identify the physically optimized places that would attract users’ visual attention based on their brand characteristics. At the same time, they should formulate psychological strategies whereby users are unable to recognize the intentional exposure of a particular brand or the brand becomes integral to the plot.     

An experimental study on the universality of visual vocabularies

Bag-of-visual-words has been shown to be a powerful image representation and attained success in many computer vision and pattern recognition applications. Usually for a given classification task, researchers choose to build a specific visual vocabulary, and the problem of building a universal visual vocabulary is rarely addressed. In this paper we conduct extensive classification experiments with three features on four image datasets and show that the visual vocabularies built from different datasets can be exchanged without apparent performance loss. Furthermore, we investigate the correlation between the visual vocabularies built from different datasets and find that they are nearly identical, which explains why they are universal across classification tasks. We believe that this work reveals what is behind the universality of visual vocabularies and narrows the gap between bag-of-visual-words and bag-of-words in text domain.     

On the effect of channel spacing,launch power,and regenerator placement on the design of mixed-line-rate optical networks

Due to the increasing heterogeneity and the growing volume of traffic, telecom backbone networks are going through significant innovations. Wavelength-division multiplexed (WDM) optical networks can now cost-effectively support the growing heterogeneity of traffic demands by having mixed line rates (MLR) over different wavelength channels.The coexistence of wavelength channels with different line rates, e.g., 10/40/100 Gbps, in the same fiber brings up various design issues: in this study, we focus on (1) choice of channel spacing; (2) choice of launch power; and (3) regenerator placement. Channel spacing affects the signal quality in terms of bit-error rate (BER), and hence affects the maximum reach of lightpaths, which is a function of line rates. Various approaches to set an opportunistic width of the channel spacing can be considered, viz., (i) uniform fixed channel spacing specified by the ITU-T grid (typically 50 GHz); (ii) different channel spacing for different line rates; or (iii) optimal value of channel spacing for all line rates that leads to minimum cost.The launch optical power of a signal is another important parameter that affects the network cost. Adjacent channels on different line rates, especially 10 Gbps and 100 Gbps, may exhibit serious degradation of signal quality and optical reach for both the channels due to cross-phase modulation (XPM) between them. Launch power plays a role in such a scenario as it governs the BER by affecting both the signal power and the noise power due to XPM. Moreover, intelligent choice of launch powers on different line rates can significantly reduce the number of regenerators required in the network. The tradeoff between placement of regenerators and choice of launch power is an important problem to address for MLR network design.In this work, we investigate the effects of channel spacing and launch optical power by evaluating the cost of a MLR network for different values of these parameters. We also study the interplay between regenerator placement and launch power. Our results show that (a) it is possible to identify optimal values of channel spacing for a minimum-cost MLR network design, and (b) controlling the power of 10 Gbps and 100 Gbps channels shows maximum sensitivity to the network cost.     

Theoretical and experimental study on the shape of laser beam in the Goos-H(a)nchen effect

在研究双面金属包覆波导对古斯-汉欣( Goos-Hinchen,G-H)位移的增强效应过程中,观察到了光束在发生古斯-汉欣侧向位移的同时光斑能量会重新分布的现象.为了研究其产生机理,采用高斯光束模型对其进行了模拟计算和实验验证,得到了在波长调谐时,反射光经历不同G-H位移时的光斑形态.结果表明,理论分析和实验结果是完全一致的,并预示着实验中用位置灵敏探测器在观测G-H位移时的局限性.这一结果预计对利用古斯-汉欣效应制作的各类光学器件的研究及应用是有帮助的.     

基于LAN的MANET无线信道仿真系统中拓扑变化、碰撞和噪声的模拟

介绍了在Windows系统中对MANET无线信道中碰撞和噪声的模拟，同时介绍了网络拓扑变化的模拟，分析了其实现的可行性，并给出了具体的实现方法。     

An experimental and theoretical study on the circuit properties of a cylindrical antenna in a hot lossy plasma

Experimental results on the input impedances and the current distributions of cylindrical antennas of various lengths in a large volume of hot lossy plasma are presented. A relatively simple theory based on an integral equation and a grid antenna model is developed. The theoretical results are in good qualitative agreement with the experiments. The theory is also compared to theories of some other researchers. Because of its simplicity, the present theory may prove useful in practical applications.     

User adaptation to interactive advertising formats: The effect of previous exposure,habit and time urgency on ad skipping behaviors

Due to commercial information loss of efficacy, social media advertising introduced skippable formats as an interactive function to attract customers. This empowerment of users could also favor the development of their skills and strategies to deal with online advertising, which may result in a lower advertising effectiveness. A study with 286 YouTube users was carried out to investigate this adaptation process to an advertising format by focusing on pre-roll skippable video ads. In contrast to advertisers’ approach (e.g. improving the persuasiveness of the ad), our research deepens on the ad skipping phenomenon from a human and context based perspective. In favor of an ad avoidance training effect, the findings show that participants previously exposed to a skippable ad are faster in taking the decision to watch or skip a subsequent ad. Participants’ skipping habits and time urgency are also revealed as main determinants of different ad skipping behaviors. This innovative research provides empirical support for the adaptation process leading people’s interrelation with interactive advertising formats. Practical and theoretical consequences are discussed for advancing on this underexplored topic.     

