• International conference on construction engineering and project management
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• 2020.12a
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• pp.463-481
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• 2020

Cutter suction dredgers (CSDs) are widely used in various dredging constructions such as channel excavation, wharf construction, and reef construction. During a CSD construction, the main operation is to control the swing speed of cutter to keep the slurry concentration in a proper range. However, the slurry concentration cannot be monitored in real-time, i.e., there is a "time-lag effect" in the log of slurry concentration, making it difficult for operators to make the optimal decision on controlling. Concerning this issue, a solution scheme that using real-time monitored indicators to predict current slurry concentration is proposed in this research. The characteristics of the CSD monitoring data are first studied, and a set of preprocessing methods are presented. Then we put forward the concept of "index class" to select the important indices. Finally, an ensemble learning algorithm is set up to fit the relationship between the slurry concentration and the indices of the index classes. In the experiment, log data over seven days of a practical dredging construction is collected. For comparison, the Deep Neural Network (DNN), Long Short Time Memory (LSTM), Support Vector Machine (SVM), Random Forest (RF), Gradient Boosting Decision Tree (GBDT), and the Bayesian Ridge algorithm are tried. The results show that our method has the best performance with an R² of 0.886 and a mean square error (MSE) of 5.538. This research provides an effective way for real-time predicting the slurry concentration of CSDs and can help to improve the stationarity and production efficiency of dredging construction.

• Journal of Korean Society of Archives and Records Management
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• v.23 no.4
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• pp.1-24
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• 2023

At present, domestic archives within the realm of performing arts predominantly focus on recording through videos, yet they often lack comprehensive documentation of crucial production processes and content services. Recognizing the contemporary significance of archival content services, this study analyzes the archival content within the national performing arts archives websites of the United Kingdom and the United States, serving as international benchmarks. The findings extrapolate insights and implications to propose enhancements for the Museum of Performing Arts in the National Theater of Korea. The analysis focused mainly on the missions and visions on the websites, examining 107 contents from the UK National Theater, 27 from the United States, and 9 from Korea. The suggested improvements encompass clarifying target users and execution tasks in the mission and vision statements, fostering expert collaborations, incorporating preview features, curating content with a single theme, and organizing a comprehensive list on the National Theater's YouTube channel.

• Information Systems Review
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• v.21 no.1
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• pp.61-90
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• 2019

From the digital perspective, customer journey and customer experience management are emerging as important issues for companies. While digital customer experience has become more important due to the recent surge in online sales of the home appliance products, customers' experience in online is not differentiated as offline-focused traditional methods are maintained. This study aims to analyze the characteristics and mutual influences of customer experiences at each stage of online purchase journey, and to explore the effects on the product repurchase intention, focusing on online purchasers of home appliance which are high-involvement products. As a result, both cognitive and affective experiences of the research phase directly affect satisfaction, whereas affective experience at the purchasing stage indicated indirect effects through cognitive experience. The experience of the research phase positively affects the next phase, the purchasing experience, and the experience of the purchasing phase leads to the intention to repurchase the product. However, it is also found that, depending on the choice of online channels, the experience of research phase may affect the product repurchase intention than the purchase experience.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.552-558
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• 2024

In dispersion management, which involves additionally inserting a dispersion compensation fiber of an appropriate length to eliminate or reduce the chromatic dispersion of a single-mode fiber, determining the form of the dispersion map, which is the cumulative dispersion profile according to the transmission distance, is the most basic and important. In this paper, the various symmetric dispersion map based on trapezoids applied to dispersion-managed links combined with mid-span spectral inversion (MSSI), which compensates for the distortion caused by Kerr nonlinear effects through optical phase conjugation in the middle of the entire transmission link are proposed, and the effect of each dispersion map on distortion compensation of wavelength division multiplexed (WDM) signals is analyzed. Although the degree of compensation varies depending on the factors that determine the detailed shape of the proposed trapezoid-shaped dispersion map and RDPS (residual dispersion per span), overall, it was confirmed that distortion compensation for signals with a small extinction ratio was more effective than distortion compensation for WDM channel signals with a large extinction ratio.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1293-1293
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• 2024

