Machine-type communications: current status and future perspectives toward 5G systems

Machine-type communications (MTC) enables a broad range of applications from mission- critical services to massive deployment of autonomous devices. To spread these applications widely, cellular systems are considered as a potential candidate to provide connectivity for MTC devices. The ubiquitous deployment of these systems reduces network installation cost and provides mobility support. However, based on the service functions, there are key challenges that currently hinder the broad use of cellular systems for MTC. This article provides a clear mapping between the main MTC service requirements and their associated challenges. The goal is to develop a comprehensive understanding of these challenges and the potential solutions. This study presents, in part, a roadmap from the current cellular technologies toward fully MTC-capable 5G mobile systems.Peer reviewe

Redox functional groups of humic substances.

A new analytical technique based on palladium (Pd) and H2 catalytic system showed significant potential as a useful method for reliably assessing redox sites in humic substances. The technique identifies redox sites as a function of their resistance to the hydrogenolysis process. The test system consists of catalytic reduction process, the measurement of electron carrying capacity, and air oxidation. The extent of hydrogenolysis, which occurs during the catalytic reduction, can be controlled by pH and the type of catalyst used in the system. Verification of the reversibility of the redox sites is also permitted due to the use of a removable catalyst that allows the test to be repeated. Eight quinone compounds and fourteen humic substance samples were examined using this technique. The tests with quinone compounds demonstrated that hydrogenolysis occurring in the pH 6.5-Pd/Al2O3 redox system effectively removed quinone moieties in all model compounds. When the system's pH was increased to 8, the extent of hydrogenolysis became less intense. Quinones with an electron withdrawing substituent were left intact. As hydrogenolysis was further compromised by removing Al2O3 from the system, quinones without substituents and quinones with adjacent electron donating functional groups also remained intact. At that point, only quinones with an electron donating substituent located far away in a separate conjugated system suffered hydrogenolysis. The humic substance samples' tests showed that six landfill leachate humic substances, which were highly aliphatic, did not have redox sites. Eight other humic substance samples were capable of shuttling electrons, even in the pH 6.5-Pd/Al2O3 redox system, which had removed their quinone redox sites. The technique showed that redox sites in humic substance samples include both nonquinone (NQ) and quinone groups. Redox sites in the NQ group were responsible for 21%--56% of the electron carrying capacity (ECC) of the samples. The technique divided redox sites in the quinone group into two subgroups. The first subgroup includes redox sites with a neighboring electron withdrawing substituent which was liable for 13%--58% of the ECC. The second subgroup contains redox sites characterized by having an adjacent electron donating substituent and were accountable for 8%--50% of ECC

Determinants of English Language Proficiency: A Multifaceted Analysis

This study investigates the determinants of English language proficiency among students at Panyapiwat Institute of Management (PIM) in accordance with the Common European Framework of Reference for Languages (CEFR) standards. The determinant factors under examination encompass students' attitudes, prior English language knowledge, information-seeking behavior, satisfaction with English language learning, teachers' expertise, teacher readiness, teaching methodologies, familial support, environmental factors, and international exposure. Data were gathered through a survey administered to 469 PIM students, and the analysis employed Partial Least Squares Structural Equation Modelling. The findings revealed that five significant factors influence PIM students' English proficiency, namely their prior English language knowledge, inclination toward seeking knowledge, teachers' expertise, classroom environment, and practical language usage experiences. Additionally, the research demonstrated a noteworthy impact of students' Grade Point Average (GPA) and the time dedicated to learning English on their CEFR scores. This study contributes to the field by shedding light on the multifaceted factors influencing English language proficiency among PIM students, offering insights that can inform language education strategies and policies. It emphasizes the importance of prior knowledge, information-seeking behavior, teacher quality, classroom environment, and practical language application in enhancing English language skills. Doi: 10.28991/ESJ-2023-SIED2-020 Full Text: PD

