• Journal of the Korean Society of Earth Science Education
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• v.12 no.1
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• pp.18-26
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• 2019

Vietnam is one of the countries most affected by climate change. Therefore, communication activities on climate change in Vietnam are focused with various media such as television, newspapers, radio, internet etc. In particular, Facebook social network is a potential media but less interested and developed. In this topic, Audience Insight tool of the Facebook social network and the online sociological survey method were conducted to assess the current status and effectiveness of climate change communication activities via Facebook in Vietnam today. Vietnam ranks seventh in the world with 58 million users. However, the number of climate change communication fanpages has only about 15 fanpages with the largest number of followings is 94,721 persons. Among of the 10 most contented Facebook users in Vietnam today, there is no fanpage related to climate change. The results of research and evaluation two fanpages of climate change communication that are the most and most frequent followers in Vietnam showed that climate change communication via Facebook in Vietnam is not as effective as expected. At the same time, online survey results also pointed out the causes of the above problems. This is the scientific basis for management agencies to find the solutions to promote the strength of Facebook social network in climate change communication in the future.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.406-412
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• 2019

In this paper, we propose two algorithms for classifying services with similar delay characteristics into three classes and allocating radio resources according to priority in LTE-A system where H2H and M2M services coexist. The first is to allocate resources from the higher priority class to the lower priority class, and each class gives priority to H2H over M2M, and the other is to give priority to H2H regardless of delay characteristics except for the class with the highest priority. The RA success probability was analyzed according to the access rate(${\alpha}$) of M2M devices in each class. In comparison with the conventional systems, it was improved from 0.5 to 0.52 for ${\alpha}_{2M}=0.05$ in two classes. In the three classes, the success probability was slightly increased from 0.5 to 0.57 for ${\alpha}_{2M}={\alpha}_{3M}=1$ and from 0.5 to 0.58 for ${\alpha}_{2M}=0.5$ and ${\alpha}_{3M}=0.1$. Although 6 services are considered in the proposed scheme, the RA success probability is almost similar to the previous scheme because the average arrival rate of H2H of each class is set to the same.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1261-1270
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• 2022

The purpose of this study is to collect and analyze information related to water leaks that cannot be easily accessed, and utilized by using the news search results that people can easily access. We applied a web crawling technique for extracting big data news on water leakage accidents in the water supply system and presented an algorithm in a procedural way to obtain accurate leak accident news. In addition, a data analysis technique suitable for water leakage accident information analysis was developed so that additional information such as the date and time of occurrence, cause of occurrence, location of occurrence, damaged facilities, damage effect. The primary goal of value extraction through big data-based leak analysis proposed in this study is to extract a meaningful value through comparison with the existing waterworks statistical results. In addition, the proposed method can be used to effectively respond to consumers or determine the service level of water supply networks. In other words, the presentation of such analysis results suggests the need to inform the public of information such as accidents a little more, and can be used in conjunction to prepare a radio wave and response system that can quickly respond in case of an accident.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.223-243
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• 1989

The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.1-9
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• 2016

Train control systems have changed from wayside electricity-centric to onboard communications-centric. The latest train control system, the CBTC system, has high efficiency for interval control based on two-way radio communications between the onboard and wayside systems. However, since the wayside system is the center of control, the number of input trains to allow a wayside system is limited, and due to the cyclic-path control flows between onboard and wayside systems, headway improvement is limited. In this paper, we propose a train interval-control and train-centric distributed interlocking algorithm for an autonomous train-driving control system. Because an autonomous train-driving control system performs interval and branch control onboard, both tracks and switches are shared resources as well as semaphore elements. The proposed autonomous train-driving control performs train interval control via direct communication between trains or between trains and track-side apparatus, instead of relying on control commands from ground control systems. The proposed interlocking algorithm newly defines the semaphore scheme using a unique key for the shared resource, and a switch that is not accessed at the same time by the interlocking system within each train. The simulated results show the proposed autonomous train-driving control system improves interval control performance, and safe train control is possible with a simplified interlocking algorithm by comparing the proposed train-centric distributed interlocking algorithm and various types of interlock logic performed in existing interlocking systems.

