This study investigates the impact of nondriving-related task (NDRT) interface design, specifically the choice of display and control modalities, on the severity of autonomous vehicle motion sickness (AV MS) and passenger preference. Participants completed a letter 2-back task under four different interface conditions: visual-manual, visual-speech, auditory-manual, and auditory-speech. The Motion Sickness Assessment Questionnaire was used to measure MS levels before and after each on-road trial. Results indicated that MS severity was significantly lower for auditory display than for visual display, while control modality had no significant effect. In terms of preference, participants showed a higher preference for visual interfaces in the in-laboratory environment, whereas auditory and speech control interfaces were preferred in the on-road environment. These findings suggest that optimizing NDRT interface design, particularly through the use of auditory displays and speech controls, can mitigate AV MS and enhance passenger comfort. This research contributes to the ongoing efforts to improve user experience and acceptance of AV technology.

With the increasing aging population, chronic pain and musculoskeletal disorders have become significant health concerns, leading to a growing demand for non-invasive pain management strategies such as transcutaneous electrical nerve stimulation (TENS). While TENS is widely used for pain relief and neuromuscular regulation, sex differences in physiological responses remain underexplored. This study investigates sex-specific autonomic nervous system (ANS) and electromyography (EMG) responses to TENS stimulation at varying intensities (3VPP, 7VPP, and 11VPP) in 31 participants (16 males, 15 females). ECG and EMG signals were recorded using the BIOPAC MP36 system, and key HRV and EMG parameters were analyzed to assess neural and muscular activation patterns. Results showed that females exhibited broader neuromuscular responses at lower intensities, whereas males demonstrated increased autonomic activity at higher intensities, supporting the Gate Control Theory. These findings highlight the necessity of sex-specific electro stimulation therapy strategies and contribute to optimizing personalized TENS treatments.

The Simon's congruence problem is to determine whether or not two strings have the same set of subsequences of length no greater than a given integer, and the problem can be answered in linear time. We consider the Simon's congruence pattern matching problem that looks for all substrings of a text that are congruent to a pattern under the Simon's congruence. We propose a linear time algorithm by reusing results from previous computations with the help of new data structures called X-trees and Y-trees. Moreover, we investigate several variants of the problem such as identifying the shortest substring or subsequence of the text that is congruent to the pattern under the Simon's congruence, or finding frequent matchings. We design efficient algorithms for these problems. We conclude the paper with two open problems: finding the longest congruent subsequence and optimizing the pattern matching problem.

As interest in cryptocurrency has increased, problems have arisen with Proof-of-Work (PoW) and Proof-of-Stake (PoS) methods, the most representative methods of acquiring cryptocurrency in a blockchain. The PoW method is uneconomical and the PoS method can be easily monopolized by a few people. To cope with this issue, this paper introduces a Proof-of-Probability (PoP) method. The PoP is a method where each node sorts the encrypted actual hash as well as a number of fake hash, and then the first node to decrypt actual hash creates block. In addition, a wait time is used when decrypting one hash and then decrypting the next hash for restricting the excessive computing power competition. In addition, the centralization by validaters with many stakes can be avoided in the proposed PoP method.

Dynamic scripting languages are becoming more and more widely adopted not only for fast prototyping but also for developing production-grade applications. They provide high-productivity programming environments featuring high levels of abstraction with powerful built-in functions, automatic memory management, object-oriented programming paradigm and dynamic typing. However, their flexible, dynamic type systems easily become the source of inefficiency in terms of instruction count, memory footprint, and energy consumption. This overhead makes it challenging to deploy these high-productivity programming technologies on emerging single-board computers for IoT applications. Addressing this challenge, this paper introduces Typed Architectures, a high-efficiency, low-cost execution substrate for dynamic scripting languages, where each data variable retains high-level type information at an ISA level. Typed Architectures calculate and check the dynamic type of each variable implicitly in hardware, rather than explicitly in software, hence significantly reducing instruction count for dynamic type checking. Besides, Typed Architectures introduce polymorphic instructions (e.g., xadd), which are bound to the correct native instruction at runtime within the pipeline (e.g., add or fadd) to efficiently implement polymorphic operators. Finally, Typed Architectures provide hardware support for flexible yet efficient type tag extraction and insertion, capturing common data layout patterns of tag-value pairs. Our evaluation using a fully synthesizable RISC-V RTL design on FPGA shows that Typed Architectures achieve geomean speedups of 11.2% and 9.9% with maximum speedups of 32.6% and 43.5% for two production-grade scripting engines for JavaScript and Lua, respectively. Moreover, Typed Architectures improve the energy-delay product (EDP) by 19.3% for JavaScript and 16.5% for Lua with an area overhead of 1.6% at a 40nm technology node.

