• Journal of Information Technology Services
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• v.15 no.1
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• pp.81-96
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• 2016

This study analyzes how breach fee under long-term contract and/or cap regulation on the breach fee can affect the impacts of "Mobile Device Distribution Improvement Act" on handset bundle price, average revenue per unit (ARPU), and social welfare. We conduct comparative analysis with an economic model of duopoly competition in price when users are under long-term contract and the breach fee can be regulated. The results show that the Act lowers the equilibrium prices, lower than incumbent price without the Act. Price of non-dominant Mobile Network Operator (MNO) can be lower than poaching price without the Act if significant portion of switching cost is breach fee or the market is significantly asymmetric. Under the significant circumstances, the Act can raise ARPU even though it improves social welfare. By contrast, the Act increases consumer surplus without affecting social welfare if breach fee is the only source of user's switching cost and is capped by the regulation, and more symmetric market and the stronger cap leads to higher consumer surplus.

• Journal of Power Electronics
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• v.17 no.1
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• pp.222-231
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• 2017

In this paper, a new architecture for a cost-effective power conditioning systems (PCS) using a single-sourced asymmetric cascaded H-bridge multilevel inverter (MLI) for photovoltaic (PV) applications is proposed. The asymmetric MLI topology has a reduced number of parts compared to the symmetrical type for the same number of voltage level. However, the modulation index threshold related to the drop in the number of levels of the inverter output is higher than that of the symmetrical MLI. This problem results in a modulation index limitation which is relatively higher than that of the symmetrical MLI. Hence, an extra voltage pre-regulator becomes a necessary component in the PCS under a wide operating bias variation. In addition to pre-stage voltage regulation for the constant MLI dc-links, another auxiliary pre-regulator should provide isolation and voltage balance among the multiple H-bridge cells in the asymmetrical MLI as well as the symmetrical ones. The proposed PCS uses a single-ended DC-DC converter topology with a coupled inductor and charge-pump circuit to satisfy all of the aforementioned requirements. Since the proposed integrated-type voltage pre-regulator circuit uses only a single MOSFET switch and a single magnetic component, the size and cost of the PCS is an optimal trade-off. In addition, the voltage balance between the separate H-bridge cells is automatically maintained by the number of turns in the coupled inductor transformer regardless of the duty cycle, which eliminates the need for an extra voltage regulator for the auxiliary H-bridge in MLIs. The voltage balance is also maintained under the discontinuous conduction mode (DCM). Thus, the PCS is also operational during light load conditions. The proposed architecture can apply the module-integrated converter (MIC) concept to perform distributed MPPT. The proposed architecture is analyzed and verified for a 7-level asymmetric MLI, using simulation results and a hardware implementation.

• Molecules and Cells
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• v.39 no.7
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• pp.524-529
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• 2016

Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.194-211
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• 1993

This paper proposes an optimal incentive scheme for environmental pollution and output control in oligopoly markets under asymmetric information situation where the regulator has no information about each firm's technology on output productions and pollution abatements. We compare two interesting optimal incentive schemes (one is static model previously proposed and the other is dynamic model suggested in this paper), analyze features of these schemes, and carefully discuss its relevances to other schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.724-727
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• 2003

유무선 대체 및 통합시대를 맞아 유무선간 균형있는 발전을 위해 유럽 둥 주요국가에서는 이동전화 시장에 MVNO, 이동전화 번호이동성, 재판매 제도 등을 도입하여 실행하고 있다. 이처럼 유무선간 비대칭 규제를 해소하기 위해서 상대적으로 규제가 약한 이동전화 시장에 유선에 적용되는 규제를 적용하는 것이 유무선간 대칭규제를 위한 방안이 될 수 있다. 따라서 본 고에서는 이러한 입장에서 이동전화 시장을 활성화시키기 위한 정책들을 살펴보고 이를 이미 실행하고 있는 외국의 사례를 통해 이들 정책의 도입효과 등을 살펴보고자 한다.

