• Environmental and Resource Economics Review
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• v.33 no.3
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• pp.203-239
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• 2024

The introduction of a regional differential electricity rate system is being discussed, and the LMP (Locational Marginal Price) method is mentioned as a promising alternative. Under this background, this study analyzed a mathematical model and suggests that the LMP method produces results that maximize social welfare. The analysis was conducted separately for long-term decision-making where transmission capacity can be expanded, and for short-term decision-making in which transmission capacity is given. The analysis for short-term decision-making was conducted for peak load situations where capacity is insufficient and for non-load situations with spare capacity. The results of the analysis suggested that the price to maximize social welfare is equal to the marginal power generation cost by region, and the difference in marginal cost by region reflects the value lost due to transmission loss and compensation for transmission network investment. In addition, if the transmission capacity is less than the optimal capacity, the compensation for transmission network investment exceeds the incremental cost, providing an incentive to invest in the transmission network. If the transmission capacity exceeds the optimal capacity, the compensation for transmission network investment becomes lower than incremental cost or zero and the investment is not recovered, suppressing the investment in transmission networks. The results are the same as the LMP method suggests, and this means that this method maximizes social welfare and provides an optimal transmission network investment signal. The above analysis results contribute to understanding the characteristics of LMP. In addition, this study discussed what changes are needed in the electricity market when introducing the LMP concept.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.159-185
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• 2016

Planning a multi-day trip is a complex, yet time-consuming task. It usually starts with selecting a list of points of interest (POIs) worth visiting and then arranging them into an itinerary, taking into consideration various constraints and preferences. When choosing POIs to visit, one might ask friends to suggest them, search for information on the Web, or seek advice from travel agents; however, those options have their limitations. First, the knowledge of friends is limited to the places they have visited. Second, the tourism information on the internet may be vast, but at the same time, might cause one to invest a lot of time reading and filtering the information. Lastly, travel agents might be biased towards providers of certain travel products when suggesting itineraries. In recent years, many researchers have tried to deal with the huge amount of tourism information available on the internet. They explored the wisdom of the crowd through overwhelming images shared by people on social media sites. Furthermore, trip planning problems are usually formulated as 'Tourist Trip Design Problems', and are solved using various search algorithms with heuristics. Various recommendation systems with various techniques have been set up to cope with the overwhelming tourism information available on the internet. Prediction models of recommendation systems are typically built using a large dataset. However, sometimes such a dataset is not always available. For other models, especially those that require input from people, human computation has emerged as a powerful and inexpensive approach. This study proposes CYTRIP (Crowdsource Your TRIP), a multi-day trip itinerary planning system that draws on the collective intelligence of contributors in recommending POIs. In order to enable the crowd to collaboratively recommend POIs to users, CYTRIP provides a shared workspace. In the shared workspace, the crowd can recommend as many POIs to as many requesters as they can, and they can also vote on the POIs recommended by other people when they find them interesting. In CYTRIP, anyone can make a contribution by recommending POIs to requesters based on requesters' specified preferences. CYTRIP takes input on the recommended POIs to build a multi-day trip itinerary taking into account the user's preferences, the various time constraints, and the locations. The input then becomes a multi-day trip planning problem that is formulated in Planning Domain Definition Language 3 (PDDL3). A sequence of actions formulated in a domain file is used to achieve the goals in the planning problem, which are the recommended POIs to be visited. The multi-day trip planning problem is a highly constrained problem. Sometimes, it is not feasible to visit all the recommended POIs with the limited resources available, such as the time the user can spend. In order to cope with an unachievable goal that can result in no solution for the other goals, CYTRIP selects a set of feasible POIs prior to the planning process. The planning problem is created for the selected POIs and fed into the planner. The solution returned by the planner is then parsed into a multi-day trip itinerary and displayed to the user on a map. The proposed system is implemented as a web-based application built using PHP on a CodeIgniter Web Framework. In order to evaluate the proposed system, an online experiment was conducted. From the online experiment, results show that with the help of the contributors, CYTRIP can plan and generate a multi-day trip itinerary that is tailored to the users' preferences and bound by their constraints, such as location or time constraints. The contributors also find that CYTRIP is a useful tool for collecting POIs from the crowd and planning a multi-day trip.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.822-828
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• 1998