Virtual reality (VR) is increasingly utilized in the construction industry for diverse applications. Immersive virtual reality (IVR) offers practical experiences and educational opportunities for workers, enhancing productivity and safety. Efforts to optimize IVR involve analyzing biometric responses to monitor concentration, assess learning efficiency, and deliver personalized content. However, IVR faces challenges such as high production costs and prolonged production periods. Additionally, integrating biometric response recording into IVR experiences requires separate modules, further extending production timelines. To address these challenges, an integrated platform is necessary to streamline IVR production, user experience, and biometric response setup and recording. This study introduces such a platform designed to enhance the efficacy of IVR experiences through real-time biometric response analysis. The proposed platform comprises three main processes: (i) IVR content production using Unity; (ii) biometric response definition; and (iii) IVR content experience accompanied by generated logs for biometric responses. Firstly, IVR content production using Unity involves the development of IVR environments and scenarios. The platform incorporates diverse 3D models, including urban landscapes, building elements, and furniture, as the basis for IVR environments. Scenarios are constructed by integrating events into these environments, triggered by conditions such as reaching specific locations, the passage of time, or user interactions. Upon event activation, participants are presented with description UIs, quiz UIs, or route guidance, facilitating engagement and progression through interaction. Secondly, biometric responses encompass eye tracking and EEG. Eye tracking captures pupil diameter and fixation status on Areas of Interest (AOI), defined during IVR content production. EEG recording options include signals from each channel by default, as well as frequency-specific signals and EEG metrics such as attention, stress, fatigue, valence, and arousal. The platform supports the addition of new EEG metrics, enhancing customization and recording capabilities. Lastly, IVR content can be experienced alongside generated logs for biometric responses. The dataset enables monitoring and evaluation of participants' learning performance during IVR experiences, with the potential to enhance worker safety and productivity through immersive practical training and education.

• Asia pacific journal of information systems
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• v.18 no.1
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• pp.1-23
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• 2008

As managing customer relationship gets more important, companies are strengthening information service using multi-channels to their customers as a part of their customer relationship management (CRM) initiatives. It means companies are now accepting such information services not as simple information -delivering tools, but as strategic initiatives for acquiring and maintaining customer loyalty. In this paper, we attempt to validate whether or not such various information services would impact on organizational performance in terms of CRM strategy. More specifically, our research objective is to answer the next three questions: first, how to construct the instruments to measure not information quality but information service quality?; second, which attributes of information service quality can influence corporate image and customer loyalty?; finally, does each information service type have unique characteristics compared with others in terms of influencing corporate image and customer loyalty? With respect to providing answers to those questions, the previous studies had been limited in that those studies failed to consider the variety of types of information service or restricted the quality of information service to information quality. An appropriate research model answering the above questions should consider the fact that most companies are utilizing multi channels for their information services, and include the recent strategic information service such as customer online community. Moreover, since corporate information service could be regarded as a type of products or services delivered to customer, it is necessary to adopt the criteria for assessing customer's perceived value when to measure the quality of information service. Therefore, considering both multi-channels and multi-traits may enable us to tell the detailed causal routes showing which quality attributes of which information service would affect corporate image and customer loyalty. As information service channels, we include not only homepage and DM (direct mail), which are the most frequently applied information service channels, but also online community, which is getting more strategic importance in recent years. With respect to information service quality, we abstract information quality, convenience of information service, and timeliness of information service through a wide range of relevant literature reviews. As our dependant variables, we consider corporate image and customer loyalty that both of them are the critical determinants of organizational performance, and also attempt to grasp the relationship between the two constructs. We conducted a huge online survey at the homepage of one of representative dairy companies in Korea, and gathered 367 valid samples from 407 customers. The reliability and validity of our measurements were tested by using Cronbach's alpha coefficient and principal factor analysis respectively, and seven hypotheses were tested through performing correlation test and multiple regression analysis. The results from data analysis demonstrated that timeliness and convenience of homepage have positive effects on both corporate image and customer loyalty. In terms of DM, its' information quality was represented to influence both corporate image and customer loyalty, but we found its' convenience have a positive effect only on corporate image. With respect to online community, we found its timeliness contribute significantly both to corporate image and customer loyalty. Finally, as we expected, corporate image was revealed to provide a great influence to customer loyalty. This paper provides several academic and practical implications. Firstly, we think our research reinforces CRM literatures by developing the instruments for measuring information service quality. The previous relevant studies have mainly depended on the measurements of information quality or service quality which were developed independently. Secondly, the fact that we conducted our research in a real situation may enable academics and practitioners to understand the effects of information services more clearly. Finally, since our study involved three different types of information service which are most frequently applied in recent years, the results from our study might provide operational guidelines to the companies that are delivering their customers information by multi-channel. In other words, since we found that, in terms of customer loyalty, the key areas would be different from each other according to the types of information services, our analysis would help to make decisions such as selecting strengthening points or allocating resources by information service channels.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.251-257
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• 2014

