• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.2
• /
• pp.618-633
• /
• 2014

Relay technology is becoming more important for mobile communications and wireless internet of things (IoT) networking because of the extended access network coverage range and reliable quality of service (QoS) it can provide at low power consumption levels. Existing mobile multihop relay (MMR) technology uses fixed-point stationary relay stations (RSs) and a divided time-frame (or frequency-band) to support the relay operation. This approach has limitations when a local fixed-point stationary RS does not exist. In addition, since the time-frame (or frequency-band) channel resources are pre-divided for the relay operation, there is no way to achieve high channel utilization using intelligent opportunistic techniques. In this paper, a different approach is considered, where the use of mobile/IoT devices as RSs is considered. In applications that use mobile/IoT devices as relay systems, due to the very limited battery energy of a mobile/IoT device and unequal channel conditions to and from the RS, both minimum energy consumption and QoS support must be considered simultaneously in the selection and configuration of RSs. Therefore, in this paper, a mobile RS is selected and configured with the objective of minimizing power consumption while satisfying end-to-end data rate and bit error rate (BER) requirements. For the RS, both downlink (DL) to the destination system (DS) (i.e., IoT device or user equipment (UE)) and uplink (UL) to the base station (BS) need to be adaptively configured (using adaptive modulation and power control) to minimize power consumption while satisfying the end-to-end QoS constraints. This paper proposes a minimum transmission power consuming RS selection and configuration (MPRSC) scheme, where the RS uses cognitive radio (CR) sub-channels when communicating with the DS, and therefore the scheme is named MPRSC-CR. The proposed MPRSC-CR scheme is activated when a DS moves out of the BS's QoS supportive coverage range. In this case, data transmissions between the RS and BS use the assigned primary channel that the DS had been using, and data transmissions between the RS and DS use CR sub-channels. The simulation results demonstrate that the proposed MPRSC-CR scheme extends the coverage range of the BS and minimizes the power consumption of the RS through optimal selection and configuration of a RS.

• Journal of the Korean Regional Science Association
• /
• v.35 no.4
• /
• pp.47-60
• /
• 2019

The purpose of this study is to analyze gender gaps in wage and job satisfaction according to skill characteristics and gender composition in occupation type. Most of the previous studies dealing with gender gaps in wage and job satisfaction have limitations in using a model at a single level. To overcome these limitations, this study integrated the analysis of worker level and job level variables through the application of hierarchical linear model. For the empirical analysis, the 20th year of the Korea Labor Institute Panel Survey and Korea Network for Occupations and Workers data used, factor analysis was utilized to derive cognitive, technical and physical skills. According to the empirical results, female workers in the metropolitan area showed lower average wage and job satisfaction than male worker. these gender gaps were alleviated in occupations which requiring a high level of cognitive skill, while deepening in occupation with a high occupational segregation. The purpose of this study is to derive implications for the policy aimed at reducing the gender gap in the labor market by analyzing the relationship between gender gaps in wage and job satisfaction according to skill characteristics and gender composition rates of wage workers in the metropolitan area.

