• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.394-400
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• 2016

Currently, with the rapid development of the digital age, multimedia-related image devices become popular. However image deterioration is generated by multiple causes during the transmission process, with typical example of salt and pepper noise. When the noise of high density is added, existing methods are deteriorated in the characteristics of removal noise. After judging the noise condition to remove the salt and pepper noise, if the center pixel is the non-noise pixel, it is replaced with the original pixel. On the other hand, if it is the noise pixel, algorithm is suggested by the study, where the histogram of the corrupted image and the median filters are used. And for objective judgment, the proposed algorithm was compared with existing methods and PSNR(peak signal to noise ratio) was used as judgment standard. As the result of the simulation, The proposed algorithm shows a high PSNR of 32.57[dB] for Lena images that had been damaged of a high density salt and pepper noise(P=60%), Compared to the existing CWMF, A-TMF and AWMF there were improvements by 21.67[dB], 18.07[dB], and 20.13[dB], respectively.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.432-440
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• 2016

The consumption of pre-treated vegetables (including fresh-cut vegetables) that are washed, peeled, and trimmed has been significantly increased because of their easy use for cooking. Vegetable cutting machines have been widely utilized for producing fresh-cut vegetables or agricultural products of different sizes; however, the design standard is not established for specific types of agricultural products. Therefore, this study was conducted to determine mechanical properties (compressive and shear forces) of targeted agricultural products (radish, carrot, squash, cucumber, shiitake mushroom, and sweet potato) for developing a multipurpose vegetable cutting machine. According to ASAE standard (s368.3), compressive and shear forces of targeted agricultural products were measured by using a custom built UTM (universal testing machine). Shape type of samples and speed ranges (5 - 15 mm/min) of loading rate on bioyield and shear points varied depending on the targeted agricultural product. The range of averaged bioyield points of targeted agricultural products were between 7.89 and 146.98 N. On the other hand, their averaged shear points ranged from 22.50 to 53.47 N. Results clearly showed that the bioyield and shear points of targeted agricultural products were thoroughly affected by their components. As measuring compressive and shear forces of a variety of agricultural products, it will be feasible to calculate blade cutting force for designing multipurpose vegetable cutting machine.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.101-110
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• 2009

The unconscious and non-intrusive measurements of activity signals or physiological signals represent important enabling technologies for realizing a ubiquitous healthcare environment as well as a related UI. Particularly, non-intrusive measurements should be used in activity monitoring system for long-term monitoring. This paper is based on activity estimation by measuring the activity signals of a user using a handhold device with an accelerometer. The user activity estimation system (UAES) presented in this paper makes non-intrusive measurements of activity signals to minimize inconveniencing a user and to create a more practical implementation in real life. Thus, a variety of positions in which the handhold device can be carried by a user for daily use is considered, such as in the front/hip/shirt pockets, a backpack, on the waist, and in the hand.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.64-73
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• 2008

In this paper, we propose a novel objective video quality assessment method from encoded H.264/AVC.. Conventional algorithms have been proposed to assess video/image quality with image frames reconstructed in a decoder side. On the other hand, the proposed assessment is conducted with the syntax elements which are embedded in a bitstream. The proposed BS-based algorithm makes use of the statistics of boundary strength(BS) which are employed in the H.264/AVC. The proposed algorithm has lower computational complexity than conventional methods, EPSNR and Blockiness, resulting that it can accomplish assessment of the video quality in real time. Furthermore, the accuracy of the proposed video quality assessment is about 32% and 65% better than several conventional algorithms.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.116-128
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• 2020

In this study, we introduce a multi-modal mixed reality (MR) application for advertising the main touristic landmarks on Jeju Island, and evaluate its effectiveness based on the Technology Acceptance Model (TAM) with a focus on the user's involvement in Korean culture (K-Culture). Specifically, we deployed several stimuli to enable users to retrieve information, visualize a variety of heritage content such as text, images, videos, virtual artifacts, and immerse in a VR environment to experience the heritage locations. The results of the online survey with 436 participants showed that for consumers with low K-Culture involvement, Perceived Usefulness and Perceived Ease-of-Use did not affect their Intention to Visit the island. Still, it had a significant impact on their Intention to Use the application. On the other hand, for the group with high K-Culture involvement, Perceived Usefulness had no effect on the Intention to Use and Intention to Visit. However, Perceived Ease-of-Use had a significant impact on their Intention to Use the application and Intention to Visit Jeju Island. Therefore, when user involvement in K-Culture is high, convenience of use has played a significant role in sensory media usage and the intention to visit, regardless of the usefulness of the mixed reality content. In contrast, users with low K-Culture involvement primarily focused on the functional aspects of the application. These findings open the path for follow-up studies on K-Culture involvement and immersive media tourism marketing, which will benefit digital tourism marketing and Korea's tourism industry.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.591-595
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• 2010