In u-Healthcare environment, large amounts of important vital information is processed through M2M(Machine to Machine). M2M is configured by wireless networks and has several problems for limited bandwidth and low reliability. Therefore, in this paper is proposed a method called uHLZW(u-Healthcare LZW) to improve channel efficiency to solve such problem. uHLZW algorithm has high compression ratio for vital data. The results showed that the average compression ratio of uHLZW got from 1.6 times to 4.0 times better than existing methods(Huffman and LZW compression).

• Environmental Engineering Research
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• v.12 no.5
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• pp.211-217
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• 2007

Polycyclic aromatic hydrocarbon growth from cyclopentadiene (CPD) pyrolysis was investigated using a laminar flow reactor operating in a temperature range of 600 to $950^{\circ}c$. Major products from CPD pyrolysis are benzene, indene and naphthalene. Formation of observed products from CPD is explained as follows. Addition of the cyclopentadienyl radical to a CPD $\pi$-bond produces a resonance-stabilized radical, which further reacts by one of three unimolecular channels: intramolecular addition, C-H bond $\beta$-scission, or C-C bond $\beta$-scission. The intramolecular addition pathway produces a 7-norbornenyl radical, which then decomposes to indene. Decomposition by C-H bond $\beta$-scission produces a biaryl intermediate, which then undergoes a ring fusion sequence that has been proposed for dihydrofulvalene-to-naphthalene conversion. In this study, we propose C-C bond $\beta$-scission pathway as an alternative reaction channel to naphthalene from CPD. As preliminary computational analysis, Parametric Method 3 (PM3) molecular calculation suggests that intramolecular addition to form indene is favored at low temperatures and C-C bond $\beta$-scission leading to naphthalene is predominant at high temperatures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.179-185
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• 2010

In ubiquitous society, there have been increasing demands on safety and security issues with infrastructures and services based on wireless technology. In this paper, we first introduce our own developed technology Binary CDMA to meet those demands. Then we present a wireless A/V surveillance system based on the Binary CDMA technology. The implemented wireless A/V surveillance system is composed of wireless terminals, wireless multiple channel processors, and an A/V management server, and the system gives a hint that the Binary CDMA technology can be adopted in practical ubiquitous systems to handle safety and security issues.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.179-184
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• 2012

A car accident on a highway occurs a chain-reaction collision because of a vehicle's fast velocity. In order to prevent it, the accident vehicle should broadcast a safe message to its neighbors. If there are many neighbor nodes, a frame collision probability is high. To solve this, it was proposed for a system as a previous study to send a safe message without frame-collision using separating channels. However, the separation of multiple channels make feasibility low because of increasing hardware's development cost and complexity. In this paper, we proposes a TDMA-based MAC protocol using a single channel. As a result, we show the frame reception success rate of our protocol was almost the same as the previous protocol.