Implementing opportunistic spectrum access in LTE-Advanced

Long term evolution advanced (LTE-A) has emerged as a promising mobile broadband access technology aiming to cope with the increasing traffic demand in wireless networks. However, the enhanced spectral efficiency offered by LTE-A may become futile without a better management of scarce and overcrowded electromagnetic spectrum. In this sense, cognitive radio (CR) has been proposed as a potential solution to the problem of spectrum scarcity. Among all the mechanisms provided by CR, opportunistic spectrum access (OSA) aims at a dynamic and seamless use of certain licensed bands provided the licensee is not harmfully affected. This operation requires spectral awareness in order to avoid interferences with licensed systems. In spite of implementing some spectrum sensing mechanisms, LTE-A technology lacks other tools that are needed in order to improve the knowledge of the radio environment. This work studies the adoption of a Geo-located data base (Geo-DB) that cooperatively retrieves and maintains information regarding the location of unutilized portions of spectrum potentially available for OSA. Moreover, the potential benefit of this LTE-compliant OSA solution is evaluated using a calibrated simulation tool, by which numerical results allow us to optimally configure the system and show that the proposed opportunistic system is able to significantly improve its performance.The authors would like to thank the funding received from the Ministerio de Ciencia e Innovacion within the Project number TEC2011-27723-C02-02 and from the Ministerio de Industria, Turismo y Comercio TSI-020100-2011-266 funds. This article had been written in the framework of the CELTIC project CP08-001 COMMUNE. Study by X. Gelabert is funded by the BP-DGR 2010 scholarship (ref. 00192). The authors would like to acknowledge the contributions of their colleagues.Osa Ginés, V.; Herranz Claveras, C.; Monserrat Del Río, JF.; Gelabert, X. (2012). Implementing opportunistic spectrum access in LTE-Advanced. EURASIP Journal on Wireless Communications and Networking. 2012(99):1-17. https://doi.org/10.1186/1687-1499-2012-99S117201299Martín-Sacristán D, Monserrat JF, Cabrejas-Peñuelas J, Calabuig D, Garrigas S, Cardona N: On the way towards fourth-generation mobile: 3GPP LTE and LTE-Advanced. EURASIP J Wirel Commun Netw 2009, 2009: 1-10.Ratasuk R, Tolli D, Ghosh A: Carrier aggregation in LTE-Advanced. In IEEE 71st Vehicular Technology Conference (VTC 2010-Spring). Taipei; 2010:1-5.Wang H, Rosa C, Pedersen K: Performance of uplink carrier aggregation in LTE-advanced systems. In IEEE 72nd Vehicular Technology Conference Fall (VTC 2010-Fall). Ottawa; 2010:1-5.Tandra R, Sahai A, Mishra S: What is a spectrum hole and what does it take to recognize one? 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In International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT). Moscow; 2010:965-969.Hussain S, Fernando X: Spectrum sensing in cognitive radio networks: Up-to-date techniques and future challenges. In IEEE Toronto International Conference on Science and Technology for Humanity (TIC-STH). Toronto; 2009:736-741.Xu Y, Sun Y, Li Y, Zhao Y, Zou H: Joint sensing period and transmission time optimization for energy-constrained cognitive radios. EURASIP J Wirel Commun Netw 2010, 2010: 1-16.Yucek T, Arslan H: A survey of spectrum sensing algorithms for cognitive radio applications. IEEE Commun Surv Tutor 2009, 11: 116-130.Cabric D, Mishra S, Brodersen R: Implementation issues in spectrum sensing for cognitive radios. In Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers. Volume 1. Pacific Grove; 2004:772-776.Zeng Y, Liang YC, Hoang A, Peh E: Reliability of spectrum sensing under noise and interference uncertainty. In IEEE International Conference on Communications Workshops, 2009. ICC Workshops. Dresden; 2009:1-5.Bixio L, Ottonello M, Raffetto M, Regazzoni CS: Comparison among cognitive radio architectures for spectrum sensing. EURASIP J Wirel Commun Netw 2011, 2011: 1-18.Mustonen M, Matinmikko M, Mammela A: Cooperative spectrum sensing using quantized soft decision combining. In 4th International Conference on Cognitive Radio Oriented Wireless Networks and Communications, 2009 (CROWNCOM'09). Hannover; 2009:1-5.Xiao L, Liu K, Ma L: A weighted cooperative spectrum sensing in cognitive radio networks. In International Conference on Information Networking and Automation (ICINA). Volume 2. Kunming; 2010:45-48.Pan Q, Chang Y, Zheng R, Zhang X, Wang Y, Yang D: Solution of information exchange for cooperative sensing in cognitive radios. In IEEE Wireless Communications and Networking Conference, 2009 (WCNC'2009). Budapest; 2009:1-4.Masri A, Chiasserini CF, Perotti A: Control information exchange through UWB in cognitive radio networks. In 5th IEEE International Symposium on Wireless Pervasive Computing (ISWPC). Modena; 2010:110-115.Celebi H, Arslan H: Utilization of location information in cognitive wireless networks. IEEE Wirel Commun 2007, 14(4):6-13.FCC: Notice of Proposed Rulemaking, in the Matter of Unlicensed Operation in the TV Broadcast Bands (ET Docket no. 04-186) and Additional Spectrum for Unlicensed.Marcus MJ, Kolodzy P, Lippman A: Reclaiming the vast wasteland: why unlicensed use of the white space in the TV bands will not cause interference to DTV viewers. New America Foundation: wireless future program, tech rep 2005.Nam H, Ghorbel M, Alouini M: Proc. of the Fifth International Conference on Cognitive Radio Oriented. In Proc of the Fifth International Conference on Cognitive Radio Oriented Wireless Networks Communications (CROWNCOM). Cannes; 2010:1-5.IEEE Std 80221-2008: IEEE Standard for Local and Metropolitan Area Networks-Part 21: Media Independent Handover. 2009.3GPP TS 36133: Evolved Universal Terrestrial Radio Access (E-UTRA); Requirements for support of radio resource management.Sesia S, Baker M, Toufik I: LTE, the UMTS long term evolution: from theory to practice. Wiley, New Haven; 2009.Digham FF, Alouini MS, Simon MK: On the energy detection of unknown signals over fading channels. In IEEE International Conference on Communications, 2003 (ICC'03). Volume 5. Anchorage; 2003:3575-3579.Ghasemi A, Sousa ES: Collaborative spectrum sensing for opportunistic access in fading environments. In First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN). Baltimore; 2005:131-136.Gelabert X, Akyildiz IF, Sallent O, Agustí R: Operating point selection for primary and secondary users in cognitive radio networks. Comput Netw 2009, 53(8):1158-1170. 10.1016/j.comnet.2009.02.009Taniuchi K, Ohba Y, Fajardo V, Das S, Tauil M, Cheng YH, Dutta A, Baker D, Yajnik M, Famolari D: IEEE 802.21: media independent handover: features, applicability, and realization. IEEE Commun Mag 2009, 47: 112-120.3GPP TS 36305: Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Stage 2 functional specification of User Equipment (UE) positioning in E-UTRAN.3GPP TS 36355: Evolved Universal Terrestrial Radio Access; LTE Positioning Protocol (LPP).3GPP TS 36455: Evolved Universal Terrestrial Radio Access; LTE Positioning Protocol A (LPPa).Ren W, Zhao Q, Swami A: Power control in cognitive radio networks: how to cross a multi-lane highway. IEEE J Sel Areas Commun 2008, 27(7):1283-1296.3GPP R1-084424: Control Channel Design Issues for Carrier Aggregation in LTE-A.Dajie J, Haiming W, Malkamaki E, Tuomaala E: Principle and performance of semi-persistent scheduling for VoIP in LTE system. In International Conference on Wireless Communications, Networking and Mobile Computing, 2007 (WiCom 2007). Shanghai; 2007:2861-2864.Rajbanshi R, Wyglinski AM, Minden GJ: An efficient implementation of NC-OFDM transceivers for cognitive radios. In Proc of 1st Conf on Cognitive Radio Oriented Wireless Networks and Commun. Mykonos; 2006:1-5.Wellens M, Riihijarvi J, Mahonen P: Modeling primary system activity in dynamic spectrum access networks by aggregated ON/OFF-processes. In 6th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks Workshops, 2009. SECON Workshops'09. Rome; 2009:1-6.3GPP TS 36214: Physical layer; Measurements.Ofuji Y, Morimoto A, Abeta S, Sawahashi M: Comparison of packet scheduling algorithms focusing on user throughput in high speed downlink packet access. In 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications. Volume 3. Lis-boa; 2002:1462-1466.ITU-R ITU M2135: Guidelines for evaluation of radio interface technologies for IMT-Advanced 2008

