• The Korean Journal of Pesticide Science
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• v.9 no.2
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• pp.140-145
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• 2005

Quantitative Structure Activity Relationship (QSAR) assumes the relatedness between physical property and biological activity. However, activity data measured at single concentration such as percent activity have not been used extensively for modeling purpose. This probably comes from the fact that these values are qualitative instead of quantitative. To utilize percent activity data for molecular modeling, we classified the whole data into two classes. One class represents the active while the other signifies the inactive. The percent activity data of ${\beta}$-Ketoacetoanilides measured for TLB (Tomato Late Blight) were investigated. CoMFA (Comparative Molecular Field Analysis) was used as a discriminant function. Using CoMFA provides 3D (three dimensional) information, which is crucial for chemical insight. It can also serve as a predictive model. The resultant model classified the given data correctly (98%). When LOO (leave-one-out) crossvalidation procedure was applied, the classification accuracy was 69%. Therefore two class approximation of percent activity data with CoMFA can be utilized to understand the relationship between chemical structure and biological activity and design subsequent chemical analogs.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.405-415
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• 2000

This study was carried out to understand the formation of acid mine drainage (AMD) by pyrophyllite (so-called Napseok)-rainwater interaction (weathering), dispersion patterns of heavy metals, and patterns of mixing with non-polluted water in the Tongnae pyrophyllite mine. Based on the mass balance and reaction path modeling, using both the geochemistry of water and occurrence of the secondary minerals (weathering products), the geochemical evolution of AMD was simulated by computer code of SOLVEQ and CHILLER. It shows that the pH of stream water is from 6.2 to 7.3 upstream of the Tongnae mine. Close to the mine, the pH decreases to 2. Despite being diluted with non-polluted tributaries, the acidity of mine drainage water maintains as far as downstream. The results of modeling of water-rock interaction show that the activity of hydrogen ion increases (pH decreases), the goncentration of ${HCO_3}^-$ decreases associated with increasing $H^+$ activity, as the reaction is processing. The concentration of ${SO_4}^{2-}$first increases minutely, but later increases rapidly as pH drops below 4.3. The concentrations of cations and heavy metals are controlled by the dissolution of reactants and re-dissolution of derived species (weathering products) according to the pH. The continuous adding of reactive minerals, namely the progressively larger degrees of water-rock interaction, causes the formation of secondary minerals in the following sequence; goethite, then Mn-oxides, then boehmite, then kaolinite, then Ca-nontronite, then Mgnontronite, and finally chalcedony. The results of reaction path modeling agree well with the field data, and offer useful information on the geochemical evolution of AMD. The results of reaction path modeling on the formation of AMD offer useful information for the estimation and the appraisal of pollution caused by water-rock interaction as geological environments. And also, the ones can be used as data for the choice of appropriate remediation technique for AMD.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3328-3349
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• 2020

With rapid development of ubiquitous computing and location-based services (LBSs), human trajectory data and associated activities are increasingly easily recorded. Inappropriately publishing trajectory data may leak users' privacy. Therefore, we study publishing trajectory data while preserving privacy, denoted privacy-preserving activity trajectories publishing (PPATP). We propose S-PPATP to solve this problem. S-PPATP comprises three steps: modeling, algorithm design and algorithm adjustment. During modeling, two user models describe users' behaviors: one based on a Markov chain and the other based on the hidden Markov model. We assume a potential adversary who intends to infer users' privacy, defined as a set of sensitive information. An adversary model is then proposed to define the adversary's background knowledge and inference method. Additionally, privacy requirements and a data quality metric are defined for assessment. During algorithm design, we propose two publishing algorithms corresponding to the user models and prove that both algorithms satisfy the privacy requirement. Then, we perform a comparative analysis on utility, efficiency and speedup techniques. Finally, we evaluate our algorithms through experiments on several datasets. The experiment results verify that our proposed algorithms preserve users' privay. We also test utility and discuss the privacy-utility tradeoff that real-world data publishers may face.

• Geomechanics and Engineering
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• v.31 no.3
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• pp.319-328
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• 2022

Ensuring the integrity of a country's infrastructure is necessary to protect surrounding communities in case of disaster. Embankment dam systems across the US are an essential component of infrastructure, referred to as lifeline structures. Embankment dams are crucial to the survival of life and if these structures were to fail, it is imperative that states be prepared. Southern California is particularly concerned with the stability of embankment dams due to the frequent seismic activity that occurs in the state. The purpose of this study was to create a numerical model of an existing embankment dam simulated under seismic loads using previously recorded data. The embankment dam that was studied in Los Angeles, California was outfitted with accelerometers provided by the California Strong Motion Instrumentation Program that have recorded strong motion data for decades and was processed by the Center for Engineering Strong Motion Data to be used in future engineering applications. The accelerometer data was then used to verify the numerical model that was created using finite element modeling software RS2. The results from this study showed Puddingstone Dam's simulated response was consistent with that experienced during previous earthquakes and therefore validated the predicted behavior from the numerical model. The study also identified areas of weakness and instability on the dam that posed the greatest risk for its failure. Following this study, the numerical model can now be used to predict the dam's response to future earthquakes, develop plans for its remediation, and for emergency response in case of disaster.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.393-399
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• 2009

This paper introduces an automated tool named Advanced Stochastic Schedule Simulation System (AS4). The system automatically integrates CPM schedule data exported from Primavera Project Planner (P3) and historical activity duration data obtained from a project data warehouse, computes the best fit probability distribution functions (PDFs) of historical activity durations, assigns the PDFs identified to respective activities, computes the optimum number of simulation runs, simulates the schedule network for the optimum number of simulation runs, and estimates the best fit PDF of project completion times (PCTs). AS4 improves the reliability of simulation-based scheduling by effectively dealing with the uncertainties of the activities' durations, increases the usability of the schedule data obtained from commercial CPM software, and effectively handles the variability of the PCTs by finding the best fit PDF of PCTs. It is designed as an easy-to-use computer tool programmed in MATLAB. AS4 encourages the use of simulation-based scheduling because it is simple to use, it simplifies the tedious and burdensome process involved in finding the PDFs of the many activities' durations and in assigning the PDFs to the many activities of a new network under modeling, and it does away with the normality assumptions used by most simulation-based scheduling systems in modeling PCTs.