Binary system of water and polyoxyethylene dodecyl ether, $C_{12}H_{25}(OCH_2CH_2)nOH$, have been studied by $^1H$ NMR techniques. For n=5($C_{12}EO_5$) and n=8($C_{12}EO_8$), the self-diffusion coefficients of nonionic surfactants in the isotropic phase($L_1$) have been measured by using pulsed field gradient technique for a range of temperature and concentrations. In addition the line widths of the different proton signals have been monitored, and samples of some liquid crystalline characteristic were also studied. Dramatic Broadening of the methylene signals of the alkyl($C_{12}H_{25}$) chain is observed as the hexagonal liquid crystalline phase is approached in the $C_{12}EO_5-$water system, while only small broadening is observed in the $C_{12}EO_8-$water system. It was shown that there was a growth of $C_{12}EO_5$ micelles to rods with increasing concentrations, while the $C_{12}EO_8-$ micelles at low temperature remain small in the concentration range. The self-diffusion coefficients of the surfactants decrease rapidly with increasing concentration until a minimum is reached after which there is slow increase. The location of the minimum point occurs at lower concentrations the temperature is close to the cloud point, where the system separate into two isotropic phase. In the line width studies, broadening is found at a certain temperature interval when the concentration is increased in the $C_{12}EO_5$ system. The results indicate that the surfactant aggregates grow in size at the cloud point is approached. The aggregates seem to be flexible and probably not to be of a definite shape close to the cloud point. In the $C_{12}EO_8$ system, the micelles are much less affected by an increase in temperature and micellar growth can't be unambiguously established. The methylene signals of the ethylene oxide moieties consistantly show narrower $^1H$ signals, showing that in the aggregates they are less ordered than the chain methylenes. The various changes in aggregate size and shape are correlated with the stability ranges of the isotropic and liquid crystalline phases according to phase diagrams from the literature. Both aggregate size and phase structure are in qualitative agreement with concentration based on the effective shape of the molecules at different temperature and concentration.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.107-120
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• 2014

This study proposes a novel recommender system using the structural hole analysis to reflect qualitative and emotional information in recommendation process. Although collaborative filtering (CF) is known as the most popular recommendation algorithm, it has some limitations including scalability and sparsity problems. The scalability problem arises when the volume of users and items become quite large. It means that CF cannot scale up due to large computation time for finding neighbors from the user-item matrix as the number of users and items increases in real-world e-commerce sites. Sparsity is a common problem of most recommender systems due to the fact that users generally evaluate only a small portion of the whole items. In addition, the cold-start problem is the special case of the sparsity problem when users or items newly added to the system with no ratings at all. When the user's preference evaluation data is sparse, two users or items are unlikely to have common ratings, and finally, CF will predict ratings using a very limited number of similar users. Moreover, it may produces biased recommendations because similarity weights may be estimated using only a small portion of rating data. In this study, we suggest a novel limitation of the conventional CF. The limitation is that CF does not consider qualitative and emotional information about users in the recommendation process because it only utilizes user's preference scores of the user-item matrix. To address this novel limitation, this study proposes cluster-indexing CF model with the structural hole analysis for recommendations. In general, the structural hole means a location which connects two separate actors without any redundant connections in the network. The actor who occupies the structural hole can easily access to non-redundant, various and fresh information. Therefore, the actor who occupies the structural hole may be a important person in the focal network and he or she may be the representative person in the focal subgroup in the network. Thus, his or her characteristics may represent the general characteristics of the users in the focal subgroup. In this sense, we can distinguish friends and strangers of the focal user utilizing the structural hole analysis. This study uses the structural hole analysis to select structural holes in subgroups as an initial seeds for a cluster analysis. First, we gather data about users' preference ratings for items and their social network information. For gathering research data, we develop a data collection system. Then, we perform structural hole analysis and find structural holes of social network. Next, we use these structural holes as cluster centroids for the clustering algorithm. Finally, this study makes recommendations using CF within user's cluster, and compare the recommendation performances of comparative models. For implementing experiments of the proposed model, we composite the experimental results from two experiments. The first experiment is the structural hole analysis. For the first one, this study employs a software package for the analysis of social network data - UCINET version 6. The second one is for performing modified clustering, and CF using the result of the cluster analysis. We develop an experimental system using VBA (Visual Basic for Application) of Microsoft Excel 2007 for the second one. This study designs to analyzing clustering based on a novel similarity measure - Pearson correlation between user preference rating vectors for the modified clustering experiment. In addition, this study uses 'all-but-one' approach for the CF experiment. In order to validate the effectiveness of our proposed model, we apply three comparative types of CF models to the same dataset. The experimental results show that the proposed model outperforms the other comparative models. In especial, the proposed model significantly performs better than two comparative modes with the cluster analysis from the statistical significance test. However, the difference between the proposed model and the naive model does not have statistical significance.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.42-46
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• 2016