The contribution of cultural intelligence to team processes and innovation in multicultural teams : the case of restaurant business in Thailand

Thesis (Ph.D. (Management))--National Institute of Development Administration, 2019In many big cities characterized by multicultural environments which are also major tourist destinations of Thailand, many restaurants hire multicultural teams to help them achieve successful innovation. Even though cultural diversity among team members can potentially foster the innovative performance of multicultural teams, it can also cause challenges that would inhibit them from successful innovation. In particular, cultural diversity existing in teams can create unpleasant relationships and tension among team members, thereby limiting team synergy, which is a key factor in achieving team innovations. Given that cross-cultural diversity in a team could be productive and counterproductive to team performance, it is crucial to understand some characteristics of members in cross-cultural teams that might motivate them to overcome negative perceptions caused by cultural dissimilarity, and to work together effectively to produce an innovative performance for a restaurant. Among key characteristics that are crucial to enhance cross-cultural collaboration and performance, cultural intelligence (CQ) is frequently proposed in research as a crucial competency that makes members from diverse cultural backgrounds develop healthy relationships with each other thereby facilitating effective cross-cultural interaction and collaboration. Despite this crucial role of CQ, no research investigated the contribution of CQ to team innovation in the restaurant business. Therefore, this research investigated the contributions of team CQ to team innovation by considering the mediating roles of relationship conflict, intra-team trust, and team knowledge-sharing in the context of multicultural teams in the restaurant business. Survey data were collected from 103 cross-cultural teams (a total of 620 team members from diverse cultural backgrounds) of restaurants located in five popular tourist cities in Thailand, including Bangkok, Pattaya, Chiang Mai, Krabi, and Phuket. Data were collected from multiple sources to prevent common method bias. The data that measured team CQ, team relationship conflict, intra-team trust, and team knowledge-sharing were collected from all members in each team and were averaged to create the aggregate measures at the team-level. Team innovative performance was evaluated by the team supervisor. Partial least squares structural equation modeling was used for data analysis.  The results indicated that the teams demonstrating high CQ tended to exhibit a lower degree of team relationship conflict and the higher degree to intra-team trust, and team knowledge-sharing, and received a higher degree of innovative performance evaluation than the team demonstrating low CQ. The results also showed that team conflict and team knowledge-sharing mediated the relationship between team CQ and team innovation.  Besides, intra-team trust can indirectly connect team CQ to team innovation by either reducing team conflict or increasing team knowledge sharing, as well as team relationship conflict that can also indirectly help team CQ to increase team innovation that a lower degree of team relationship conflict driven by a higher degree of team CQ can increase team knowledge-sharing that eventually foster team innovation. The contribution of CQ in the cross-cultural team using team-level CQ provided additional evidence to prior CQ research that rarely investigated CQ at the aggregate level, especially the contribution of CQ at the team level to innovation in intercultural teams as well as the mechanism between them focusing on the roles of relationship conflict, intra-team trust, and knowledge sharing. Moreover, this research also provided insight and a guideline for restaurant management and human resource teams to promote the innovative performance of their multicultural teams. The research suggested that CQ should be integrated into the process of talent discovering and acquisition, performance management and reward systems, and human resource management routines. This could enable organizations to develop and retain the global talents needed in maintaining their competitive advantages in today’s business environment.  

