• Journal of the Korean Geotechnical Society
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• v.26 no.9
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• pp.71-74
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• 2010

During construction of deep foundation in soft rock under varying soil properties, it is essential to locate the rock stratum, especially when drilling with slurry. When slurry is used for drilling, the bottom of the borehole cannot be seen, thereafter soil cuttings cannot be differentiated from soft rock cuttings. A new static rock penetrometer, known as Rock Penetrometer was developed during this study. It could be a simple mechanical device that is attached to the bottom of a Kelly bar which is used to attach drilling tools such as augers and core barrels while drilling. After its calibration in the laboratory, the performance of the static rock penetrometer was verified in the several field test sites.

• East Asian Journal of Business Economics (EAJBE)
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• v.11 no.2
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• pp.59-70
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• 2023

Purpose - The hospitality industry has experienced significant transformations in recent years, primarily driven by advancements in technology and changes in consumer behavior. The worldwide COVID-19 epidemic has intensified a trend of hotel guests increasingly relying on meal delivery applications. Considering the recent COVID-19 pandemic, this study sets out to investigate how hotel guests have been using food delivery apps before and during the outbreak. Research design, data, and methodology - This study utilizes a systematic literature review as its research design. A systematic literature review is a methodical, well-structured procedure for locating, analyzing, and synthesizing pertinent research articles. Result - The findings shed light on four main aspects: convenience and accessibility, safety and hygiene assurance, personalization and customization, and local exploration and cultural immersion. These findings provide valuable insights into the evolving preferences and behaviors of hotel guests in utilizing food delivery apps, particularly in the context of the COVID-19 pandemic. Conclusion - This study has contributed to the understanding of the changing role of food delivery apps among hotel guests. By recognizing the evolving dynamics and leveraging the opportunities presented by food delivery apps, hotels can adapt to meet guest expectations, enhance customer satisfaction, and thrive in the ever-changing landscape of the hospitality industry.

• Smart Structures and Systems
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• v.31 no.6
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• pp.573-583
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• 2023

Although unmanned aerial vehicles have been used to overcome the limited accessibility of human-based visual inspection, unresolved issues still remain. Onsite inspectors face difficulty finding previously detected damage locations and tracking their status onsite. For example, an inspector still marks the damage location on a target structure with chalk or drawings while comparing the current status of existing damages to their previous status, as documented onsite. In this study, an augmented-reality-based structural inspection system with onsite damage information marking was developed to enhance the convenience of inspectors. The developed system detects structural damage, creates a holographic marker with damage information on the actual physical damage, and displays the marker onsite via an augmented reality headset. Because inspectors can view a marker with damage information in real time on the display, they can easily identify where the previous damage has occurred and whether the size of the damage is increasing. The performance of the developed system was validated through a field test, demonstrating that the system can enhance convenience by accelerating the inspector's essential tasks such as detecting damages, measuring their size, manually recording their information, and locating previous damages.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.126-129
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• 2021

The existing drainage facility management system is not systematically computerized, and it is difficult to manage each drainage facility on-site due to insufficient information and location management. Currently, in the current drainage system management, repair technicians recognize the information of the drainage facility by recognizing the QR code at the site. These methods have difficulty locating QR codes in the field, and the problem is that they incur additional maintenance costs due to loss and breakage of QR code attachments. The GPS-based drainage management system proposed in this paper stores and manages each drainage facility's data including GPS information, allowing applications to use the location and information of drainage facilities based on user location data.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.114-114
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• 2020

Water contamination in a water distribution network (WDN) is harmful since it directly induces the consumer's health problem and suspends water service in a wide area. Actions need to be taken rapidly to countermeasure a contamination event. A contaminant source ident ification (CSI) is an important initial step to mitigate the harmful event. Here, a CSI approach focused on determining the contaminant intrusion possible location and time (PLoT) is introduced. One of the methods to discover the PLoT is an inverse calculation to connect all the paths leading to the report specification of a sensor. A filtering procedure is then applied to narrow down the PLoT using the results from individual sensors. First, we spatially reduce the suspect intrusion points by locating the highly suspicious nodes that have similar intrusion time. Then, we narrow the possible intrusion time by matching the suspicious intrusion time to the reported information. Finally, a likelihood-score is estimated for each suspect. Another important aspect that needs to be considered in CSI is that there are inherent uncertainties, such as the variations in user demand and inaccuracy of sensor data. The uncertainties can lead to overlooking the real intrusion point and time. To reflect the uncertainties in the CSI process, the Monte-Carlo Simulation (MCS) is conducted to explore the ranges of PLoT. By analyzing all the accumulated scores through the random sets, a spread of contaminant intrusion PLoT can then be identified in the network.

