• Journal of Digital Contents Society
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• v.19 no.4
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• pp.719-729
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• 2018

Abstract In 2017, it has been reported that Google had more than 90% of the market share in search-engines of desktops and mobiles. Most people may consider that Google surely searches the entire web area. However, according to many researches for web data, Google only searches less than 10%, surprisingly. The most region is called the Deep Web, and it is indexable by special search engines, which are different from Google because they focus on a specific segment of interest. Those engines build their own deep-web databases and run particular algorithms to provide accurate and professional search results. There is no search engine that indexes the entire Web, currently. The best way is to use several search engines together for broad and efficient searches as best as possible. This paper defines that kind of search engine as Hybrid Search Engine and provides characteristics and differences compared to conventional search engines, along with a frame of hybrid search engine.

• Journal of KIISE
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• v.44 no.3
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• pp.223-231
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• 2017

In this paper, we study the performance of recently popular multi-core systems in mobiles. Previous research on the multi-core performance usually focused on the desktop PC. However, there is enough scope to further analyze heterogeneous multi-core systems. Therefore, by extending homogeneous multi-core systems, we analyze the heterogeneous multi-core systems using Size Interval Task Allocation (SITA) for job allocation, and Shortest Remaining Processing Time (SRPT) scheduling, for each individual core. We propose a new computational method regarding the cutoff point, which is crucial in analyzing SITA, by calculating the sojourn time. This facilitate easy and accurate calculation of the sojourn time. We further confirm our analysis through the ESESC simulator that provides actual measurements.

• KIISE Transactions on Computing Practices
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• v.22 no.7
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• pp.320-325
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• 2016

By developing the IoT(Internet of Things) technology, devices for smart home environment have rapidly increased. With respect to mobiles, these applications are used to control and manage the various smart devices effectively. However, the existing mechanisms only provide simple information, and hence a difficulty to search or control the smart devices persists, since there is no meaningful relationship between them. In this research, we suggest an interface which visualizes the device's data and controls them effectively, based on the user's device using pattern. As a solution for this problem, we classify the user pattern based on a timeline for the associated circumstance, and visualize the device's data to make a group or to control individually in an easier approach. Also, all meaningful information could be confirmed by summarizing all the data of smart devices.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.367-380
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• 2015

This paper proposes a hybrid rendering method which combines pre-computed global illumination results and interactive local illumination techniques and thus could interactively produce photo-realistic visual effects for mobile entertainment applications. The proposed method uses the programmable shading capability of OpenGL, a de facto standard for computer graphics library so that it can be deployed in a real-world development environment. Also, it increases the rendering time by a negligible amount compared to normal rendering time since the pre-computed results are used as operands of plain arithmetic operations. Therefore it is expected to be applicable in practice for mobiles games which require real-time responsiveness to users.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1233-1246
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• 2018

With the proliferation of smart mobiles, disassembly techniques for position-independent code (PIC) composed of ARM architecture instructions in computer security are becoming more important. However, existing techniques have been studied on x86 architecture and are focused on solving problems of non-PIC and generality. Therefore, the accuracy of the collected address information is low to apply to advanced security technologies such as binary measurement. In this paper, we propose a disassembly technique that reflects the characteristics of PIC composed of ARM instructions. For accuratly collecting traceable addresses, we designed value-set analysis having symbol-form domain. To solve the main problem of disassembly, we devised a heuristic using the characteristics of the code generated by the compiler. To verify the accuracy and effectiveness of our technique, we tested 669 shared libraries and executables in the Android 8.1 build, resulting in a total disassembly rate of 91.47%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5276-5298
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• 2019

Internet of Things (IoT) based sensor networks have gained unprecedented popularity in recent years. With the exponential explosion of the objects (sensors and mobiles), the bandwidth and the speed of data transmission are dwarfed by the anticipated emergence of IoT. In this paper, we propose a novel heterogeneous IoT model integrated the power line communication (PLC) and WiFi network to increase the network capacity and cope with the rapid growth of the objects. We firstly propose the mean transmission delay calculation algorithm based the 3D Markov chain according to the multi-priority of the objects. Then, the attractor selection algorithm, which is based on the adaptive behavior of the biological system, is exploited. The combined the 3D Markov chain and the attractor selection model, named MASM, can select the optimal path adaptively in the heterogeneous IoT according to the environment. Furthermore, we verify that the MASM improves the transmission efficiency and reduce the transmission delay effectively. The simulation results show that the MASM is stable to changes in the environment and more applicable for the heterogeneous IoT, compared with the other algorithms.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.188-194
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• 2002

