• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.44 no.4 s.316
• /
• pp.36-44
• /
• 2007

In this paper, we implement the speech & face recognition system to support various ubiquitous sensor network application services such as switch control, authentication, etc. using wireless audio and image interface. The proposed system is consist of the H/W with audio and image sensor and S/W such as speech recognition algorithm using psychoacoustic model, face recognition algorithm using PCA (Principal Components Analysis) and LDPC (Low Density Parity Check). The proposed speech and face recognition systems are inserted in a HOST PC to use the sensor energy effectively. And improve the accuracy of speech and face recognition, we implement a FEC (Forward Error Correction) system Also, we optimized the simulation coefficient and test environment to effectively remove the wireless channel noises and correcting wireless channel errors. As a result, when the distance that between audio sensor and the source of voice is less then 1.5m FAR and FRR are 0.126% and 7.5% respectively. The face recognition algorithm step is limited 2 times, GAR and FAR are 98.5% and 0.036%.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.4 s.42
• /
• pp.35-45
• /
• 2006

RIn this paper. we describe real-time parallel processing simulator developed for the use of performance analysis of rolling missiles. The real-time parallel processing simulator developed here consists of seeker emulator generating infrared image signal on aircraft, real-time computer, host computer, system unit, and actual equipments such as auto-pilot processor and seeker processor. Software is developed according to the design requirements of mathematic model, 6 degree-of-freedom module, aerodynamic module which are resided in real-time computer. and graphic user interface program resided in host computer. The real-time computer consists of six TI C-40 processors connected in parallel. The seeker emulator is designed by using analog circuits coupled with mechanical equipments. The system unit provides interface function to match impedance between the components and processes very small electrical signals. Also real launch unit of missiles is interfaced to simulator through system unit. In order to use the real-time parallel processing simulator developed here as a performance analysis equipment for rolling missiles, we perform verification test through experimental results in the field.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2021.11a
• /
• pp.446-448
• /
• 2021

In training a deep learning model, it is crucial to tune various hyperparameters and gain speed and accuracy. While hyperparameters that mathematically induce convergence impact training speed, system parameters that affect host-to-device transfer are also crucial. Therefore, it is important to properly tune and select parameters that influence the data loader as a system parameter in overall time acceleration. We propose an automated framework called Num Worker Tuner (NWT) to address this problem. This method finds the appropriate number of multi-processing subprocesses through the search space and accelerates the learning through the number of subprocesses. Furthermore, this method allows memory efficiency and speed-up by tuning the system-dependent parameter, the number of multi-process spawns.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.10 no.2
• /
• pp.122-128
• /
• 2000

With the rising innovative antigens(such as intruders and viruses) through Internet, new secure schemes are expected to perceptively detect and put them down. However, the current hosts over Internet could not properly analyze Internet antigens due to limitations of their system and network resources. In this paper, we introduce an Antibody Layer that mediates proper security services based on the biological mechanism to mpidly disclose and remove innovative antigens. The proposed Antibody Layer also provides three classes to make agreed-on security parameters set up easily with respect to real-time security QoS for one host as well as host alliances.

• Journal of Korea Trade
• /
• v.25 no.1
• /
• pp.133-151
• /
• 2021

Purpose - This study examines the effects of expatriate transfer on foreign affiliate's labor productivity. Design/methodology - Using Korean-owned foreign affiliate-level data, we estimate the effect of expatriate transfer on foreign affiliate's labor productivity using the system generalized method of moments model. We also consider foreign affiliate- and host country-specific contingencies and test how they are associated with expatriates in enhancing foreign affiliate's labor productivity. Findings - We consider foreign production intensity and cultural distance between the home (i.e., South Korea) and host countries as key contingencies that influence the effect of expatriates on foreign affiliate's labor productivity. We find that expatriates are effective in enhancing the labor productivity of less production-intensive foreign affiliates. This effect is strengthened as expatriates are deployed to countries that share cultural similarities with the home country. Originality/value - Considering that previous studies provide mixed results on the effect of expatriates, our findings suggest that foreign affiliate-specific operational orientation and cultural distance should be considered jointly to understand the true effect of expatriate staffing on foreign affiliate performance.