• Korean Journal of Cognitive Science
• /
• v.28 no.1
• /
• pp.65-90
• /
• 2017

Rewards or penalties become informative only when contingent on an immediately preceding response. Our goal was to determine if the brain responds differently to motivational events depending on whether they provide feedback with the contingencies effective for learning. Event-related fMRI data were obtained from 22 volunteers performing a visuomotor categorical task. In learning-condition trials, participants learned by trial and error to make left or right responses to letter cues (16 consonants). Monetary rewards (+500) or penalties (-500) were given as feedback (learning feedback). In random-condition trials, cues (4 vowels) appeared right or left of the display center, and participants were instructed to respond with the appropriate hand. However, rewards or penalties (random feedback) were given randomly (50/50%) regardless of the correctness of response. Feedback-associated BOLD responses were analyzed with ANOVA [trial type (learning vs. random) x feedback type (reward vs. penalty)] using SPM8 (voxel-wise FWE p < .001). The right caudate nucleus and right cerebellum showed activation, whereas the left parahippocampus and other regions as the default mode network showed deactivation, both greater for learning trials than random trials. Activations associated with reward feedback did not differ between the two trial types for any brain region. For penalty, both learning-penalty and random-penalty enhanced activity in the left insular cortex, but not the right. The left insula, however, as well as the left dorsolateral prefrontal cortex and dorsomedial prefrontal cortex/dorsal anterior cingulate cortex, showed much greater responses for learning-penalty than for random-penalty. These findings suggest that learning-penalty plays a critical role in learning, unlike rewards or random-penalty, probably not only due to its evoking of aversive emotional responses, but also because of error-detection processing, either of which might lead to changes in planning or strategy.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.2
• /
• pp.9-14
• /
• 2020

This paper aims to figure out the impact of employee's travel experience on their happiness and motivations to work. To this end, targeting 405 employees in Daegu, Gyeongsangnamdo, and Gyeongsangbukdo, SPSS Statistics 18.0 program was applied to analyze. Frist, in travel experience depending on general characteristics of the targets, there was significant difference in gender, educational background, and occupation but there was significant difference in age, marital status, and average income. Second, there was difference in travel experience depending on frequency of domestic travel but no difference in terms of the period of stay. On the other hands, travel experience depending on frequency of overseas travel showd significant difference in sub-factor, human network experience. There was significant difference in overseas travel depending on period of stay. Third, travel experience showed positive relation in employee's motivation to work and happiness. Fourth, as a result of reviewing impact of travel experience on employee's motivations to work and happiness, sub-factors like emotional, behavioral, relational experiences affected motivations to work significantly. Emotional experience and cognitive experience didn't affect significant impact. And sub-factors of travel experience like emotional, cognitive, and behavioral experiences affected happiness significantly. Emotional and relational experience were not significant. From the research above, it turned out that travel experience gives happiness to employees and provokes positive thinking and their motivations to work.

• Journal of IKEEE
• /
• v.23 no.1
• /
• pp.280-288
• /
• 2019

In the CR-enabled MANET, routing paths can be easily destroyed due to node mobility and channel unavailability (due to the emergence of the PU of a channel), resulting in significant overhead to maintain/recover the routing path. In this paper, network caching is actively used for route maintenance, taking into account the properties of the CR. In the proposed scheme, even if a node detects that a path becomes unavailable, it does not generate control messages to establish an alternative path. Instead, the node stores the packets in its local cache and 1) waits for a certain amount of time for the PU to disappear; 2) waits for a little longer while overhearing messages from other flow; 3) after that, the node applies local route recovery process or delay tolerant forwarding strategy. According to the simulation study using the OPNET simulator, it is shown that the proposed scheme successfully reduces the amount of control messages for path recovery and the service latency for the time-sensitive traffic by 13.8% and 45.4%, respectively, compared to the existing scheme. Nevertheless, the delivery ratio of the time-insensitive traffic is improved 14.5% in the proposed scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.3
• /
• pp.361-366
• /
• 2012

This paper proposes a low power capacitor cross-coupled 5.2 GHz band low noise amplifier(LNA) using the current-reused topology with the TSMC 0.18 ${\mu}m$ CMOS process. The proposed 5.2 GHz band LNA uses a capacitor cross-coupled $g_m$-boosting method for reducing current flow of circuit and a current-reused topology to decrease total power dissipation. The parallel LC networks are used to reduce size of spiral inductors. The simulation results show high gain of 17.4 dB and noise figure(NF) of 2.7 dB for 5.2 GHz.