• Geomechanics and Engineering
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• v.34 no.3
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• pp.285-301
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• 2023

During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the strength of discontinuities and anchor bond strength by applying different optimization techniques for finding the critical failure surface. Even though the deterministic safety factor value is close to unity, the probability of failure is governed by variability of shear strength of anisotropic planes and optimization method used for locating the critical sliding surface. The Cuckoo search technique produces higher failure probabilities compared to the others. Depending on the assigned statistical distribution of input parameters, various performance functions of the factor of safety are obtained. The probability of failure is insensitive to the variation of bond strength. Different sampling techniques should yield similar results considering that the sufficient number of safety factor evaluations is chosen to achieve converged solution.

• Smart Media Journal
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• v.11 no.7
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• pp.94-103
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• 2022

Weeds bring disadvantages to crops since they can damage them, and a clean treatment with less pollution and contamination should be developed. Artificial intelligence gives new hope to agriculture to achieve smart farming. This study delivers an automated weeds growth point detection using deep learning. This study proposes a combination of semantic graphics for generating data annotation and U-Net with pre-trained deep learning as a backbone for locating the growth point of the weeds on the given field scene. The dataset was collected from an actual field. We measured the intersection over union, f1-score, precision, and recall to evaluate our method. Moreover, Mobilenet V2 was chosen as the backbone and compared with Resnet 34. The results showed that the proposed method was accurate enough to detect the growth point and handle the brightness variation. The best performance was achieved by Mobilenet V2 as a backbone with IoU 96.81%, precision 97.77%, recall 98.97%, and f1-score 97.30%.

• The Journal of Industrial Distribution & Business
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• v.14 no.12
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• pp.33-41
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• 2023

Purpose: This study's primary goal is to investigate and evaluate the critical contributions made by industrial-organizational psychologists to raising worker job satisfaction. The study aims to offer insights that can enhance workplace environments, improve organizational processes, and increase employees' general well-being by looking at the particular contributions made by this field. Research design, data and methodology: The study design, data collection strategies using the literature content analysis allow for a thorough analysis and synthesis of the body of knowledge about industrial-organizational psychologists' contributions to improving worker job satisfaction. This method entails a sequential procedure that includes formulating research questions and locating pertinent studies. Results: Numerous previous works have indicated that industrial-organizational psychologists are essential in determining how an organization is run and how satisfied its workforce is with their jobs. The four major roles (Job Design, Leadership, Workplace Culture, and Employee Development) that were found after a thorough analysis of the body of current literature are presented in this section. Conclusions: In sum, the roles found in this study provide organizations with a framework for creating work environments that prioritize the well-being and overall growth of the people who make up the organization while also helping them negotiate the complexity of the modern workplace.

• Smart Structures and Systems
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• v.32 no.4
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• pp.195-205
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• 2023

The contact acoustic emission (AE) monitoring system is time-consuming and costly for monitoring concrete structures in large scope, in addition, the great difference in acoustic impedance between air and concrete makes the detection process inconvenient. In this work, we broaden the conventional AE source localization method for concrete to the non-contact (air-coupled) micro-electromechanical system (MEMS) microphones array, which collects the energy-rich leaky Rayleigh waves, instead of the relatively weak P-wave. Finite element method was used for the numerical simulations, it is shown that the propagation velocity of leaky Rayleigh waves traveling along the air-concrete interface agrees with the corresponding theoretical properties of Lamb wave modes in an infinite concrete slab. This structures the basis for implementing a non-contact AE source location approach. Based on the experience gained from numerical studies, experimental studies on the proposed air-coupled AE source location in concrete slabs are carried out. Finally, it is shown that the locating map of AE source can be determined using the proposed system, and the accuracy is sufficient for most field monitoring applications on large plate-like concrete structures, such as tunnel lining and bridge deck.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.852-862
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• 2020

Interventional radiology (IR) embolization requires image guidance to steer catheters to the site of bleeding, where embolic agents such as Gelfoam or coils are administered to stem blood flow. In addition to treating iatrogenic trauma, embolization is suitable for injuries precluding surgery such as blush-bleeding of the liver or kidney and for locating and treating intimal blood vessel tears. However, during hospital off-hours (such as nights and holidays), experienced IR personnel are not always available. In such situations, there is a dire need to build a coordinated IR team to treat seriously injured patients rapidly and reliably. This article reviews the current principles and techniques used in IR such as virtual fluoroscopy and their usefulness, and makes a convincing case for emergency IR.