The Impact of the No-Plastic-Bag Campaign on Customer Repurchase Intentions and its mechanism in the Modern Trade Business in Bangkok

This research investigated the impact of the no-plastic-bag campaign on customer repurchase intentions in the modern trade business in Bangkok. Six hundred customers of modern trade stores in Bangkok were initially approached using a stratified random sampling method, but only 418 of them participated in this survey. The partial least squares structural equation results indicated that the no-plastic-bag campaign promotes customer repurchase intentions (β=0.098; p=0.038). Also, the no-plastic-bag campaign could indirectly foster customer repurchase intentions via both enhancing brand image (t=7.379; p&lt;0.001) and increasing customers’ perceived value (t=2.806; p&lt;0.001). Therefore, it can be concluded that the no-plastic-bag campaign benefits modern trade businesses, promoting customer repurchase intentions by enhancing their brand image and customer perceived values. This research also explored the mediating roles of brand image and perceived value on the relationship. These findings provide new knowledge of the no plastic bag campaign’s contribution to customer repurchase intentions which has not yet been investigated, and the mechanism linking them together. The results can be applied as a guideline to other modern-trade businesses or other businesses to enhance their brand image and promote customer repurchase intentions, which is crucial to sustainable business accomplishment.&#x0D; This research investigated the impact of the no-plastic-bag campaign on customer repurchase intentions in the modern trade business in Bangkok. Six hundred customers of modern trade stores in Bangkok were initially approached using a stratified random sampling method, but only 418 of them participated in this survey. The partial least squares structural equation results indicated that the no-plastic-bag campaign promotes customer repurchase intentions (β=0.098; p=0.038). Also, the no-plastic-bag campaign could indirectly foster customer repurchase intentions via both enhancing brand image (t=7.379; p&lt;0.001) and increasing customers’ perceived value (t=2.806; p&lt;0.001). Therefore, it can be concluded that the no-plastic-bag campaign benefits modern trade businesses, promoting customer repurchase intentions by enhancing their brand image and customer perceived values. This research also explored the mediating roles of brand image and perceived value on the relationship. These findings provide new knowledge of the no plastic bag campaign’s contribution to customer repurchase intentions which has not yet been investigated, and the mechanism linking them together. The results can be applied as a guideline to other modern-trade businesses or other businesses to enhance their brand image and promote customer repurchase intentions, which is crucial to sustainable business accomplishment.</jats:p

Designing IMSA\u27s Al Future: Al Center Curricular Connections Intern

The Al Center\u27s goal is to further development of Al curriculum, opportunities, and development within the Illinois Mathematics and Science Academy (IMSA). My role in the Al Center included the creation and management of the Al Center Student Innovation Cohort, which is a small team of students which research and create lessons on Al related topics to implement in upcoming classes such as Artificial Intelligence 1. While we primarily focuse on managing the team in order to provide quality results, we also contributed to the development of said curriculum through creating lesson plans. We also incorporated elements such as the LEGO Spike prime into activities within the lessons in order to assist with the visualization of certain Al related topics, leading to a more comprehensive and easy to understand lesson. Our end goal is the creation of content which would be not only used within IMSA, but also be readily available digitally in order to facilitate learning in Other educational organizations, leading to a general increase in knowledge in the field of Al