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Motivational research has become one of the major topics in public administration. However, public administration researchers have focused disproportionately on public service motivation in accounting for behaviors/attitudes in the public sphere. Somewhat neglected are the different, but no less important, motivations that impact the everyday operations of government employees. To narrow the gap, this study examines the effect of motivations based on organizational mission (mission match) and perceived organizational reputation. Using a large- N sample of U.S. federal employees, results show that mission-matched employees are more likely to be satisfied with their organization. This relationship is mediated through perceived organizational reputation. This study discuss the contributions of introducing organizational reputation as a contextual factor that intervenes in bureaucratic motivation and raise questions for further inquiry.

While legitimacy plays a key role in determining if a public sector rule or process objectively qualifies as red tape, it is unclear if legitimacy shapes subjective red tape judgments. We use a sample of South Korean citizens and a vignette-based survey experiment describing applying for a small business COVID-19 relief fund to test the relevance of rule legitimacy for perceived red tape. We find that obtaining a favorable outcome (receiving the fund) reduces perceived red tape, but that neither input nor output legitimacy plays a consistent role. Second, we find that public service motivation moderates the role of both input and output legitimacy on perceived red tape, though in different directions. For those with high levels of public service motivation, output legitimacy reduces perceived red tape. However, for the same group, input legitimacy increases it. We provide a detailed discussion of the contributions of our study.

This article examines government employees’ experience and expectation of socioeconomic hardships during the COVID-19 pandemic—employment income loss, housing instability, and food insufficiency—by focusing on the role of gender and race. Employing the Household Pulse Survey, a nationally representative and near real-time pandemic data deployed by the U.S. Census Bureau, we find that government employees were less affected by the pandemic than non-government employees across socioeconomic hardships. However, female and racial minorities, when investigated within government employees, have a worse experience and expectation of pandemic hardships than men and non-Hispanic Whites. Our findings suggest a clear gender gap and racial disparities in the experience and expectation of pandemic hardships.

Previous studies highlight the role of walkable neighborhoods in improving the health status of residents, hypothesizing that there is a strong relationship between the built environment and individual physical activity. However, unlike theoretical prediction, the evidence is less established that residents in inner cities engage in more physical activity than residents in suburban areas. To address this gap between theoretical prediction and empirical evidence in physical activity studies, this paper investigates the links between the built environment and outdoor leisure activities under the individual time constraint. We conducted path analysis, employing the samples of Los Angeles County in NHTS (National Household Travel Survey, 2008–2009). Empirical results revealed that individual time constraints have a significant negative effect on leisure time spent in outdoors, but the influence was marginal. Surprisingly, the access to local resource (e.g., park area) still matters even after time constraints are controlled for. Regarding the effects of other covariates, safety (perceived), attitude, and disability showed the largest association with outdoor leisure activities amongst the independent variables with the expected sign. Based on these results, this study not only confirms that the lack of time plays a role as a barrier of the outdoor leisure activity, but also proves that park area can be considered as a facilitator. However, the behavioral decision for outdoor leisure activities is about more than time constraints and the built environment since the effects of both are much smaller than other key covariates.

Although the causes of asthma are inconclusive, it is fairly known that exposure to outdoor air pollutants can cause asthma, especially children's asthma morbidity. Whereas transportation is one of the major sectors that generate air pollutants, previous research that investigates the correlation between transportation and asthma narrowly focuses on the contribution of automobile traffic to children's asthma. Developing three spatial regression models (a spatial lag (SL) model, a spatial error (SE) model, and a general spatial (SAC) model), this paper investigates the roles of a variety of transportation factors in two distinct stages of children's asthma morbidity; asthma and severe asthma. With consideration to asthma-related socio-economic factors in the City of Seoul, the SE (R2 = 0.31) and SAC (R2 = 0.34) models consistently indicate that three out of four transportation factors associate with children's severe asthma at statistically significant level. They include the negative influence of bus transit and dense intersections, and the positive influence of active transportation activities on children's asthma severity. Interestingly, however, no significant contribution of transportation factors to children's asthma morbidity was identified by the SE (R2 = 0.29) and SAC (R2 = 0.28) models. Shedding more light on the complexity of children's asthma morbidity and severity, this paper proposes collaborative partnerships not only among multi- dimensional agencies, but also among multi-level government organizations.