Theoretical and experimental study of the effect of InAs growth rate on the properties of QD arrays in InAs/GaAs system

The dependence of properties of quantum dot (QD) arrays in an InAs/GaAs system on the InAs growth rate has been investigated theoretically and experimentally. The derived kinetic model of the formation of coherent nanoislands allows the calculation of the average size, surface density of islands, and wetting layer thickness as functions of the growth time and conditions. Optical properties of InAs/GaAs QDs have been studied for the case of two monolayers (ML) of the material deposited at different growth rates. Predictions of the theoretical model are compared with the experimental data. It is shown that with two ML of the deposited material the characteristic lateral size of QDs decreases and the thickness of the residual wetting layer increases with rising growth rate.     

Gratifications of using Facebook,Twitter, Instagram,or Snapchat to follow brands: The moderating effect of social comparison,trust, tie strength,and network homophily on brand identification,brand engagement,brand commitment,and membership intention

Applying uses and gratifications theory (UGT), this study examined consumers’ use of one of four social networking sites (SNSs): Facebook, Twitter, Instagram, or Snapchat, for following brands, and their influence on brand community-related outcomes. Results (N = 297) indicated Snapchat users scored highest for passing time, sharing problems, and improving social knowledge, while Instagram users scored highest for showing affection, following fashion, and demonstrating sociability. Twitter users had highest brand community identification and membership intention, while Instagram users had highest brand community engagement and commitment. Attention to social comparison, SNS trust, tie strength, and homophily also significantly moderated the relationship between frequent use of each SNS to follow brands, and brand community-related outcomes. Implications for future research on SNS users’ goal-directed consumption behaviors are discussed.     

Comparative study on the effect of misalignment on bordered and borderless contacts

Continued shrinking of feature sizes in integrated circuits has raised increasing reliability concern. In order to achieve higher packing density, interconnects are migrating toward borderless contacts and vias. The penalty with the absence of metal extension, however, is the decrease in electromigration lifetimes. The issue is particularly critical when there is a misalignment between the contact and metal line, which may occur due to process variability. In this paper, we studied the effect of misalignment on the electromigration lifetimes for bordered and borderless contacts. We found that the misalignment effect becomes more pronounced in borderless contacts. We also studied the case of multiple contact configuration. The results indicate that electromigration lifetimes increase with increasing number of contacts in series. The experimental data is consistent with finite element modeling results.     

LD泵浦Nd:YAG晶体准三能级热效应理论与实验

对LD端面泵浦圆柱形Nd:YAG晶体产生946 nm激光的晶体热效应进行了分析.考虑晶体的准三能级结构和腔内传播功率的分布,对热转换系数进行了修改,得到了更符合实际情况的晶体内部温度场分布.当泵浦功率为15W时,晶体端面中心温度由未修改参数前的242.73℃升高到了387.43℃,提高了144.70℃.分别对修改参数前...     

An investigation on the effect of varying the load, mesh and simulation parameters in microwave heating applications.

The paper attempts to provide a generic proposal on the influence of various microwave load parameters based on results accumulated during an investigation using a specific microwave multimode heating cavity configuration. The results have been obtained by numerical analysis using the Finite Element Method within a 3-D environment. The load parameters considered were dielectric constant, loss factor, load thickness and load position. Load material properties are typical of those used in industrial relevant applications. Of the four load parameters investigated, the configuration with a high loss factor was seen to dominate the load impact regardless of load thickness, load position or dielectric constant. With decreasing loss factor or increasing load thickness, the influence of the dielectric constant increases. Minor adjustments in the load position (10%) is generally seen to have minimal impact for all load properties considered. The paper also investigates the numerical impact of varying load properties. As the dielectric constant increases, which requires a higher number of mesh elements, so does the average iterations per numerical cycle. The number of numerical cycles and time to reach a convergence is also seen to be inversely proportional to the load loss factor.     

激光选通成像系统MTF与SNR的仿真与实验研究

距离选通技术能有效提高主动成像系统的信噪比,但远距离选通成像系统的调制传递函数(MTF)和信噪比(SNR)与被动成像系统存在较大差异。分析了影响主动成像系统MTF与SNR的主要因素,推导了主动成像系统SNR与照明光强闪烁率的关系。分别使用氙灯和半导体泵浦的固体激光器进行了远距离主动成像实验,测得成像系统空间分辨率与湍流强度和光强闪烁率之间的关系与理论计算吻合。