Conventional methods of model evaluation usually rely only on model performance based on a comparison of simulated variables to corresponding observations. However, this type of model evaluation has been criticized because of its insufficient consideration of the various uncertainty sources involved in modeling processes. This study aims to propose an extended model evaluation method using multiple assesment indices (MAIs) that consider not only the model performance but also the model structure and parameter uncertainties in rainfall-runoff modeling. A simple reservoir model (SFM) and distributed kinematic wave models (KWMSS1 and KWMSS2 using topography from 250m, 500m, and 1km digital elevation models) were developed and assessed by three MAIs for model performance, model structural stability, and parameter identifiability. All the models provided acceptable performance in terms of a global response, but the simpler SFM and KWMSS1 could not accurately represent the local behaviors of hydrographs. In addition, SFM and KWMSS1 were structurally unstable; their performance was sensitive to the applied objective functions. On the other hand, the most sophisticated model, KWMSS2, performed well, satisfying both global and local behaviors. KMSS2 also showed good structural stability, reproducing hydrographs regardless of the applied objective functions; however, superior parameter identifiability was not guaranteed. Numerous parameter sets could lead to indistinguishable hydrographs. This result supports that while making a model complex increases its performance accuracy and reduces its structural uncertainty, the model is likely to suffer from parameter uncertainty. The proposed model evaluation process can provide an effective guideline for identifying a reliable hydrologic model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.521-529
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• 2020

This paper attempted to empirically analyze whether or not ethical behavior at the individual level has a positive effect on both companies and employees. In addition, based on the social exchange theory, a hypothesis was established that perceived supervisory support has a positive moderating effect on the relationship between ethical behavior, job satisfaction, and job performance. As a result of analyzing a questionnaire given to 238 sales employees, It was first verified that ethical behavior by sales staff had a positive effect on job satisfaction and performance, as expected in the hypothesis. Second, the moderating effect of perceived supervisory support was significant only in the relationship between the ethical behavior of the salesperson and job performance. On the other hand, the moderating effect of perceived supervisory support on the relationship between ethical behavior and job satisfaction was not verified. Based on the results of this study, the implications and future directions of study are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.668-675
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• 2001

Recently, the performance of the commercial PCS(Personal Communication Service) system has been improved to the uppermost limit and ultimately the next generation mobile communication is to be realized by IMT-2000 (International Mobile Communication-2000) to provide multimedia services. Therefore, the new type receiving system is researched actively and one of the most important part in a receiver is direct conversion method. The direct conversion method is suitable for low power consumption, small size, MMIC, and low price, which is to be adopted to the next generation mobile communication systems. In this case, however, several problems occur due to DC-offset. The DC-offset suppresses amplification of the required signal because of the leakage signal of frequency synthesizer in the system. In this thesis, the removing method of DC-offset was considered. There are four removing techniques of DC-offset, which are AC-coupling, large capacitor, DC-feedback loop, and DC-free coding. Among these, the AC-coupling method is the most simplest method and the DC-feedback loop method has the best performance. Then, the performance of the AC-coupling method and DC-feedback loop method are evaluated by HP's ADS simulation tool. As a result, the AC-coupling method cannot be used to the digital communication systems due to data loss. On the other hand, it was confirmed that the DC-feedback loop method is suitable for the direct conversion receiver.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.324-327
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• 2006

The person who gets a ALS(Amyotrophic Lateral Sclerosis) has language disability and physical disability together. A common first symptom is a painless weakness in a hand, foot, arm or leg, which occurs in more than half of all cases. Other early symptoms include muscle weakness of speech. In the early stage of this disease they can communicate with other persons, but it will become increasingly difficult. In our research we have designed and implemented communication tools for them. We have implemented Chunjiin(the Korean computer keyboard) at PDA(personal digital assistant). And we have also implemented software which is consisted of frequently used words.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.111-114
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• 2017

As digital contents are widely used and require increasingly high quality, the data storage services over Internet also become more and more important. One of popular services, web-hard, provides lots of users with web-based functions for data storage, management and sharing but such storage utilization requires quite high cost compared to using portable storage devices. Moreover, some users may avoid putting their important data into open Internet area. On the other hand, portable storage devices are cheaper but can be used only when they are physically connected to host devices such as PC. Also additional management and security functions should be equipped to support data sharing among users. In this paper, we propose a web-based data storage system combining those advantages of aforementioned two approaches. The proposed system immediately provides web-based services for data management and sharing when a portable device such as SDD is connected to the server.