• The Journal of Engineering Geology
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• v.26 no.2
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• pp.235-250
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• 2016

In Korea, 70% of the annual rainfall falls in summer, and the number of days of extreme rainfall (over 200 mm) is increasing over time. Because rainfall is the most important trigger of landslides, it is necessary to decide a rainfall threshold for landslide warning and to develop a landslide warning model. This study selected 12 study areas that contained landslides with exactly known triggering times and locations, and also rainfall data. The feasibility of applying a Rainfall Triggering Index (RTI) to Korea is analyzed, and three RTI models that consider different time units for rainfall intensity are compared. The analyses show that the 60-minute RTI model failed to predict landslides in three of the study areas, while both the 30- and 10-minute RTI models gave successful predictions for all of the study areas. Each RTI model showed different mean response times to landslide warning: 4.04 hours in the 60-minute RTI model, 6.08 hours in the 30-minute RTI model, and 9.15 hours in the 10-minute RTI model. Longer response times to landslides were possible using models that considered rainfall intensity for shorter periods of time. Considering the large variations in rainfall intensity that may occur within short periods in Korea, it is possible to increase the accuracy of prediction, and thereby improve the early warning of landslides, using a RTI model that considers rainfall intensity for periods of less than 1 hour.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.217-228
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• 2016

Linux it self does not support real-time. To solve this problem RTiK-Linux was designed to support real-time in the kernel space. However, since the user space does not support real-time, it is not easy to develop application. In this paper, we designed and implemented a RTiK-middleware to support real-time in the user space. RTiK-middleware provides real-time scheduling for user space through signal request period after to register process information with request period using apis on application. To evaluate the performance of the proposed RTiK-middleware, we measured the periods of generated real-time threads using RDTSC instructions, and verified that RTiK-middleware operates correctly within the error ranges of 1ms.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.191-196
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• 2008

This study is a case study for application of the RTI warning model to Korea which was previously developed to predict landslide potential and occurrence time during a rainfall event. The rainfall triggering index (RTI) is defined as the product of the rainfall intensity I (mm/hr) and the effective accumulated rainfall $R_t$ (mm). This index is used to evaluate the landslide and debris-flow occurrence potential at time t during a rainfall event. The upper critical value ($RTI_{UC}$) of RTI and the lower critical value ($RTI_{LC}$) of RTI can be determined by historical rainfall data of a certain area. When the rainfall intensity exceeds the upper critical value, there are high potential to occur land-slides. The analysis result can predict landslide occurrence time of an area during a rainfall event as well as land-slide potential. The result can also be used as an important data to issue early-warning of landslides. In order to apply the RTI warning model to Korea this study analyzed rainfall data and landslides data in Inje county, Gangwon province, Korea from July 13 to July 19, 2006. According to the analysis result, the rainfall intensity exceeded the upper critical value 23 hours ago, 11 hours ago, and 9 hours ago from 11:00 in the morning, July 16. Therefore, landslide warnings would be issued three times for people evacuation for avoiding or reducing hurts and dam-ages from landslides in mountainous areas of Inje.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.79-83
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• 2015

The Response to Intervention(RTI) approaches is the method to help students who are at risk for learning difficulties in advance and provide an appropriate level of intervention. In this article, the characteristics of model RTI were reviewed for students with achievement of below basic proficiency level. We considered RTI as supporting system to document students' progress and its applicability for the general educational setting in Korean school. The tier of RTI make it possible the evidence based individual instruction and counseling, differentiated step-by step approach for students with achievement of below basic proficiency level. In conclusion, RTI can be used as educational tools for dealing with improvement of academic subjects learning, behavioral and emotional problem for students with achievement of below basic proficiency level. For building high quality implementing for RTI it is needed the collaboration of teachers, counselors and learning consultants and related educators.

• Ocean Systems Engineering
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• v.8 no.2
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• pp.167-182
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• 2018

RTI (Rayleigh-Taylor instability) is investigated by a multi-liquid MPS (Moving Particle Semi-implicit) method for both viscous and inviscid flows for various density differences, initial-disturbance amplitudes, viscosities, and surface tensions. The MPS simulation can be continued up to the late stage of high nonlinearity with complicated patterns and its initial developments agree well with the linear theoretical results. According to the relevant linear theory, the difference between inviscid and viscous fluids is the rising velocity at which upward-mushroom-like RTI flow with vortex formation is generated. However, with the developed MPS program, significant differences in both growing patters and developing speeds are observed. Also, more dispersion can be observed in the inviscid case. With larger Atwood (AT) number, stronger RTI flows are developed earlier, as expected, with higher potential-energy differences. With larger initial disturbances, quite different patterns of RTI-development are observed compared to the small-initial-disturbance case. If AT number is small, the surface tension tends to delay and suppress the RTI development when it is sufficiently large. Interestingly, at high AT number, the RTI-suppressions by increased surface tension become less effective.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.54-64
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• 2020

