• Korean System Dynamics Review
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• v.1 no.2
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• pp.5-31
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• 2000

The summit meeting of the South North Korean leaders was a turning point in the relationships between the two countries. It was followed by the Red-Cross Meeting, Minister-Level Meeting, economic agreements, which have increased the relationship more colorful in both quantities and qualities. However, the half-century period for separation was too long to overcome all the problems by only one event. The two countries have quite different social systems; one politically strong person is governing the North, while many interest groups are involved in political decision making processes in the South. In short, it would take a long time to settle down all the problems residing between the two countries. A system dynamics model is developed to describe the long term dynamics of the relations between the South and North Koreas. As a first attempt, the model focuses only on the diplomatic meeting issues between the South and North. The model aggregates diplomatic issues into 5 categories; economic issues, security issues, infrastructure, cultural issues, and past problems. It assumes that there would not be any dramatic changes between the two countries. It is a conceptual model composed of around 200 variables, and should not be used as a forecast tool. However, it captures most of the logics discussed in the papers and conferences concerning the South and North Korea relations. Many sensitivity studies and Monte Carlo simulations have shown that the simulation results matches with mental models of experts; that is the model can be used as a learning tool or as a secondary opinion until the data required by the model is collected. In order to analyze the current situation, five scenarios are simulated and analyzed; the functional approach, the conditional approach, the balanced approach, the circumstantial approach, and the strategic approach. The functional approach represents that the South makes efforts in the area where the possibility of agreement is high for the next 10 years. The conditional approach is a scenario where the South impose all difficult issues as conditions for resolving other diplomatic issues. The balanced approach is resolving the five issues with the same priorities, while the circumstantial approach is resolving issues which seem to be resolved easily. Finally, another optimum approach has been seek using the system dynamics model developed. The optimum strategy (it is named as the strategic approach) was strikingly different from other four approaches. The optimum strategy is so complicated that no one could find it with mental model(or by just insights). Considering that the system dynamic model used to find the optimum is a simplifind (maybe over simplified) version of the reality, it is concluded that a well designed system dynamics model would be of great help to resolving the complicated diplomatic problems in any kind.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.103-138
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• 2009

In this article we examine a unique data set of intraday fair disclosure(FD) releases to shed light on market efficiency within the trading day. Specifically, this paper analyze the response of stock prices on fair disclosure disseminated in real-time through KIND(Korea Investor's Network for Disclosure) on Korea stock exchange during the period from January 2003 to September 2004. We find that the prices of stock experiences a statistically and economically significant increase beginning seconds after the fair disclosure is initially announced and lasting approximately two minutes. The stock price responds more strongly to fair disclosure on smaller firm but the response to fair disclosure on the largest firm stock is more gradual, lasting five minutes. We also examine the profitability of a short-term trading strategy based on dissemination of fair disclosure. After controlling for trading costs we find that trader who execute a trade following initial disclosure generate negative profits, but trader buying stock before initial disclosure realize statistically significant positive profit after two minute of disclosure. Summarizing overall results, our evidence supports that security prices on Korea stock exchange reflects all available information within two minutes and the Korea stock market is semi-strongly efficient enough that a trader cannot generate profits based on widely disseminated news unless he acts almost immediately.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.233-238
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• 2020

In the cloud environment, IoT devices using sensors and wearable devices are being applied in various environments, and technologies that accurately determine the information generated by IoT devices are being actively studied. However, due to limitations in the IoT environment such as power and security, information generated by IoT devices is very weak, so financial damage and human casualties are increasing. To accurately collect and analyze IoT information, this paper proposes a topographic information-based key management technique that considers IoT information errors. The proposed technique allows IoT layout errors and groups topographic information into groups of dogs in order to secure connectivity of IoT devices in the event of arbitrary deployment of IoT devices in the cloud environment. In particular, each grouped terrain information is assigned random selected keys from the entire key pool, and the key of the terrain information contained in the IoT information and the probability-high key values are secured with the connectivity of the IoT device. In particular, the proposed technique can reduce information errors about IoT devices because the key of IoT terrain information is extracted by seed using probabilistic deep learning.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.211-217
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• 2008

Recently, there are many efforts to support seamless mobility in 802.11 WLANs using IP Layer mobility protocols. The IP layer mobility protocols are the most efficient mechanism to guarantee the service session continuity when IP subnet is changed during handover. Even if the IP layer mobility protocols are quite efficient, the feature of the protocols that had been designed to consider only L3 layer makes it difficult to improve the performance of hand over more and more. Nowadays, to overcome this limitation of IP mobility protocols, many researchers have worked on the mobility protocols integration of different layers (e.g., L2 layer). In this paper, we propose the enhanced Proxy MIPv4 to minimize the latency of handover using MIH protocol in 802.11 WLANs. The proposed mechanism minimizes the latency of authentication by exchanging security keys between Access Routers during handover. Moreover, it also minimizes packet losses by Inter-AP Tunneling and data forwarding.

