Sources of gravity waves in the polar middle atmosphere

Gravity waves are considered to be important for dynamics and chemistry in the polar middle atmosphere. However, there are only a limited number of studies of gravity waves in the polar region mostly because of difficulty of their observation. One of the significant issues on gravity waves is their source, because wave parameters such as wavelengths and phase velocities which are essential to evaluate the gravity wave effects on the large-scale field are highly dependent on the source. This paper describes dominant sources of gravity waves in the polar regions, namely topography, the polar- night jet, and tropical convection, by reviewing results from recent studies

Coping measurement and the state effect of depression and anxiety in psychiatric outpatients

The relationship between coping styles and mental health has received considerable attention, but the state effects on coping measures in a clinical sample are not well known. This study investigated changes in scores on the Coping Inventory for Stressful Situations between two treatment phases (acute and remitted phase) in 49 outpatients with major depression or anxiety disorders. Task-oriented coping changed significantly between the treatment phases in both depressive and anxious patients, as analyzed by two-way multivariate analysis of variance. Results from repeated measures of multivariate analysis of covariance indicated that task-oriented coping was influenced by depression and emotion-oriented coping was influenced by anxiety. Avoidance-oriented coping did not change significantly over time in either depressive or anxiety disorders controlled for depressive and anxiety symptoms. The results of this study suggest that depressive or anxiety symptoms and treatment phase affect coping measurement. Copyright (C) 2002 S. Karger AG, Basel

Design of the NIPR trajectory model

Kinematic and isentropic trajectory models developed at the National Institute of Polar Research(NIPR) are compared with METEX developed at the Center for Global Environmental Research, National Institute for Environmental Studies(CGER/NIES). The NIPR model shows good agreement with METEX both in the kinematic and isentropic trajectories. An intercomparison between the tra-jectories computed with different datasets is also performed using the NIPR model, and shows that the accuracy of the trajectory is far more sensitive to the difference of the dataset used than to the difference of trajectory model

Distributed Interference-Aware Energy-Efficient Resource Allocation for Device-to-Device Communications Underlaying Cellular Networks

The introduction of device-to-device (D2D) into cellular networks poses many new challenges in the resource allocation design due to the co-channel interference caused by spectrum reuse and limited battery life of user equipments (UEs). In this paper, we propose a distributed interference-aware energy-efficient resource allocation algorithm to maximize each UE's energy efficiency (EE) subject to its specific quality of service (QoS) and maximum transmission power constraints. We model the resource allocation problem as a noncooperative game, in which each player is self-interested and wants to maximize its own EE. The formulated EE maximization problem is a non-convex problem and is transformed into a convex optimization problem by exploiting the properties of the nonlinear fractional programming. An iterative optimization algorithm is proposed and verified through computer simulations.Comment: 6 pages, 3 figures, IEEE GLOBECOM 201

Energy Efficiency and Spectral Efficiency Tradeoff in Device-to-Device (D2D) Communications

In this letter, we investigate the tradeoff between energy efficiency (EE) and spectral efficiency (SE) in device-to-device (D2D) communications underlaying cellular networks with uplink channel reuse. The resource allocation problem is modeled as a noncooperative game, in which each user equipment (UE) is self-interested and wants to maximize its own EE. Given the SE requirement and maximum transmission power constraints, a distributed energy-efficient resource allocation algorithm is proposed by exploiting the properties of the nonlinear fractional programming. The relationships between the EE and SE tradeoff of the proposed algorithm and system parameters are analyzed and verified through computer simulations.Comment: 8 pages, 6 figures, long version paper of IEEE Wireless Communications Letters, accepted for publication. arXiv admin note: text overlap with arXiv:1405.196

Interhemispheric Coupling Study by Observations and Modelling (ICSOM)

第6回極域科学シンポジウム分野横断型セッション：[IM] 横断　中層大気・熱圏11月17日（火）　統計数理研究所 セミナー室2（D304

TEM analysis and comparison on the BDC using several reanalysis data sets

第3回極域科学シンポジウム　横断セッション「中層大気・熱圏」 11月26日（月） 国立極地研究所 ２階大会議

A Game-Theoretic Approach to Energy-Efficient Resource Allocation in Device-to-Device Underlay Communications

Despite the numerous benefits brought by Device-to-Device (D2D) communications, the introduction of D2D into cellular networks poses many new challenges in the resource allocation design due to the co-channel interference caused by spectrum reuse and limited battery life of User Equipments (UEs). Most of the previous studies mainly focus on how to maximize the Spectral Efficiency (SE) and ignore the energy consumption of UEs. In this paper, we study how to maximize each UE's Energy Efficiency (EE) in an interference-limited environment subject to its specific Quality of Service (QoS) and maximum transmission power constraints. We model the resource allocation problem as a noncooperative game, in which each player is self-interested and wants to maximize its own EE. A distributed interference-aware energy-efficient resource allocation algorithm is proposed by exploiting the properties of the nonlinear fractional programming. We prove that the optimum solution obtained by the proposed algorithm is the Nash equilibrium of the noncooperative game. We also analyze the tradeoff between EE and SE and derive closed-form expressions for EE and SE gaps.Comment: submitted to IET Communications. arXiv admin note: substantial text overlap with arXiv:1405.1963, arXiv:1407.155

A diagnostic study of waves on the tropopause

The spatial structure and phase velocity of tropopause disturbances localized around the subpolar jet in the Southern Hemisphere are investigated using 6-hourly European Centre for Medium-Range Weather Forecasts reanalysis data covering 15 yr (1979–93). The phase velocity and phase structure of the tropopause disturbances are in good agreement with those of an edge wave vertically trapped at the tropopause. However, the vertical distribution of the ratio of potential to kinetic energy exhibits maxima above and below the tropopause and a minimum around the tropopause, in contradiction to edge wave theory for which the ratio is unity throughout the troposphere and stratosphere. This difference in vertical structure between the observed tropopause disturbances and edge wave theory is attributed to the effects of a finite-depth tropopause together with the next-order corrections in Rossby number to quasigeostrophic dynamic