Purpose Mammography is the most widely used scan for the early diagnosis since it is possible to observe the anatomy of the breast. however, The sensitivity is markedly reduced in high-risk patients with dense breast. Molecular Breast Imaging (MBI) sacn is possible to get the high resolution functional imaging, and This new neclear medicine technique get the more improved diagnostic information through It is useful for confirmation of tumor's location in dense breast. The purpose of this study is to evaluate the usefulness of MBI for tumor diagnosis in patients with dense breast. Materials and Methods We investigated 10 patients female breast cancer with dense breast type who had visited the hospital from September 1st to Octorber 10th, 2015. The patients underwent both MBI and Mammography. MBI (Discovery 750B; General Electric Healthcare, USA) scan was 99mTc-MIBI injected with 20 mCi on the opposite side of the arm with the lesions, after 20 minutes, gained bilateral breast CC (CranioCaudal), MLO (Medio Lateral Oblique) View. Mammography was also conducted in the same posture. MBI and Mammography images were compared to evaluate the sensitivity and specificity of each case utilizing both image and two images in blind tests. Results The results of the blind test for breast cancer showed that the sensitivity of Mammography, MBI scan was 63%, 89%, respectively, and that their specificity was 38%, 87%, respectively. Using both the Mammography and MBI scan was Sensitivity 92%, specificity 90%. Conclusion This research has found that, The tumor of dense tissue that can not easily distinguishable in Mammography is possible to more accurate diagnosis since It is easy to visually evaluation. But MBI sacn has difficulty imaging microcalcificatons, If used in conjunction with mammography it is thought to give provide more diagnostic information.

• Journal of radiological science and technology
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• v.34 no.4
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• pp.341-349
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• 2011

This study was to measure the patient dose difference between 3D treatment planning CT and 4D respiratory gating CT. Study was performed with each 10 patients who have lung and liver cancer for measured patient exposure dose by using SOMATON SENSATION OPEN(SIMENS, GERMANY). CTDIvol and DLP value was used to analyze patient dose, and actual dose was measured in the location of liver and kidney for abdominal examination and lung, heart and spinal cord for chest examination. Rando phantom were used for the experiment. OSLD was used for in-vitro and in-vivo dosimetry. Increasing overall actual dose in 4D respiratory gated CT-simulation using OSLD increase the dose by 5.5 times for liver cancer patients and 6 times for lung cancer patients. In CT simulation of 10 lung cancer patients, CTDIvol value was increased by 5.7 times and DLP 2.4 times. For liver cancer patients, CTDIvol was risen by 3.8 times and DLP 1.6 times. The accuracy of treatment volume could be increased in 4D CT planning for position change due to the breaths of patient in the radiation therapy. However, patients dose was increased in 4D CT than 3D CT. In conclusion, constant efforts is required to reduce patients dose by reducing scan time and scan range.

• Journal of Internet Computing and Services
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• v.22 no.1
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• pp.41-50
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• 2021

Cyber Kill Chain is derived from Kill chain of traditional military terms. Kill chain means "a continuous and cyclical process from detection to destruction of military targets requiring destruction, or dividing it into several distinct actions." The kill chain has evolved the existing operational procedures to effectively deal with time-limited emergency targets that require immediate response due to changes in location and increased risk, such as nuclear weapons and missiles. It began with the military concept of incapacitating the attacker's intended purpose by preventing it from functioning at any one stage of the process of reaching it. Thus the basic concept of the cyber kill chain is that the attack performed by a cyber attacker consists of each stage, and the cyber attacker can achieve the attack goal only when each stage is successfully performed, and from a defense point of view, each stage is detailed. It is believed that if a response procedure is prepared and responded, the chain of attacks is broken, and the attack of the attacker can be neutralized or delayed. Also, from the point of view of an attack, if a specific response procedure is prepared at each stage, the chain of attacks can be successful and the target of the attack can be neutralized. The cyber command and control system is a system that is applied to both defense and attack, and should present defensive countermeasures and offensive countermeasures to neutralize the enemy's kill chain during defense, and each step-by-step procedure to neutralize the enemy when attacking. Therefore, thist paper proposed a cyber kill chain model from the perspective of defense and attack of the cyber command and control system, and also researched and presented the threat classification/analysis/prediction framework of the cyber command and control system from the defense aspect

• Korea Science and Art Forum
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• v.37 no.1
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• pp.87-97
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• 2019