• Journal of the Korean GEO-environmental Society
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• v.16 no.7
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• pp.43-53
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• 2015

More than 70 percent of the Korean territory consists of mountain area so development of mountain district is essential to urbanize continuously. Thus, technological developments for risk factors and standards and manuals must be needed to prevent mountain disaster. Risk Management Manual should be made and operated in government legislation related to national disaster, but there is still no Emergency Management Standard Manual and Emergency Response-Practical Manual to prevent mountain disaster. This study suggests the improvement plans that are legislated but not established cleary in the field of disaster in urban area. The main items are like as 1) adaptable standard and practical manual to prevent mountain disaster in urban area, 2) reinforcement between managing department and interagency vertically and horizontally in central and local government organization, 3) Personal SOP (Standard Operating Procedure) not EOP (Emergency Operation Plan), 4) considering 13 items selected by Ministry of Public Safety and Security, 5) schematization with personal action plan, 6) check list to do in the event of mountain disaster, and 7) regular practice per quarter.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.719-725
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• 2018

After 9/11 attacks in the U.S, Terrorism has increased the number of unspecified casualties through multi-use facility terror attacks compared to the past. The subsequent London bombings and the self-destruction of Pakistan increased people's fear and social anxiety. As international events have been held in Korea recently, awareness and concern over radioactive terrorism and security management of radioactive materials are increasing. In this paper, we compared the results of different meteorological conditions using HotSpot Code. After creating a possible terror scenario in Korea, sources likely to be use in RDD and Dirty bomb were investigated. The meteorological condition was selected by comparing the Pasquill-Gifford stability class with the most stable condition F and the most unstable condition A. The result value of the A and F condition through simulation were shown not to cause citizens to die from acute effects due to radiological effects. The range of radioactivity is different according to the wind speed and the meteorological stability, and the degree of radioactivity dilution is different according to meteorological conditions. Analysis results are expected to be used for initial response in the event of a radioactive terrorist attack.

• 재활복지
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• v.21 no.3
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• pp.129-146
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• 2017

In an event of an emergency, such as fire in a building, visually impaired and blind people are prone to exposed to a level of danger that is greater than that of normal people, for they cannot be aware of it quickly. Current fire detection methods such as smoke detector is very slow and unreliable because it usually uses chemical sensor based technology to detect fire particles. But by using vision sensor instead, fire can be proven to be detected much faster as we show in our experiments. Previous studies have applied various image processing and machine learning techniques to detect fire, but they usually don't work very well because these techniques require hand-crafted features that do not generalize well to various scenarios. But with the help of recent advancement in the field of deep learning, this research can be conducted to help solve this problem by using deep learning-based object detector that can detect fire using images from security camera. Deep learning based approach can learn features automatically so they can usually generalize well to various scenes. In order to ensure maximum capacity, we applied the latest technologies in the field of computer vision such as YOLO detector in order to solve this task. Considering the trade-off between recall vs. complexity, we introduced two convolutional neural networks with slightly different model's complexity to detect fire at different recall rate. Both models can detect fire at 99% average precision, but one model has 76% recall at 30 FPS while another has 61% recall at 50 FPS. We also compare our model memory consumption with each other and show our models robustness by testing on various real-world scenarios.

• Journal of Industrial Convergence
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• v.21 no.4
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• pp.165-170
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• 2023

There are cases where the mobility impaired have difficulty moving from the moment they leave the house. If guardians also do not have time to entrust their families, who are socially disadvantaged, to a shelter, the guardian has no choice but to check directly in order to know the location of the guardian. The AI home care solution was designed to relieve the anxiety and labor of caregivers and to provide convenience for protection facility officials and users. If more facilities distribute and use services free of charge to non-profit foundations and protective facilities, the concern of guardians will be reduced, and the burden of facility officials who have to manage facility users will be reduced. In this paper, we provide emergency notification services to guardians in the event of an emergency as well as location and status alarms for guardians, which are all data related to movement, in consideration of the mobility vulnerable. Furthermore, it is necessary to provide a service function that recommends the optimal route using a navigation function to ease the convenience and burden of facility officials. It is necessary to alleviate anxiety by providing necessary information to the guardian, such as the location of the shuttle used by the mobile weak and the time of getting on and off. In addition, while providing services for free, the goal is to improve the quality of service for facility managers and the quality of service for the mobility weak.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.667-674
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• 2023