• Journal of KIISE:Software and Applications
• /
• v.29 no.1_2
• /
• pp.30-41
• /
• 2002

We focus on the mobile agents which are considered as new paradigm to solve information retrieval of large volumes of data in the distributed and heterogeneous environment. The mobile agent moves the computation to data instead of large volumes of data to computations. In this paper, we propose an information retrieval model, which can effectively search data in the distributed and heterogeneous environment, using mobile agents. Our model is applied to the design and implementation of an Q&A(Question and Answer) retrieval system. Our Q&A retrieval system, called QASSMA(Q&A Search System using Mobile Agents), uses mobile agents to retrieve articles from Q&A boards and newsgroups that exist in the heterogeneous and distributed environment. QASSMA has the following features and advantages. First, the mobile retrieval agent moves to the destination server to retrieve articles to reduce the retrieval time by eliminating data traffics from the server to the client host. Also it can reduce the traffic that was occurred in the centralized network system, and reduce the usage of resources by sending its agent and running in the destination host. Finally, the mobile retrieval agent of QASSMA can add and update dynamically the class file according to its retrieval environment, and support other retrieval manner. In this paper, we have shown that our Q&A retrieval system using mobile agents is more efficient than the retrieval system using static agents by our experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.10
• /
• pp.1712-1732
• /
• 2011

Cloud provides dynamically scalable virtualized computing resources as a service over the Internet. To achieve higher resource utilization over virtualization technology, an optimized strategy that deploys virtual machines on physical machines is needed. That is, the total number of active physical host nodes should be dynamically changed to correspond to their resource usage rate, thereby maintaining optimum utilization of physical machines. In this paper, we propose a pattern-based prediction model for resource provisioning which facilitates best possible resource preparation by analyzing the resource utilization and deriving resource usage patterns. The focus of our work is on predicting future resource requests by optimized dynamic resource management strategy that is applied to a virtualized data center in a Cloud computing environment. To this end, we build a prediction model that is based on user request patterns and make a prediction of system behavior for the near future. As a result, this model can save time for predicting the needed resource amount and reduce the possibility of resource overuse. In addition, we studied the performance of our proposed model comparing with conventional resource provisioning models under various Cloud execution conditions. The experimental results showed that our pattern-based prediction model gives significant benefits over conventional models.

• Journal of Mechanical Science and Technology
• /
• v.19 no.3
• /
• pp.905-912
• /
• 2005

A computational investigation of blood flow in a coronary artery grafted by artificial bypass was performed to determine such geometric parameters as the curvature of radius, approach length, and angle of end-to-side anastomosis. Transient flow features in the host artery were computed using FVM and SIMPLE algorithms. We compared flow distributions and wall shear stresses in two simple models, planar and non-planar, and confirmed that the non-planar bypass model was more conducive to suppressing intimal hyperplasia. Our non-planar model with $60^{\circ}$ of anastomosis and a 1.0 diameter approach length and radius of curvature predicts a relatively small, spatially-extended high-OSI (>0.01) zone, as well as an increased average wall shear stress on this zone.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.872-875
• /
• 2002

A digital watermarking technique applying psychoacoustic model for audio signal is proposed in this paper. In the watermarking scheme, the pseudo-random bit stream used as a watermark signal is embedded into the audio signal in both speech and music. The strength of the embedded signal is subject to the human auditory system in such a way that the disturbances on host audio signal are beyond the sensing of human ears. The experimental results show that the quality of the watermarked audio signal, in term of signal to noise ratio, can be improved up to 3.2 dB.

• International Journal of Stem Cells
• /
• v.15 no.1
• /
• pp.3-13
• /
• 2022

The current COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has completely changed human life for more than two years. Upon the emergence of this new lethal virus, multiple approaches were utilized to gain basic knowledge about its biology. Moreover, modern technologies, such as the organoid model system and next-generation sequencing, enabled us to rapidly establish strategies to tackle the disease, including vaccines and therapeutics. The recently developed organoid technology reflects human physiology more closely than other model systems. Coupled with its rapidness, high efficiency, and outstanding reliability, it has provided an opportunity to develop new drugs and understand the impact of the viral pathogen on the host. Recent findings using organoids have successfully revealed the cellular tropism of the virus in different organs and identified potential drug candidates that impact the disease. This review will summarize current achievements made with organoids in the fight against COVID-19.