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.81-87
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• 2007

In this study digital human models of ship construction tasks using modeling & simulation were constructed and human models' activities through human activity analysis were evaluated. Human Factors experts analyzed the actual workers' tasks using the same technique used in human activity analysis at the same time. The main objective of this study is to check a possibility of applying digital human modeling technique to ship construction tasks that are mostly non-standardized(not uniformed) whereas most applications of digital human modeling technique have been applied to standardized tasks. We evaluated postures of both real workers and digital humans by RULA. It turned out that the final scores of RULA evaluation on real workers are the same as the RULA scores for digital humans. However, there were differences of RULA detail scores between real workers and digital humans in the several processes related with the wrist twist and deviations. Those differences are considered to be resulted from the error in the on-site measuring worker's body dimension which could be reduced by accurate tools to correct data for body dimension and digital real drawings for facilities. The results showed possibility of application of digital human modeling and ergonomic analysis on informal work operations as well as formal operations in the shipbuilding industry.

• IE interfaces
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• v.16 no.2
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• pp.258-267
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• 2003

Recently, virtual reality technologies have been rapidly developed and realtime virtual simulation methods have been extensively employed for several application areas such as game, sports, manufacturing, military, and so on. A 3D database in realtime virtual simulation plays a key role because it makes users feel reality in virtual space. In a application view of 3D database, a systematic construction approach is required to reduce its construction time and increase its quality. However, many researches have been mostly focused on realtime graphic issues and its key technologies. In virtual simulation of transportation equipments, this paper proposes a systematic construction process of 3D database consisting of four stages as follows: 1) determine the activity space of a equipment, 2) collect data related to 3D database construction, 3) make a 3-dimensional modeling strategy, and 4) generate and evaluate a 3D model. This paper also introduces a new procedure of 3D environment modeling, which summarizes and expands our modeling experiences, to be used as a modeling guide.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.1
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• pp.173-183
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• 2011

Global logistics including Korea had developed at various fields through the developed IT technology. In addition, in changing into Internet based digital economy times, economic and logistics activities became extending into worldwide over the cross-border. Logistics activity performed by off-line rapidly changed in real environment. But, unfortunately business process modeling about the whole logistics was not happened, even though process modeling had done by transport stages or logistics entities. Therefore, it is difficult to grasp the whole logistics. Additional cost and time was requested due to no association between logistics entities and invisibility. So, this paper has to be process modeling for logistics industry domain. For objective modeling, work area shall be divided and it extracts general work process per each area. And then it defines subprocess of general work process. Cargo tracking in logistics industry domain means to grasp the status and present states at transportation or storage stage. This paper defines business process and data model for electronic processed work area using the UN/CEFACT standard modeling methodology.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.160-167
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• 1998

Recent world-wide interest in activity-based travel behavior modeling has generated an entirely new perspective on how the profession views the travel demand process. This paper seeks to further promote the case of activity-based travel behavior models by providing some empirical evidence of relationship between travel time and activity duration decision for worker with transportation panel data. The travel time from home to work and from work to home, without activity involvement, is estimated by the Ordinary Least Squares (OLS) method. And, the travel time to and from the selected activity and the activity duration are modeled simultaneously by the Three Stage Least Squares (3SLS) method due to the endogenous relationship between travel time and activity duration. Two kinds of models, OLS and 3SLS, include selectivity bias corrections in a discrete/continuous framework, because of the inter-relationship between the choice of activity type/travel mode (discrete) and the travel time/activity duration (continuous). Estimation is undertaken using a sample of over 1300 household two-day trip diaries collected from the same travelers in the Seattle area in 1989. The behavioral consequences of these models provide interesting and provocative findings that should be of value to transportation policy formulation and analysis.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.221-228
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• 2009

Electronic Product Code Information Services(EPCIS) is an EPCglobal standard for sharing EPC related information between trading partners. EPCIS provides a new important capability to improve efficiency, security, and visibility in the global supply chain. EPCIS data are classified into two categories, master data (static data) and event data (dynamic data). Master data are static and constant for objects, for example, the name and code of product and the manufacturer, etc. Event data refer to things that happen dynamically with the passing of time, for example, the date of manufacture, the period and the route of circulation, the date of storage in warehouse, etc. There are four kinds of event data which are Object Event data, Aggregation Event data, Quantity Event data, and Transaction Event data. This thesis we propose an event-based data model for EPC Information Service repository in RFID based integrated logistics center. This data model can reduce the data volume and handle well all kinds of entity relationships. From the point of aspect of data quantity, we propose a formula model that can explain how many EPCIS events data are created per one business activity. Using this formula model, we can estimate the size of EPCIS events data of RFID based integrated logistics center for a one day under the assumed scenario.