Corporate Governance and International Portfolio Investment in Equities

Previous articles examined international portfolio investments either by a single investor or to a single destination. We examine the determinants of international equity investment patterns using multiple pairs of source and host countries. Specifically, we investigate how the corporate governance institutions in investing and recipient countries are associated to equity investment and divestiture using the 2006 and 2008 Coordinated Portfolio Investment Survey (CPIS) data. We find that source countries buy equities in host countries with strong governance more than in host countries with weak governance. We also find that investors from strong governance countries disproportionately sell more their equities in weak governance countries during the recent economic crisis. However, investors from weak governance countries do not demonstrate such divestiture pattern

Development of a 2-Channel Embedded Infrared Fiber-Optic Temperature Sensor Using Silver Halide Optical Fibers

A 2-channel embedded infrared fiber-optic temperature sensor was fabricated using two identical silver halide optical fibers for accurate thermometry without complicated calibration processes. In this study, we measured the output voltages of signal and reference probes according to temperature variation over a temperature range from 25 to 225 °C. To decide the temperature of the water, the difference between the amounts of infrared radiation emitted from the two temperature sensing probes was measured. The response time and the reproducibility of the fiber-optic temperature sensor were also obtained. Thermometry with the proposed sensor is immune to changes if parameters such as offset voltage, ambient temperature, and emissivity of any warm object. In particular, the temperature sensing probe with silver halide optical fibers can withstand a high temperature/pressure and water-chemistry environment. It is expected that the proposed sensor can be further developed to accurately monitor temperature in harsh environments

Prostate Specific Membrane Antigen mRNA in Blood as a Potential Predictor of Biochemical Recurrence after Radical Prostatectomy

We investigated whether the detection of prostate specific membrane antigen (PSMA) in blood preoperatively has predictive value for biochemical recurrence (BCR) after radical prostatectomy in patients with prostate cancer. All 134 patients scheduled to receive radical prostatectomy for prostate cancer were prospectively enrolled. The authors used nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect PSMA mRNA-bearing cells in peripheral blood, and analyzed the ability of PSMA mRNA positivity to predict BCR after surgery. PSMA-mRNA was detected in 24 (17.9%) patients by RT-PCR. Over a median follow-up of 20 months (range, 3 to 46 months), BCR developed in 15 patients (11.2%) and median time to BCR was 7 months (range, 3 to 25 months). Kaplan-Meier analysis revealed a significant difference between those positive or negative for PSMA in terms of recurrence-free actuarial probability (log rank P=0.0039). Multivariate analysis showed that positivity for PSMA mRNA (HR: 3.697, 95% CI 1.285-10.634, P=0.015) and a biopsy Gleason score of ≥7 (HR: 4.500, 95% CI 1.419-14.274, P=0.011) were independent preoperative predictors of BCR. The presence of PSMA mRNA in peripheral blood can be used to predict BCR after radical prostatectomy

Relationships among Experience Economy, Tour Quality, Tour Satisfaction, and Word-of-Mouth in the Senior Tourism Context in Korea: The Moderating Role of Tour Guiding Services

The senior tourist market is growing, because the number of elderly people is increasing in Korea. It is widely accepted that experience in travel is more important than any other factor. Thus, the aim of this study was to examine the importance of the experience economy and its impact on outcome variables with the moderating role of tour guiding services in the senior tourism industry. This study more specifically proposed that there is a positive relationship between the four dimensions of the experience economy, which include education, entertainment, aesthetics, and escapism, and tour quality. In addition, it was proposed that tour quality has a positive influence on tour satisfaction and word-of-mouth. Lastly, this study investigated the moderating role of a tour guide service in the relationship between the experience economy and tour quality. The data were collected from 323 seniors who had experienced an overseas package tour in Korea. In order to test the proposed model, this study employed confirmatory factor analysis and structural equation modeling analysis. The data analysis results indicated that entertainment and aesthetics play a significant role in the formation of tour quality. The results of the data analysis also showed that tour quality has a positive influence on tour satisfaction, which in turn positively affects word-of-mouth. Furthermore, a tour guide service moderated the relationship between aesthetics and tour quality

On the L2-discrepancy

AbstractFor a family of subsets S of a finite set V, a coloring χ:V→{-1,1}, and Sj∈S, let χ(Sj)=∑v∈Sjχ(v). We consider the problem to minimize ∑jχ(Sj)2 and we call the problem L2-discrepancy problem. We show that the problem is NP-complete, and we also provide an upper bound for the L2-discrepancy