One of the risks of the endonasal approach to skull base surgery is inadvertent damage to one of the two carotid arteries that are located behind the bone being drilled. Photoacoustic imaging, which combines a pulsed laser with an ultrasound receiver probe, has been shown to be able to image blood vessels behind bone. We therefore integrated a photoacoustic imaging system with a telerobotic system, where the pulsed laser is delivered via an optical fiber attached to the drill held by one robot arm and the ultrasound receiver is positioned, at some distance from the drilling site, by another robot arm. This paper describes a new method for accurately determining the safe region for drilling, which is defined by the center-line between the two carotid arteries, and presents the first phantom experiments with this system. The results show that the system can determine the center point with an accuracy better than 2 mm, which suggests that it may be sufficient for clinical scenarios where the two carotid arteries can be within 8 mm of each other.

The determination of a flexible needle shape during the insertion is an important issue in minimally invasive surgery techniques. This is especially critical when considering conventional surgery procedures where a surgeon usually determines how to proceed needle insertion further based on the current needle trajectory inserted into tissue during biopsy and removal of malignant tissues in the body. In this paper, we propose a new method to determine the shape of a needle that is being inserted, together with the curvature measurement data obtained by fiber Bragg gratings (FBG) sensors inside the needle. This approach can be particularly advantageous to the situations where visual guidance (such as by ultrasound probes) is not easily applicable. The description of a needle shape is based on the elastic rod theory and Lie-group-theoretic approach. We also present the comparison between two different calibration methods, which have an impact on the quality of the results of the proposed method. In order to verify the proposed method, needle trajectories by the model are compared with experimental data obtained by image analysis, which in turn emphasizes the capability of the proposed method.

Interpreters are widely used to implement high-level language virtual machines (VMs), especially on resource-constrained embedded platforms. Many scripting languages employ interpreter-based VMs for their advantages over native code compilers, such as portability, smaller resource footprint, and compact codes. For efficient interpretation a script (program) is first compiled into an intermediate representation, or bytecodes. The canonical interpreter then runs an infinite loop that fetches, decodes, and executes one bytecode at a time. This bytecode dispatch loop is a well-known source of inefficiency, typically featuring a large jump table with a hard-to-predict indirect jump. Most existing techniques to optimize this loop focus on reducing the misprediction rate of this indirect jump in both hardware and software. However, these techniques are much less effective on embedded processors with shallow pipelines and low IPCs. Instead, we tackle another source of inefficiency more prominent on embedded platforms - redundant computation in the dispatch loop. To this end, we propose Short-Circuit Dispatch (SCD), a low cost architectural extension that enables fast, hardware-based bytecode dispatch with fewer instructions. The key idea of SCD is to overlay the software-created bytecode jump table on a branch target buffer (BTB). Once a bytecode is fetched, the BTB is looked up using the bytecode, instead of PC, as key. If it hits, the interpreter directly jumps to the target address retrieved from the BTB, otherwise, it goes through the original dispatch path. This effectively eliminates redundant computation in the dispatcher code for decode, bound check, and target address calculation, thus significantly reducing total instruction count. Our simulation results demonstrate that SCD achieves geomean speedups of 19.9% and 14.1% for two production-grade script interpreters for Lua and JavaScript, respectively. Moreover, our fully synthesizable RTL design based on a RISC-V embedded processor shows that SCD improves the EDP of the Lua interpreter by 24.2%, while increasing the chip area by only 0.72% at a 40nm technology node.

We are investigating the use of photoacoustic (PA) imaging to detect critical structures, such as the carotid artery, that may be located behind the bone being drilled during robot-assisted endonasal transsphenoidal surgery. In this system, the laser is mounted on the drill (via an optical fiber) and the 2D ultrasound (US) probe is placed elsewhere on the skull. Both the drill and the US probe are tracked relative to the patient reference frame. PA imaging provides two advantages compared to conventional B-mode US: (1) the laser penetrates thin layers of bone, and (2) the PA image displays targets that are in the laser path. Thus, the laser can be used to (non-invasively) extend the drill axis, thereby enabling reliable detection of critical structures that may reside in the drill path. This setup creates a challenging alignment problem, however, because the US probe must be placed so that its image plane intersects the laser line in the neighborhood of the target anatomy (as estimated from preoperative images). This paper reports on a navigation system developed to assist with this task, and the results of phantom experiments that demonstrate that a critical structure can be detected with an accuracy of approximately 1 mm relative to the drill tip.

Community detection has been one of the fundamental problems in network analysis. Results from community detection (for example, grouping of products by latent category) can also serve as information nuggets to other business applications, such as product recommendation or taxonomy building. Because several real networks are naturally directed, e.g. World Wide Web, some recent studies proposed algorithms for detecting various types of communities in a directed network. However, few of them considered that nodes play two different roles, source and terminal, in a directed network.

