Competition between B-Z and B-L transitions in a single DNA molecule: Computational studies

Under negative torsion, DNA adopts left-handed helical forms, such as Z-DNA and L-DNA. Using the random copolymer model developed for a wormlike chain, we represent a single DNA molecule with structural heterogeneity as a helical chain consisting of monomers which can be characterized by different helical senses and pitches. By Monte Carlo simulation, where we take into account bending and twist fluctuations explicitly, we study sequence dependence of B-Z transitions under torsional stress and tension focusing on the interaction with B-L transitions. We consider core sequences, (GC)(n) repeats or (TG)(n) repeats, which can interconvert between the right-handed B form and the left-handed Z form, imbedded in a random sequence, which can convert to left-handed L form with different (tension dependent) helical pitch. We show that Z-DNA formation from the (GC)(n) sequence is always supported by unwinding torsional stress but Z-DNA formation from the (TG)(n) sequence, which are more costly to convert but numerous, can be strongly influenced by the quenched disorder in the surrounding random sequence.National Research Foundation NRF-2012 R1A1A3013044 NRF-2014R1A1A2055681NRF-2012R1A1A2021736IBS-R023-D1NRF-2015R1A2A2A01005916Chemistr

Analysis of the barriers that consumers encounter when smart home service is introduced in South Korea

Recently, smart home services have been highlighted as the Internet of things market grows. Since the smart home services were introduced in the market, they were expected to grow rapidly. However, the smart home market recently experienced chasm, and still remains in early stage. This paper tried to find the possible barriers that consumers encounter when they are faced with smart home services. Based on the resistance theory and perceived risk model, this paper investigates the influence of perceived risk on the resistance using the technological uncertainty and service intangibility as the antecedents of the perceived risk. Dividing the perceived risks into four types of performance risk, financial risk, privacy risk and psychological risk, the empirical results show that these four types of risk are affected by the technological uncertainty and service intangibility on the one hand, and have positive effects on the resistance to smart home on the other hand. When the survey respondents are divided into two groups of postponers and rejecters based on the resistance type, there are no big differences except that the privacy risk becomes unimportant to postpners and the financial risk becomes unimportant to rejecters

Estimating the potential increase in consumer welfare from the introduction of 'Super Wi-Fi' service

With the increasing use of smart devices recently, mobile traffic has been increasing rapidly, which in turn results in greater demand for the frequency. Many countries have attempted to use the vacant frequencies known as TV White Space (TVWS) in an effort to solve the frequency problem. Super Wi-Fi service, a wireless Internet service based on TVWS, is one of the ways TVWS is being utilized. This paper applies conjoint analysis to evaluate consumers’ willingness to pay for each of the attributes of Super Wi-Fi service and estimates how much consumer welfare could be improve by the introduction of Super Wi-Fi service. The attributes of Super Wi-Fi service are coverage, a reduction in communication expenses when using mobile data, the ability to use multiple-screens, and a wide range of Wi-Fi service providers. The results based on user surveys indicated that the marginal willingness to pay (MWTP) amount per month for Super Wi-Fi service is KRW 4,717 (USD 4.6). Moreover, the MWTP amount in non-urban areas for this service is greater than that in urban areas, implying that the introduction of Super Wi-Fi service is expected to increase consumer welfare, especially in non-urban areas