In the event of a disaster occurring within a building, the prompt and efficient evacuation and rescue of occupants within the building becomes the foremost priority to minimize casualties. For the purpose of such rescue operations, it is essential to ascertain the distribution of individuals within the building. Nevertheless, there is a primary dependence on accounts provided by pertinent individuals like building proprietors or security staff, alongside fundamental data encompassing floor dimensions and maximum capacity. Consequently, accurate determination of the number of occupants within the building holds paramount significance in reducing uncertainties at the site and facilitating effective rescue activities during the golden hour. This research introduces a methodology employing computer vision algorithms to count the number of occupants within distinct building locations based on images captured by installed multiple CCTV cameras. The counting methodology consists of three stages: (1) establishing virtual Lines of Interest (LOI) for each camera to construct a multi-camera network environment, (2) detecting and tracking people within the monitoring area using deep learning, and (3) aggregating counts across the multi-camera network. The proposed methodology was validated through experiments conducted in a five-story building with the average accurary of 89.9% and the average MAE of 0.178 and RMSE of 0.339, and the advantages of using multiple cameras for occupant counting were explained. This paper showed the potential of the proposed methodology for more effective and timely disaster management through common surveillance systems by providing prompt occupancy information.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.193-222
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• 1989

The purpose of this study is to review the rights and duties of cargo owners, the party to the contract of international carriage of goods by air under the Warsaw Convention System and the IATA conditions. It is generally known that air freight is the most-cost mode of transportation. However, should there be considerations of total distribution cost, the use of air freight leads exporters to be advantageous in physical distribution. The Warsaw Convention System defined and limited the rights and duties of cargo owners and air carriers paticipating in the international carriage of goods, but it does not regulate every aspect of air transportation. Therefore, the unregulated parts are governed by national laws and by individual contracts of carriage. The International Air Transport Association(lATA), a worldwide organization of airlines, has formulated model conditions of contract for the carriage of cargo. These models are not uniformly followed but they serve as a basis for many of the individual standard form of contracts prepared by air carriers. The contract of air carriage of goods is a contract of adhesion, 'the consignor recognizing and accepting the conditions laid down by the carrier'. There are consignors and carriers as the parties to the contract of international carriage of goods. In addition to his basic right, implied in Warsaw Convention Article 18 and 19, to require devery of the goods in good condition and at the date agreed upon, the consignor has the right to dispose the goods in the course of the journey up to the moment when the consignee is entitled to require delivery. If it is impossible to carry out the orders of the consignor, the carrier must so inform him forthwith. The right conferred on the consignor ceases at the moment when that of the consignee begins in accordance with Warsaw Convention Article 13. Nevertheless, if the consignee declines to accept the air waybill or the goods, or if he cannot be communicated with, the consignor resumes his right of disposition. Unless it is otherwise agreed, it is the duty of the carrier to give notice to the consignee as soon as the goods arrive. The consignee is entitled, on arrival of the goods at the place of destination, to require the carrier to hand over to him the air waybill and to deliver the goods to him, on payment of the charges due and on complying with the conditions of carriage set out in the air waybill. The air waybill is supposed to be made out by the consignor. If the carrier makes it out, he is deemed, subject to proof to the contrary, to have done so on behalf of the consignor, whether there is one air waybill or several, each must be made out in three original parts. The first is for the carrier, the second is for the consignee, and the the third is handed to the consignor when the shipment has been accepted. The consignor is responsible for the correctness of the particulars and statement concerning the cargo appearing in the air waybill. Each of the original parts of the air waybill has evidential value and possession of his part is a condition for the exercise by the consignor or consignee of his rights under the contract of carriage. Hague Protocol set forth in Article 9 that nothing in this. Convention prevents the issue of a negotiable air waybill, but Montreal Additional Protocol No. 4 deleted this article. All charges applicable to a shipment are payable in cash at the time of acceptance thereof by the carrier in case of a prepaid shipment or at the time of delivery thereof by the carrier in case of a collect shipment. The carrier shall have lien the cargo for unpaid charges and, in the event of non-payment thereof, shall have the right to dispose of the cargo at public or private sale and pay itself out of the proceeds of such sale any and all such amounts. In conclusion, the Warsaw Convention System has the character of ambiguity in various respects, not only in the part of the forms of documents but also in conditions of contract. Accordingly, the following propositions might be considered: (1) If the carrier does not obey the orders of the consignor for the disposition of the goods without proper reasons, he will be liable strictly for any damage which may be caused thereby to the cargo owner. The special agreement and carrier's conditions of carriage which limit unreasonably the consignor's right of disposition of the goods will be nullified. (2) The instrument of the Warsaw Convention System which is not yet in force(Montreal Additional Protocol No. 4) would considerably simplfy the processing and keeping of computerized records of the carriage. Until this instrument enters into force, the airlines will be faced with practical problems preventing them to substitute computerized data processing techniques for the formal issuance of the documents. Accordingly, Montreal Additional Protocol No. 4 should become effective as soon as posisble. From a practical point of view in the international trade, the issuance of negotiable air waybill should be permitted for the security of the bank.