• Journal of Construction Engineering and Project Management
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• v.4 no.4
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• pp.1-8
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• 2014

The broad aim of this paper is to provide a detailed understanding of the post-war problems associated with materials for reconstruction in Libya, and to identify key problems and obstructions. Theoretical and empirical studies are being conducted in Libya. The theoretical study focuses on materials for construction and the key issues such as sources, transport and storage of materials, as well as their impact on the national economy, the nation's socio-economic development and the environment. This empirical study employed questionnaires, observations and a series of interviews with researchers, academics, suppliers and manufacturers, supported by the researcher's three decades of experience of working in the construction industry and its associated processes and operations. The empirical study illustrated that materials for post-disaster reconstruction in Libya suffer from external problems related to policies and decision-making in terms of availability of materials, fluctuation of prices of materials, specifications, building codes, legislation and regulations, and internal problems related to the construction and building material's key players: construction companies, consultancy firms, manufacturers and suppliers.

• Korean Journal of Remote Sensing
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• v.24 no.1
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• pp.79-89
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• 2008

Irregular temporal sampling is a common feature of geophysical and biological time series in remote sensing. This study proposes an on-line system for reconstructing observation image series contaminated by noises resulted from mechanical problems or sensing environmental condition. There is also a high likelihood that during the data acquisition periods the target site corresponding to any given pixel may be covered by fog or cloud, thereby resulting in bad or missing observation. The surface parameters associated with the land are usually dependent on the climate, and many physical processes that are displayed in the image sensed from the land then exhibit temporal variation with seasonal periodicity. A feedback system proposed in this study reconstructs a sequence of images remotely sensed from the land surface having the physical processes with seasonal periodicity. The harmonic model is used to track seasonal variation through time, and a Gibbs random field (GRF) is used to represent the spatial dependency of digital image processes. The experimental results of this simulation study show the potentiality of the proposed system to reconstruct the image series observed by imperfect sensing technology from the environment which are frequently influenced by bad weather. This study provides fundamental information on the elements of the proposed system for right usage in application.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.13-25
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• 2017

To reconstruct the paleo-temperature quantitatively and to overcome limitation of traditional qualitative pollen analysis, this study was performed pollen analysis using the modern surface soil at Yulha-dong, Gimhae-si of southeastern part of Korean peninsula. Canonical Correspondence Analysis(CCA) was done to identify the most important environment variable about composition of modern surface pollen sample. Also, Weighted Average-Partial Least Square(WA-PLS) was analyzed to obtain modern surface pollen-temperature transfer function. The transfer function was applied to the results of qualitative fossil pollen analysis at Yulha-dong, Gimhae-si, Sampyung-ri, Ulsan-si and Taewha-dong, Ulsan-si. Therefore, the paleo-temperature was reconstructed during the Holocene since 6,200 yr BP. According to the results of the research, it is $1{\sim}2^{\circ}C$ lower than the current average annual temperature at the study area in 6,200 yr BP, since then it increased to the same level to the current temperature and decreased again until 2,600 yr BP. From the 2,600 yr BP, the temperature was fluctuated to the present.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.161-168
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• 2019

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

• Ocean Systems Engineering
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• v.13 no.2
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• pp.195-224
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• 2023

This paper proposes a method for the acoustic imaging wherein the traditional requirement of the relative movement between the transmitter and target is overcome. This is facilitated through the beamforming acoustic array in the transmitter, in which the target is illuminated by the array at various azimuth and elevation angles without the physical movement of the acoustic array. The concept of beam steering of the acoustic array facilitates the formation of the beam at desired angular positions of azimuth and elevation angles. This paper substantiates that the combination of illumination of the target from different azimuth and elevation angles with respect to the transmitter (through the beam steering of beam forming acoustic array) and the beam steering at multiple frequencies (through SF) results in enhanced reconstruction of images of the target in the underwater scenario. This paper also demonstrates the possibility of reconstruction of the image of a target in underwater without invoking the traditional algorithms of Digital Image Processing (DIP). This paper comprehensively and succinctly presents all the empirical formulae required for modelling the acoustic medium and the target to facilitate the reader with a comprehensive summary document incorporating the various parameters of multi-disciplinary nature.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.1
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• pp.29-37
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• 2020