RTiK-Linux is a method to provide real-time performance to Linux, it is controlled by directly accessing hardware registers to implement time tick interrupts. It implemented on x86 Intel and ARM based Exynoss 5422, but it had a disadvantage that it could not be ported to both fragmented other platform environments. In this paper, We change structure of time tick interrupt for improve po rtability so that it can operate on other platforms. We apply high-resolution timers that are independent of hardware, and modify operating structure to task and event to satisfy time determinism. It was confirmed that the improved RTiK-Linux works well in x86 and various ARM AP environments.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.55-56
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• 2012

과학기술이 발전함에 따라 신무기들의 기술 집약도가 발전하여 개체 하나하나의 단가와 가치가 상승하고 있다. 이렇게 개발된 무기를 사용하기 앞서 수락시험을 위해 점검장비를 사용하고 있다. 이러한 점검장비는 신무기의 성능 및 기능의 검증을 위해 데이터의 수집 및 처리를 하기 위한 실시간성을 필요로 한다. 그러나 점검장비에서 많이 사용되고 있는 범용 운영체제인 윈도우의 경우 실시간성을 지원하지 못하는 문제점을 가지고 있다. 따라서 윈도우에 실시간성을 제공하기 위한 상용솔루션인 RTX 및 INtime을 사용하여 실시간성을 제공해야 한다. 하지만 RTX와 INtime은 고가의 구입비 및 경상 사용료로 인해 개발 비용을 증가시키는 문제점을 가지고 있다. 이를 해결하기 위해 멀티코어 기반 윈도우 환경의 점검장비에 실시간성을 지원하기 위한 실시간 이식 커널(RTiK-MP)을 개발하였다. 본 논문에서는 개발된 RTiK-MP를 다양한 분야에 적용시키고, 개발자에게 보다 나은 편의성을 제공하기 위해 Export Driver를 통한 RTiK-MP 접근 방안에 대한 연구를 하였다.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.45-53
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• 2011

According to the necessity of measuring equipments for advanced military systems, real-time characteristics such as time determinism and execution accuracy pursuing low-latencies have become very important. With this reason, the market demand for real-time features in the general purpose operating system such as Linux has been enlarging. To meet these requirements, RTLinux and RTAI has been developed as dual-kernels based on Linux. However, developers should use assembler languages to facilitate real-time in RT-Linux, it is very difficult to deal with it. RTAI has disadvantage that it only provides soft real-time. To solve these problems, RTiK-Linux was developed. In this paper, we propose a new dual-kernel with hard real-time capabilities in Linux, called RTiK-Linux(Real-Time implemented Kernel for Linux). We first introduce related researches and then describe the design methodologies to guarantee the resolution which almost accords with the timer settings. Finally, we present the results of experimental measurements and analyze them in order to validate and evaluate the proposed RTiK-Linux.

• Fire Science and Engineering
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• v.34 no.3
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• pp.35-42
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• 2020

The accurate prediction of fire detector activation time is required to ensure the reliability of fire modeling during the safety assessment of performance-based fire safety design. The main objective of this study is to determine the activation temperature and the response time index (RTI) of a fixed heat detector, which are the main input factors of a fixed-temperature heat detector applied to the fire dynamics simulator (FDS), a typical fire model. Therefore, a fire detector evaluator, which is a fire detector experimental apparatus, was applied, and 10 types of domestic fixed-temperature heat detectors were selected through a product recognition survey. It was found that there were significant differences in the activation temperature and RTI among the detectors. Additionally, the detector activation time of the FDS with the measured DB can be predicted more accurately. Finally, the DB of the activation temperature and RTI of the fixed-temperature heat detectors with reliability was provided.

• International Journal of Contents
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• v.16 no.2
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• pp.41-50
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• 2020

This paper presents Reflectance Transformation Imaging (RTI) as a tool to support the study of paintings and authentication. Manufacturing techniques of the artist are reviewed through the comparison between liberal perspectives and digital imaging techniques. In this study, RTI was applied to focus on the detailed textural information of eight paintings by Korean artist Lee Ji-ho. The RTI result visualizes shallow reliefs of brush strokes and different mediums on the surface technically enhanced through imaging filters, and these morphological textures on the surface act as a key factor in understanding the characteristics of the artist. The surface morphology and art criticism work as qualitative indicators to analyze the change of artistic techniques through time, and the usage of different mediums. The results of this study confirm that the RTI technique can be used as an analysis device in the study of paintings.