• Proceedings of the Technology Innovation Conference
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• 2006.02a
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• pp.248-263
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• 2006

The convergence in telecommunication and broadcasting is one of the most popular topics in these days. For example, the characteristic of IPTV -internet protocol television-is controversial in the extreme. In Korea the IPTV operators are mainly the telecommunication service operators. So it is natural that the IPTV services are categorized to the telecommunication services. But the Broadcasting service providers, especially the CATV providers who can serve the TPS-triple play service- like IPTV players insist that the IPTV should be regulated as a broadcasting service. This paper will analyze whether the regulation in which the IPTV is categorized to one of the broadcasting services is better than the case of telecommunication services. To examine this, the social welfare analysis is conduced and the differential oligopoly market model is used. Together with that, this paper suggests that we can improve the social welfare by the asymmetric regulation between IPTV and D-CA TV. This means that in Korea the IPTV has a weak substitution relation with the D-CA TV and the IPTV should be dealed as a new convergence service that differs from traditional broadcasting services.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.05a
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• pp.41-58
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• 2001

The growth of fixed telephony has been steady but unexceptional. The number of mobile telephone subscribers, however, has increased dramatically throughout the decade. The increasing prevalence of mobile communications, in conjunction with the relatively high penetration of fixed telephony, will cause the market for converged services to become significant in coming decade. The current fixed and mobile regulatory regimes are very different. Regulation of the fixed market tends to focus on monitoring the activities of incumbent operator and ensuring that other operators can compete on a fair basis. Mobile markets have historically been more competitive, and the asymmetric nature of regulation of these markets has not been as prevalent as for fixed communications. The purpose of this paper is to identify the fixed-mobile convergence and to suggest the future regulatory principles for fixed-mobile convergence.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2030-2038
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• 2009

We analyze the economic effects of mobile termination rate asymmetry by simulation model. The asymmetry allows the mobile operator to get access profits at the expense of the incumbent and induces negative effects such as the entry of inefficient operator and allocative efficiency as well as productive efficiency. We use simulation model to investigate the effect on social welfare of asymmetric regulation. If the brand loyalty is high, social welfare increase as the termination charge of entrant increases. The extension of the basic model shows that the degree of social welfare increase becomes higher as the brand loyalty increases when the cost of entrant is smaller than that of incumbent. But, the degree of social welfare decrease becomes lower as the substitution effects increase.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3015-3024
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• 2018

This study investigates the recent asymmetric effect of news on stock return volatility in Asian five stock markets - Japan, Korea, Singapore, Taiwan, and Malaysia - since 2000. This study uses the GJR-M model which shows a different effect of a good and bad news on volatility. Empirical results show that the unexpected negative return has a more crucial effect on stock return volatility than the unexpected positive one does in all five stock markets. This implies that the bad news of the stock markets gives a more remarkable effect on volatility than good news does. This study finds that it is very important for market participants and regulation practitioners to distinguish between positive and negative return shocks in the stock markets since bad news might have a larger impacts on volatility than good news.

• BMB Reports
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• v.51 no.11
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• pp.547-548
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• 2018

Phloem network integrates cellular energy status into post-embryonic growth, and development by tight regulation of carbon allocation. Phloem development involves complicated coordination of cell fate determination, cell division, and terminal differentiation into sieve elements (SEs), functional conduit. All of these processes must be tightly coordinated, for optimization of systemic connection between source supplies and sink demands throughout plant life cycle, that has substantial impact on crop productivity. Despite its pivotal role, surprisingly, regulatory mechanisms underlying phloem development have just begun to be explored, and we recently identified a novel translational regulatory network involving RNA G-quadruplex and a zinc-finger protein, JULGI, for phloem development. From this perspective, we further discuss the role of RNA G-quadruplex on post-transcriptional control of phloem regulators, as a potential interface integrating spatial information for asymmetric cell division, and phloem development.