DBS is utilized as very useful media in information-oriented society because it covers wide service area and provide high quality services. But DBS needs skill that can receive DBS signal at move. In this paper, it is considered a development of a device to receive DBS and design of a low noise downconverter that use tracking antenna to receive DBS at mobiles unit and ships which navigate in Korea peninsula coast. The structure of dual phase LNB is composed of LNA, BPF, oscillator, mixer, and IF amplifier. And for the position tracking, two input-output phase performed in phase. Measured results showed good performance that with respect to input signal 11.7 GHz~12.2 GHz, noise figure is 0.87 dBmax and conversion gain 62 dB, temperature characterization ${\pm}400$ kHz in respect to - 30 to $60^{\circ}C$, and phase noise -101 dBc/Hz in respect to offset 100 kHz.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2347-2350
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• 2015

Childhood acute lymphoblastic leukemia (ALL) is one of the most common hematologic malignancies, accounting for one fourth of all childhood cancer cases. Exposure to environmental factors around the time of conception or pregnancy can increase the risk of ALL in the offspring.This study aimed to evaluted the role of prenatal and postnatal exposure to high voltage power lines on the incidence of childhood ALL.This cross-sectional case control study was carried out on 22 cases and 100 controls who were born and lived in low socioeconomic families in Isfahan and hospitalized for therapeutic purposes in different hospitals from 2013-2014.With regard to the underlying risk factors, familial history and parental factors were noted but in this age, socioeonomic and zonal matched case control study, prenatal and childhood exposure to high voltage power lines was considered as the most important environmental risk factors of ALL (p=0.006, OR=3.651, CI 95%, 1.692-7.878). As the population was of low socioeconomic background, use of mobiles, computers and microwave was negligible. Moreover prenatal and postnatal exposure to indoor electrically charged objects was not determined to be a significant environmental factor. Thus, pre and post natal exposure to high voltage power lines and living in pollutant regions as well as familial influence could be described as risk factors of ALL for the first time in a low socioeconomic status Iranian population.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.9-15
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• 2016

In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by mobile cranes. Fatal injury analyses were conducted with several accident cases by the mobile cranes. For each accident, the causes of the injuries were examined and proper safety measures were proposed. This study proposed a revision of the standard guideline as an accident prevention measures through in-depth analysis of fatal accidents. First, fatality rate per 10,000 persons by the mobiles cranes was 0.57 in 2011. Second, the in-depth analysis of the mobile crane accidents showed that the main factors of the accidents were the overturn of mobile crane, the fracture of connection part between mobile crane boom and rope, the breaking of rope and the misunderstanding over the signal between a mobile crane driver and workers around a mobile crane. Third, the order of high defection of connecting parts was bucket bolt, bracket and extension parts. Fourth, since there were several cases of overturn of mobile crane by itself in the in-depth analysis of the mobile crane, the over slop-proof device was proposed as the main alternative in this study. Fifth, the revision of standards of safety factor that shall be more than 10, of connecting parts of mobile crane was proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6A
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• pp.820-831
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• 1999

In this paper, we have compared the performance of a D-TDMA protocol with that of a CDMA protocol, in radio access system for integrated voice/data services.The D-TDMA protocol is based on a generic dynamic channel assignment approach to be followed a combination of “circuit mode” reservation for voice calls, along with dynamic first-come-first served assignment of remaining capacity for data messages. In the CDMA protocol, we have used the voice activity detection to reduce the interface power of other mobiles in internal and external cells, and analyzed the interference power ratio. Also we have computed BER(Bit Error Rate) by using this interference power ratio and evaluated voice blocking probability(voice packet loss probability) and data transmission delay, according to average data length and average data arrival rate.We have found the CDMA protocol achieves comparatively higher performance for short data length, regardless of data arrival rate. Otherwise, the data transmission delay of D-TDMA protocol is shorter than that of the CDMA protocol for long data message.