Work to improve network throughput has been focused on network coding as the utilization of IoT-based application services increases and network usage increases rapidly. In network coding, nodes transform packets received from neighboring nodes into a combination of encoded packets for transmission and decoding at the destination. This scheme is based on trust among nodes, but in the IoT environment where nodes are free to join, a malicious node can fabricate the packet if it legally participates in the configuration. It is difficult to identify the authenticity of the encoded packet since the packet received at destination is not a single source but a combination of packets generated by several nodes. In this paper, we propose a method to detect "look-like-valid" packets that have been attacked and disguised in packets received at destination, and to identify valid messages in the reconstructions. This method shows that network coding performance is significantly improved because the destination can reconstruct a valid message with only received packets without retransmission with a high probability, despite the presence of disguised packets.

• Convergence Security Journal
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• v.18 no.5_1
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• pp.19-24
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• 2018

For a long time now, general-purpose processors have provided dedicated hardware / software tracing modules to provide developers with tools to fix bugs. A hardware tracer generates its enormous data into a log that is used for both performance analysis and debugging. Processor Trace (PT) is a new hardware-based tracing feature for Intel CPUs that traces branches executing on the CPU, which allows the reconstruction of the control flow of all executed code with minimal labor. Hardware tracer has been integrated into the operating system, which allows tight integration with its profiling and debugging mechanisms. However, in the Windows environment, existing studies related to PT focused on decoding only one flow in sequence. In this paper, we propose an extended PT decoder structure that provides basic data for real-time trace and malicious code detection using the functions provided by PT in Windows environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.127-134
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• 2021

In this study, an anomaly detection (AD) algorithm was implemented to detect the failure of a marine air compressor. A lab-scale experiment was designed to produce fault datasets (time-series electric current measurements) for 10 failure modes of the air compressor. The results demonstrated that the temporal pattern of the datasets showed periodicity with a different period, depending on the failure mode. An AD model with a convolutional autoencoder was developed and trained based on a normal operation dataset. The reconstruction error was used as the threshold for AD. The reconstruction error was noted to be dependent on the AD model and hyperparameter tuning. The AD model was applied to the synthetic dataset, which comprised both normal and abnormal conditions of the air compressor for validation. The AD model exhibited good detection performance on anomalies showing periodicity but poor performance on anomalies resulting from subtle load changes in the motor.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.11-16
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• 2023

The technology of 3D reconstruction, primarily relying on point cloud data, is essential for digitizing objects or spaces. This paper aims to utilize reinforcement learning to achieve the acquisition of point clouds in a given environment. To accomplish this, a simulation environment is constructed using Unity, and reinforcement learning is implemented using the Unity package known as ML-Agents. The process of point cloud acquisition involves initially setting a goal and calculating a traversable path around the goal. The traversal path is segmented at regular intervals, with rewards assigned at each step. To prevent the agent from deviating from the path, rewards are increased. Additionally, rewards are granted each time the agent fixates on the goal during traversal, facilitating the learning of optimal points for point cloud acquisition at each traversal step. Experimental results demonstrate that despite the variability in traversal paths, the approach enables the acquisition of relatively accurate point clouds.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.5
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• pp.915-925
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• 2024

As non-face-to-face work increases due to the COVID-19 pandemic, companies have introduced collaboration tools to perform work without spatial constraints. The rapidly growing collaboration tool market continues to show high utilization rates even after the endemic due to the increase in demand for hybrid work that combines face-to-face and non-face-to-face work. The use of collaboration tools increases work efficiency, facilitates smooth collaboration, and increases data integration, generating various data. However, at the same time, it also increases the risk of exposure of corporate confidential information due to the possibility of external access by internal users. In response to this, an analysis method is needed to collect and acquire data during digital investigations targeting collaboration tools. In this paper, we identified local artifacts targeting JANDI, a collaboration tool in a Windows environment, and explained how to collect and analyze data through API reconstruction. Finally, we presented a digital forensic utilization method through scenario and chat room reconstruction.