This paper aims to investigate the role of neighborhood tree and greenspace on asthma morbidity, especially asthma emergency room visits. We employed advanced spatial data which allow for precisely capturing both the quantity and the features of tree and greenspace within a neighborhood environment. The results from the spatial regression models in Los Angeles County revealed that the features of trees and greenspace, such as the configuration of the tree canopy, the level of tree clustering, and private neighborhood greenspaces contribute to decreasing asthma morbidity, in addition to the quantity of tree and greenspace acreages. Notably, however, large scale greenspace, such as golf courses, school playgrounds, and parks fails to reduce the number of asthma emergency room visits at the statistically significant level. These findings imply that the creation of dense or clustered tree patches and small-scale neighborhood greenspaces might play a substantial role in mitigating air quality and consequently reducing asthma emergency room visits.

Extensive literature examines the relation between land use patterns and obesity, but less work explores whether local employment centers may reduce obesity. Local employment centers may affect obesity via providing agglomeration benefits such as increased job/transportation opportunities and closer proximity to local facilities/destinations. We utilized a large serial cross-sectional health survey from Los Angeles, California, conducted over three periods, to examine whether the presence of local employment centers modifies the association between land use patterns and individual body mass index. We retrieved individual health and sociodemographic data from the Los Angeles County Health Survey (2002, 2005, and 2007). To this Health Survey, we linked land use attributes at the census tract level collected from the Southern California Association of Governments. Our log-transformed regression models present interactions between local employment centers, neighborhood urban form features, and body mass index. Although most findings are consistent with previous studies, some of land use factors hypothesized to reduce the risk of obesity could have counterintuitive associations unless local employment centers were controlled. The unexpected results of our land use coefficients indicate that the tenet of New Urbanism may not necessarily promote health benefits. Our findings suggest that modifying the built environment may be effective in reducing obesity only in areas with high degree of local employment centers. Future studies would benefit from longitudinal and experimental, rather than cross-sectional, study designs that rigorously test the potential causal role of New Urbanism on obesity.

This paper aims to examine various built environment factors contributing to asthma and severe asthma morbidities in older people by performing spatial regression analysis. By controlling the socio-demographic factors of asthma in Seoul, we found a significant correlation of the built environment factors with severe asthma rather than with asthma in older people. The results suggest that population density and bus transit can make asthma severe in older people, while active transportation activities have a positive influence on severe asthma in older people. However, a significant contribution of built environment factors to asthma in older people is not identified. The findings from spatial regression imply that the collaboration of multi-level governments and agencies needs to develop policies for mitigating poor air quality from the perspective of environmental justice.

We propose a hybrid precoding scheme for downlink multi-user multiple-input multiple-output (MU-MIMO) millimeter-wave (mmWave) systems. Firstly, the proposed precoder is designed by the beam steering condition and the zero-interference condition, which can be obtained with the information of angles of departure (AoDs) in frequency division duplex (FDD) systems. Then, the proposed precoder is decomposed into the radio frequency (RF) precoder and the baseband precoder without the loss of response. Also, array response vector selection algorithm is proposed to prevent the sum rate degradation in numerous users region. Simulation results show that the sum rate of the proposed hybrid precoder is higher than those of the block diagonalization (BD) based schemes in the region of more than 5 users and approaches the sum rate of the beam steering scheme without MU interference as the number of base station (BS) antennas increases.

We design a spatial modulation (SM) scheme for spatially correlated channels under the constraints of a single radio frequency chain transmitter and open-loop transmission. To alleviate the performance degradation of the conventional SM in highly correlated channels, the proposed SM scheme adopts the antenna grouping and a new space-phase constellation, which is designed by considering the phase-only constraint and received symbol distance in fully correlated channels. In the simulation results, the proposed scheme achieves about 2.5-dB gain at bit error rate of $10^{-3}$ compared with the conventional SM in highly correlated channels.

Points of interest (POIs)&mdash, areas with a concentration of places that attract people&mdash, are important urban planning and tourism policy targets. This study aims to determine the points of interest of urban residents by analyzing big data from search engines to reveal the physical characteristics of POIs. To achieve this, POI data were collected in three city centers in Seoul using a South Korean dominant portal site that includes a search engine. The most popular POIs were determined by using GIS search engine analysis frequency, and correlation and regression analyses were conducted to investigate the relation between POIs and urban elements. The results revealed different POI trends in each city center. While POIs were concentrated in old, narrow streets with small attractions and mixed-use construction near Seoul City Wall (historic downtown district), they also formed around notable architectural landmarks in the newly developed Yeouido and Yeongdeungpo areas. This study found that tourism attraction took different forms in old and new areas, demonstrating that citizens are interested in both historic downtown areas and new areas, as traditional urban theorists suggest. Thus, urban planners and tourism policy makers should consider specific spatial contexts with search engines.