Relationship between the Engel Coefficient, Life Satisfaction, and Subjective Health for Senior Citizens in Korea: Moderating Effect of COVID-19

The purpose of this study was to explore the determinants of life satisfaction for Korean senior citizens. Subjective health and the Engel coefficient were used as the explanatory variables. This research also aimed to examine the moderating effect of Coronavirus disease 2019 (COVID-19) on the relationship between the Engel coefficient and life satisfaction for Korean senior citizens. Archival data (Korean longitudinal study of aging) were used for this work. The study period is 2018 and 2020; the number of observations was 3879. Multiple linear regression analysis was performed to test the research hypotheses. To examine further, this research performed additional analyses: sub-sample analysis, median split, and independence tests. The results indicated that the Engel coefficient is negatively associated with life satisfaction, while subjective health is positively related to life satisfaction. Moreover, Korean senior citizens’ life satisfaction was higher during the COVID-19 pandemic. This research provides information for building policy for senior Korean citizens

Structural Relationship between Attributes of Technology Acceptance for Food Delivery Application System: Exploration for the Antecedents of Perceived Usefulness

The aim of this research is to explore the antecedents of usefulness in the technology acceptance model for a food delivery application system and to confirm the accountability of the technology acceptance model in the area of food delivery application systems. The determinants of usefulness are information quality, swiftness, and food quality. For data collection, this research employs Amazon Mechanical Turk. The number of valid observations is 379. For the data analysis, confirmatory factor analysis and structural equation modeling were primarily implemented. The results indicate that usefulness is positively impacted by information quality, swiftness, and ease of use. Additionally, it is found that attitude is positively influenced by usefulness. Moreover, intention to use is positively affected by usefulness and attitude. This research is worthwhile in that it provides service providers with information for constructing better systems

Ranked Subsequence Matching in Time-series Databases

Existing work on similar sequence matching has focused on either whole matching or range subsequence matching. In this paper, we present novel methods for ranked subsequence matching under time warping, which finds top-k subsequences most similar to a query sequence from data sequences. To the best of our knowledge, this is the first and most sophisticated subsequence matching solution mentioned in the literature. Specifically, we first provide a new notion of the minimum-distance matching-window pair (MDMWP) and formally define the mdmwp-distance, a lower bound between a data subsequence and a query sequence. The mdmwp-distance can be computed prior to accessing the actual subsequence. Based on the mdmwp-distance, we then develop a ranked subsequence matching algorithm to prune unnecessary subsequence accesses. Next, to reduce random disk I/Os and bad buffer utilization, we develop a method of deferred group subsequence retrieval. We then derive another lower bound, the window-group distance, that can be used to effectively prune unnecessary subsequence accesses during deferred group-subsequence retrieval. Through extensive experiments with many data sets, we showcase the superiority of the proposed methods.1

Ultra-high-definition holography for near-eye display

Holographic near-eye displays (NEDs) have large potential for augmented reality (AR) devices as they modulate the wavefront of light. They can provide observers with comfortable three-dimensional (3D) views with focus-cues, and little optical aberrations since the unwanted phase delay added by optical systems can be compensated by wavefront modulation. With the advent of ultra-high-definition (UHD) spatial light modulator (SLM), a degree of freedom in designing holographic NEDs has been further expanded. Here, we introduce several holographic NEDs using UHD SLM. The holographic NED using an HOE is introduced for the optical see-through display. Besides, the holographic NED with enlarged eye-box using point-source array and eye-tracking method will be presented. Finally, the holographic NED of which optical aberration is compensated by Zernike's polynomial adaptation will be introduced.N

Scalable Name Lookup for NDN Using Hierarchical Hashing and Patricia Trie

Named data networking (NDN) is a content-centric network for the future of the internet. An NDN a packet is delivered based on a content name instead of a destination IP address. The name lookup for packet forwarding is challenging because the content name is variable, and its space is unbounded. This paper proposes a novel name lookup scheme that employs a hashing technique combined with Patricia tries. In this scheme, hash tables are dynamically maintained according to the hierarchical structure of the name, so the name can effectively accommodate variable and unbounded content names. Unlike chaining, a Patricia trie compares a key string only once at a leaf node, so it provides a fast name lookup. The proposed lookup scheme is implemented and evaluated by using an Intel Core i7-2600 CPU and 4GB of memory. Experimental results show that our scheme gives good scalability and a high throughput of name lookup with a controlled memory consumption