For industrial applications requiring medium and high-power supplies modular multilevel converter (MMC) based voltage source converters (VSC) offer advantages over traditional VSCs. These include achievement of higher voltage levels with utilization of lower voltage power semiconductor devices. The control structure of MMC for fault operating condition is proposed in this paper, and dynamic performance of the MMC based on the proposed control structures is further investigated in PSCAD/EMTDC environment. Real Time Digital Simulator (RTDS) results are also presented to verify the controller performance under normal and fault operating conditions.

The Convertible static transmission controller is a versatile device which can be installed across a transmission transformer to extend the life time of existing transformers by partially bypassing and conditioning the substation throughput power. The proposed technology can provide several integration options with multiple operational modes. From the supervisory control point of view, a control algorithm is required to set the reference values of active and reactive power flow of CSTC converters based on the desired operating points for transformer active and reactive power. In this paper, the algebraic model of CSTC in shunt-shunt mode of operation is derived. Algebraic model of CSTC is used for steady state and transient stability analysis. Algebraic model will present the behavior of transformer power flow with respect to various operating points of CSTC converters. The P-Q transformer operating range can be obtained based on the proposed algebraic model. Dynamic performance of the CSTC system is also investigated in PSCAD/EMTDC environment. Simulation results will be presented to verify the proposed algebraic model of CSTC in shunt-shunt mode of operation based on steady state results.

In this paper, an advanced preoperative planning framework for spinal fusion is presented. The framework is based on spinal pedicle data obtained from computed tomography (CT) images, and provides optimal insertion trajectories and pedicle screw sizes. The proposed approach begins with a safety margin estimation for each potential insertion trajectory that passes through the pedicle volume, followed by procedures to collect a set of insertion trajectories that satisfy operation safety objectives. Among the trajectory candidates, the insertion trajectory, which maximizes the insertable depth of a pedicle screw into the vertebral body, is then chosen as optimal, because the insertable depth enhances the strength of the transpedicular screw-vertebra interface after spinal fusion surgery. The radius of a pedicle screw was chosen as 70% of the pedicle radius. This framework has been tested on 68 spinal pedicles of 8 patients requiring spinal fusion. It was successfully applied, resulting in an average success rate of 100% and a final safety margin of 2.11±0.17mm.

This paper presents a full-body gesture database which contains 2D video data and 3D motion data of 14 normal gestures, 10 abnormal gestures and 30 command gestures for 20 subjects. We call this database the Korea University Gesture (KUG) database. Using 3D motion cameras and 3 sets of stereo cameras, we captured 3D motion data and 3 pairs of stereo-video data in 3 different directions for normal and abnormal gestures. In case of command gestures, 2 pairs of stereo-video data were obtained by 2 sets of stereo cameras with different focal lengths in order to capture views of whole body and upper body, simultaneously. The 2D silhouette data was synthesized by separating a subject and background in 2D stereo-video data. In this paper, we describe the gesture capture system, the organization of database, the potential usages of the database and the contact point for the KUG database. We expect that this database would be very useful for the study of 2D/3D human gesture and its application.

Several robotic surgical systems have been developed for MIS (minimally invasive surgery) including commercialized products such as da Vinci and ZEUS. We have developed a minimally invasive surgical system, which have carried out remote surgery experiments for five times at the writing time. In this paper, a remote surgery experiment, which was conducted between Japan and Korea by using the developed minimally invasive surgical system is described. Research & Development (R & D) Internet testbet, APII (Asia-Pacific Information Infrastructure), which consists of an optical submarine cable network KJCN (Korea-Japan Cable Network), was used. In the experiment, a laparoscopic cholecystectomy was successfully carried out on a pig. The network time-delays of control signal and images were 6.5 msec and 435.5 msec respectively. A comparison of remote surgery experiments using ISDN and the Internet was studied

The goal of this work is to develop a robot-assisted surgery system for spinal fusion, which is composed of a robot, a surgical planning system, and an optical tracking system. The system plays roles of assisting surgeon for inserting a pedicle screw in spinal fusion. Compared to pure navigation systems as well as conventional methods for spinal fusion, it is able to achieve better accuracy through compensating for the portending movement of the surgical area. Furthermore, the robot can position and guide needles, drills, and other surgical instruments or conducts drilling/screwing directly. In preoperative surgery, the desired entry point, orientation, and depth of surgical tools for pedicle screw insertion are determined by the surgical planning system based on CT or MR images. Intra-operatively, the position information on the surgical instruments and the targeted surgical areas are obtained by the tracking system and, using that information, a robot conducts the preplanned operation depending on its role while compensating the movement of the surgical area. Two exemplary experiments employing the developed robot-assisted surgery system are conducted.