We prepared poly(vinylidene fluoride) (PVDF)/multiwalled carbon nanotube (MWCNT) nanocomposites using the electrospinning process and investigated the effects of varying the MWCNT content, as well as the additional use of drawing and poling on the polymorphic behavior and electroactive (piezoelectric) properties of the membranes obtained. Fourier transform infrared spectroscopy and wide-angle X-ray diffraction revealed that dramatic changes occurred in the β-phase crystal formation with the MWCNT loading. This was attributed to the nucleation effects of the MWCNTs as well as the intense stretching of the PVDF jets in the electrospinning process. The remanent polarization and piezoelectric response increased with the amount of MWCNTs and piezoelectric β-phase crystals. A further mechanical stretching and electric poling process induced not only highly oriented β-phase crystallites, but also very good ferroelectric and piezoelectric performances. In the drawn samples, the interfacial interaction between the...

The increasing demand for low-power and high-performance multimedia embedded systems has motivated the need for effective solutions to satisfy application bandwidth and latency requirements under a tight power budget. As technology scales, it is imperative that applications are optimized to take full advantage of the underlying resources and meet both power and performance requirements. We propose MultiMaKe, an application mapping design flow capable of discovering and enabling parallelism opportunities via code transformations, efficiently distributing the computational load across resources, and minimizing unnecessary data transfers. Our approach decomposes the application's tasks into smaller units of computations called kernels, which are distributed and pipelined across the different processing resources. We exploit the ideas of inter-kernel data reuse to minimize unnecessary data transfers between kernels, early execution edges to drive performance, and kernel pipelining to increase system throughput. Our experimental results on JPEG and JPEG2000 show up to 97% off-chip memory access reduction, and up to 80% execution time reduction over standard mapping and task-level pipelining approaches.

Memory and communication architecture have a significant impact on the performance, cost, and power of complex multiprocessor system-on-chip designs. In this paper, we present an automated bus matrix synthesis flow for efficient transaction-level design space exploration of communication architecture in a reconfigurable multimedia system-on-chip platform. Specifically, we consider hardware interface selection problem, which has significant effect on the overall cost of area and power. We propose a method to solve such hardware interface selection problem through static analysis of communication behavior. We experiment with JPEG encoder and H.264 encoder examples and the results show the reduction of area by 56.91% and power by 48.61% of bus matrix with 0.58% performance overhead on average compared to the case of maximum performance. According to our HW interface selection algorithm, we also experiment MPEG4 video decoder example. And the result is evaluated on the FPGA prototyping board.

Time-to-market pressure and the ever-growing design complexity of multiprocessor system-on-chips have demanded an efficient design environment that enables fast exploration of large design space. In this article, we introduce a new design environment, called SoCDAL, for accelerating multiprocessor system-on-chip design through fast design-space exploration targeting real-time multimedia systems. SoCDAL is a set of mostly automated tools covering system specification, hardware/software estimation, application-to-architecture mapping, simulation model generation, and system verification through simulation. For system specification, the process network model has been widely used for system specification because of its modeling capability. However, it is hard to use for real-time systems design, since its behavior cannot be estimated statically. We introduce a new approach which enables analyzing a process network model statically with some restrictions. For the hardware/software estimation, we analyze codes statically. Application-to-architecture mapping process implements a novel algorithm to support an arbitrary number of processors, with performance evaluation by static scheduling considering communication behavior. Mapping results are used to generate simulation models automatically at several transaction levels to be pipelined to a commercial tool. We show the effectiveness of our approaches by some experimental results with multimedia applications such as JPEG, H.263, and H.264 encoders, as well as an H.264 decoder.

We propose a filter-bank multicarrier (FBMC) system to transmit quadrature amplitude modulation (QAM), which can suppress sidelobe level of the odd prototype filter. We present low-pass filtering method obtaining frequency confinement property for the odd filter. Bit error rate (BER) performance shows that the proposed odd filter can enhance the FBMC system in multipath fading channels compared to the conventional QAM-FBMC system.