The study began in recent years with the aim of grasping the nation's medical status following the fast-growing trend of international medical tourism and attracting foreign patients, among other things, Busan, which ranks second in attracting foreign patients after the nation's capital, Seoul, has been highly active in the past eight years, with foreign patients rising by about 426 percent, and Russian patients entering the sea. In addition, Gimhae and Changwon, the Busan-based Gyeongsangnam-do region, ranked first and second in number of foreign residents, and are inhabited by a variety of foreign workers. Medical institutions, such as hospitals, should be able to find directions within hospitals. It is also a space where information in various languages, including Korean, English, Chinese, or Russian, must be delivered in a single medium. Based on this research, the purpose of this research is to provide converged information that helps foreigners who are not familiar with Korean language easily understand the proposed recognition system when visiting hospitals. Therefore, this paper is applied to a multi-language survey of six medical institutions (A, B, C, D, E, F) at the university hospital in Busan, and 10 medical institutions (R, J) in Gimhae, South Gyeongsang Province with high foreign residents. Research results and contents are as follows. First, the results of analyzing the design of the sinusoidal system show that the font uses colorless Gothic fonts, arrows, and pictograms to introduce the design of a typical hospital sign system. Second, the results of the multi-lingual situation were found to have only two languages in the system, such as Korean and English, and to have four languages, including Korean, English, Chinese, and Russian, according to their geographical location. However, it was judged that most medical institutions currently have only two languages (Korean, English) that may cause some discomfort in terms of language for foreign patients in non-English speaking countries. Based on these findings, it is necessary to propose designs that are considered by Koreans as well as foreign users in the use of multilingual hospital sign systems.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.198-215
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• 2020

Official development assistance refers to assistance provided by governments and other public institutions in donor countries, aimed at promoting economic development and social welfare in developing countries. The purpose of this research is to examine the construction process of the "Myanmar Cultural Heritage Management System" that is underway as part of the ODA project to strengthen cultural and artistic capabilities and analyze the achievements and challenges of the Digital Cultural Heritage ODA. The digital cultural heritage management system is intended to achieve the permanent preservation and sustainable utilization of tangible and intangible cultural heritage materials. Cultural heritage can be stored in digital archives, newly approached using computer analysis technology, and information can be used in multiple dimensions. First, the Digital Cultural Heritage ODA was able to permanently preserve cultural heritage content that urgently needed digitalization by overcoming and documenting the "risk" associated with cultural heritage under threat of being extinguished, damaged, degraded, or distorted in Myanmar. Second, information on Myanmar's cultural heritage can be systematically managed and used in many ways through linkages between materials. Third, cultural maps can be implemented that are based on accurate geographical location information as to where cultural heritage is located or inherited. Various items of cultural heritage were collectively and intensively visualized to maximize utility and convenience for academic, policy, and practical purposes. Fourth, we were able to overcome the one-sided limitations of cultural ODA in relations between donor and recipient countries. Fifth, the capacity building program run by officials in charge of the beneficiary country, which could be the most important form of sustainable development in the cultural ODA, was operated together. Sixth, there is an implication that it is an ODA that can be relatively smooth and non-face-to-face in nature, without requiring the movement of manpower between countries during the current global pandemic. However, the following tasks remain to be solved through active discussion and deliberation in the future. First, the content of the data uploaded to the system should be verified. Second, to preserve digital cultural heritage, it must be protected from various threats. For example, it is necessary to train local experts to prepare for errors caused by computer viruses, stored data, or operating systems. Third, due to the nature of the rapidly changing environment of computer technology, measures should also be discussed to address the problems that tend to follow when new versions and programs are developed after the end of the ODA project, or when developers have not continued to manage their programs. Fourth, since the classification system criteria and decisions regarding whether the data will be disclosed or not are set according to Myanmar's political judgment, it is necessary to let the beneficiary country understand the ultimate purpose of the cultural ODA project.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.127-135
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• 2021

To respond to the threat of global warming, countries around the world are promoting the spread of renewable energy and reduction of carbon emissions. In accordance with the United Nation's Sustainable Development Goal to combat climate change and its impacts, global automakers are pushing for a full transition to electric vehicles within the next 10 years. Electric vehicles can be a useful means for reducing carbon emissions, but in order to reduce carbon generated in the stage of producing electricity for charging, a power generation system using eco-friendly renewable energy is required. In this study, we propose a smart electric mobility operating system integrated with off-grid solar power plants established in Tanzania, Africa. By applying smart monitoring and communication functions based on Arduino-based computing devices, information such as remaining battery capacity, battery status, location, speed, altitude, and road conditions of an electric vehicle or electric motorcycle is monitored. In addition, we present a scenario that communicates with the surrounding independent solar power plant infrastructure to predict the drivable distance and optimize the charging schedule and route to the destination. The feasibility of the proposed system was verified through test runs of electric motorcycles. In considering local environmental characteristics in Tanzania for the operation of the electric mobility system, factors such as eco-friendliness, economic feasibility, ease of operation, and compatibility should be weighed. The smart electric mobility operating system proposed in this study can be an important basis for implementing the SDGs' climate change response.