• Journal of the Korean Society for information Management
• /
• v.29 no.3
• /
• pp.145-167
• /
• 2012

The purpose of this study is to examine the causal relationships among self-efficacy, perceived usefulness, perceived ease of use, perceived playfulness, and reuse intention of SNS. The results of data analysis by structured equation model(SEM) indicate that self-efficacy significantly influences individual's perceived ease of use, perceived usefulness and perceived playfulness. Both perceived playfulness and perceived ease of use affects perceived usefulness on SNS. Individual's self-efficacy, perceived playfulness and perceived usefulness affect reuse intention of SNS. Based on the results, the theoretical and practical implications of this study are discussed.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.11
• /
• pp.59-68
• /
• 2010

In this paper, we present a new method to complete Dynamic Spectrum Access by modifying the reward function. Partially Observable Markov Decision Process (POMDP) is an eligible algorithm to predict the upcoming spectrum opportunity. In POMDP, Reward function is the last portion and very important for prediction. However, the Reward function has only two states (Busy and Idle). When collision happens in the channel, reward function indicates busy state which is responsible for the throughput decreasing of secondary user. In this paper, we focus the difference between busy and collision state. We have proposed a new algorithm for reward function that indicates an additional state of collision which brings better communication opportunity for secondary users. Secondary users properly utilize opportunities to access Primary User channels for efficient data transmission with the help of the new reward function. We have derived mathematical belief vector of the new algorithm as well. Simulation results have corroborated the superior performance of improved reward function. The new algorithm has increased the throughput for secondary user in cognitive radio network.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.6
• /
• pp.2479-2484
• /
• 2018

The filter bank multicarrier modulation (FBMC) technique is one of multicarrier modulation technique (MCM), which is mainly used to improve channel capacity of cognitive radio (CR) network and frequency spectrum access technique. The existing FBMC System contains serial to parallel converter, normal QAM modulation, Radix2 inverse FFT, parallel to serial converter and poly phase filter. It needs high area, delay and power consumption. To further reduce the area, delay and power of FBMC structure, a new clock gating technique is applied in the QAM modulation, radix2 multipath delay commutator (R2MDC) based inverse FFT and unified addition and subtraction (UAS) based FIR filter with parallel asynchronous self time adder (PASTA). The clock gating technique is mainly used to reduce the unwanted clock switching activity. The clock gating is nothing but clock signal of flip-flops is controlled by gate (i.e.) AND gate. Hence speed is high and power consumption is low. The comparison between existing QAM and proposed QAM with clock gating technique is carried out to analyze the results. Conversely, the proposed inverse R2MDC FFT with clock gating technique is compared with the existing radix2 inverse FFT. Also the comparison between existing poly phase filter and proposed UAS based FIR filter with PASTA adder is carried out to analyze the performance, area and power consumption individually. The proposed FBMC with clock gating technique offers low power and high speed than the existing FBMC structures.

• Archives of design research
• /
• v.19 no.3 s.65
• /
• pp.131-142
• /
• 2006

The purpose of this study is to develop an online community construct, which proposes an inclusive illustration of the structure of online communities, for online community designers. This study reviewed researches from psychology, sociology, management engineering, and practical reports to understand the characteristics and dynamics of online communities. The proposed online community construct visualizes the cognitive, affective, and behavioral aspects of online community. As the notion of community originates from geographical groups, and with the assumption that geographical community shares identical characteristics with online community, this study reviewed researches about geographical communities as a starting-point. Then the study went through three main perspectives (1) online community attributes, (2) sense of online community and (3) challenges of online community. Then this study proposed an online community construct that encompasses the reviewed frameworks. The online community can be seen as a congregation of members from two sources. One is from the 'Shared Goal' that meets the personal needs. Given the shared goal, members gather into the community without personal relationship and have more chances to feel the sense of belonging to their needs fulfillment or benefit. This befitting tendency leads to strengthening of membership. Public online forums fall under this classification. The other source is from the emotional connections that are already initiated by personal and casual contacts in the real world. The network of emotional connection can evolve into an online congregation of people under faint boundaries. Although there is no (or weak) shared goal, members are strongly bound to other members. Personal homepage or web log (blog) can be classified as an example of relationship-oriented community.