Given the concerns about urban mobility, traffic congestion, and greenhouse gas (GHG) emissions, extensive research has explored the relationship between the built environment and transit ridership. However, the nature of aggregation and the cross-sectional approach of the research rarely provide essential clues on the potential of a transit system as a sustainable mobility option. From the perspective of longitudinal sustainability, this paper develops regression models for rail transit stations in the Los Angeles Metro system. These models attempt to identify the socio-demographic characteristics and land use features influencing longitudinal transit ridership changes. Step-wise ordinary least square (OLS) regression models are used to identify factors that contribute to transit ridership changes. Those factors include the number of dwelling units, employment-oriented land uses such as office and commercial land uses, and land use balance. The models suggest a negative relationship between job and population balance with transit ridership change. They also raise a question regarding the 0.4 km radius commonly used in transit analysis. The models indicate that the 0.4 km radius is too small to capture the significant influence of the built environment on transit ridership.

As the demand for low power multimedia systems continues to grow, so will the need for low cost and efficient solutions. Driven by such need, as well as improvements IC design technology, Chip-Multiprocessors (CMPs) have emerged as a potential solution. CMPs offer flexibility, low cost, low power and the ability to handle highly parallel workloads. As CMPs scale, it is up to the designer to take full advantage of their computational resources and manage their constrained memory resources efficiently. In this paper we propose a methodology that enables designers to fully exploit the target platform's computational resources without sacrificing power consumption by maximizing the application's reuse. Our approach uses code transformations to split the application's tasks into smaller units of computations or subtasks called kernels. Each kernel is analyzed for inter and intra reuse opportunities in order to minimize unnecessary data transfers between kernels. Our approach also couples both scheduling/pipelining of tasks with their memory allocations. This allows us to obtain memory aware pipelined schedules that increases throughput and reduces power consumption. Our methodology has shown up to 15% performance improvements as well as 33% power reduction when compared to state of the art techniques.

In this paper, we propose system level dynamic power management of coarse-grained reconfigurable architectures through dynamic reconfiguration. The novelty of our approach is in two kinds of system level power management strategies for coarse-grained reconfigurable architectures considering the cost and quality-of-service (QoS) tradeoff by battery status. Experimental results on an MPEG4 video decoder show that our approach saves 17 percent energy when the system is in normal-battery mode and 36 percent energy when the system is in low-battery mode at the expense of some QoS degradation.

Power is one of the major constraints considered during the design of embedded software. In order to reduce power consumption without sacrificing performance, software needs to be optimized in order to run as efficiently as possible on a given platform. When attempting to optimize the mapping of a piece of software on a multiprocessor system, designers often face the chicken-and-egg problem of whether to schedule tasks first, or do memory allocation first, as either step will affect the different optimization opportunities the other may provide. Because each optimization will affect the system’s power consumption, it is critically important to be able to monitor the effects these transformations have. In this paper we present a methodology that allows designers to quickly evaluate the impact each code optimization will have in the system’s power. Our exploration engine relies on SystemC-based power/performance models to quickly and accurately evaluate the dynamic power due to memory accesses as well as the expected CPU power consumption.

The increasing demand for low power and high performance multimedia embedded systems has motivatedation bandwidth and latency requirements under a tight power budge the need for effective solutions to satisfy applict. As technology scales, it is imperative that applications are optimized to take full advantage of the underlying resources and meet both power and performance requirements. We propose a methodology capable of discovering and enabling parallelism opportunities via code transformations, efficiently distributing the computational load across resources, and minimizing unnecessary data transfers. Our approach decomposes the application's tasks into smaller units of computations called kernels, which are distributed and pipelined across the different processing resources. We exploit the ideas of inter-kernel data reuse to minimize unnecessary data transfers between kernels and early execution edges to drive performance. Our experimental results on a JPEG2000 case study show up to 80% performance improvement and 60% dynamic power reduction over standard application mapping approaches.

In this paper, we present an automated bus matrix synthesis flow for efficient system-on-chip communication design space exploration at the transaction level. Especially, we consider hardware interface design, since it affects overall system cost and performance. Depending on the bus interface, a hardware block can be a master or a slave. We propose a method to solve such hardware interface selection problem by analyzing communication behavior statically. In addition, in order to explore communication design space fast, we automatically generate transaction level models for the hardware blocks according to the hardware interface selection. The synthesis result is verified by transaction level simulation with a commercial tool. We give experimental results with JPEG encoder and H.264 encoder to demonstrate the efficiency of the proposed method. The results show that with our automated synthesis flow, the designer can easily and quickly obtain better communication designs through fast design space exploration. More specifically, our hardware interface selection technique is successful in achieving reduction of area of bus matrix by 41.43% with 0.58% performance overhead on average compared to the case of maximum performance.