• Hwankyungkyoyuk
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• v.18 no.2 s.27
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• pp.76-89
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• 2005

The objectives of this study are to identify the environmental consumer behavior, to examine the degree of environmental consumer behavior of the junior high school students, and to investigate the educational system of a school which influence the consumer behavior. The data used in this study are 368 male and female students in 9th grade in Anyang City, Kyunggi-do province. Statistics used for data analysis are means, standard deviation, t-test, and Multiple Regression Analysis. The results of the research are summarized as follows : First of all, as a tendency of the environmental consumer behavior of junior high students, the primary factor to the environmental problems was media, and among those, TV and radio was the medium to environmental problems. This implies the fact that the time juveniles interact with mass media is significantly growing, which means that transmitting environmental problems by programs targeted to adolescences through mass media would be effective. Next, the disposal process showed the highest environmental consumer behavior, followed by the consuming and purchasing process. Education on the purchasing process will be necessary to encourage environmental consumer behavior. The route of obtaining environmental knowledge was basically from school and the level of the average environmental knowledge fumed out to be low. This shows the need to produce and distribute media education materials because educating the conclusion of actual experiments will be more effective than that of theoretical studies. The conformity showed general indifference on environmental consumer behavior and the environmental resources were normally collected seperated. Conformity is a cultural bond teenagers think important, therefore education available for students about the same age should be developed. Next, the value intention of the surveyed showed that the ecological intention was highest, followed by economic and convenience intentions. This means the morale of the junior high students to environmental consumer behavior is set sound. Females tended to act more environmentally, while males showed more intention to economic causes. Also, the students of the boys-only or girls-only schools showed higher environmentally sound behavior in disposal processes. Finally, the environmental consumer behavior was influenced most by environmental consumer behavior of the conformity group, followed by ecological morale, frequency of encountering environmental problems, gender, environmental knowledge, whether the school was boys-only or girls-only or not, economical morale, respectively. The largest factor affecting the consumer activity of the purchase, consumption, and disposal process was environmental consumer behavior of the conformity group, along with the ecological morale, and the frequency of encountering environmental problems. This implies that conformity group is a large factor to the juveniles and a plan to entice the environmental consumer behavior of conformity groups are necessary.

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.339-346
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• 2020

Background: Cnidium officinale Makino have been used in traditional medicine in Northeast Asia. Although gamma-ray mutagenesis has been used to develop breeding resources with novel characteristics, research on the radiation sensitivity of C. officinale Makino is limited. Hence, the optimal gamma-ray dosage for mutation breeding in C. officinale Makino was investigated. Methods and Results: Seedstocks were exposed to doses of gamma rays (5 Gy - 50 Gy), and subsequently planted in a greenhouse. After 30 days of sowing, the survival rates and growth decreased rapidly at doses above 20 Gy, while all individuals died at 50 Gy. The median lethal dose (LD₅₀) was 25.65 Gy, and the median reduction doses (RD₅₀) for plant height, number of stems, and fresh weight were 12.81, 9.32, and 23.26 Gy, respectively. Post-irradiation levels of malondialdehyde (MDA), peroxidase (POD), and chlorophyll in the aerial parts of the plant were quantified using spectrophotometry. Relative to the controls, the levels of MDA and POD increased, while the level of chlorophyll decreased at doses ≥ 10 Gy, indicating cellular damage. Conclusions: A dose of 20 Gy was found to be optimal for mutation breeding in C. officinale Makino.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.40-46
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• 2010

Multi-user MIMO (Multiple-Input Multiple-Output) systems require collaborative PF schedulers to improve the performance of the log sum of average transmission rates. While the performance of single cell based conventional PF schedulers has been evaluated over various channel conditions, scheduling algorithms by multiple base stations which select multiple users over a given time frame and their performance require further investigations. In this paper, we apply a collaborative PF scheduler to the distributed multi-user MIMO system, which assigns radio resources to multiple users by exchanging user channel information from base stations located in three adjacent sectors. We further evaluate its performance in terms of the log sum of average transmission rates. The performance is compared to that of the full-search collaborative PF scheduler which searches over all possible combinations of user groups, and that of a parallel PF scheduler that determines users without channel information exchange among base stations. We show the log sum of average transmission rates of the collaborative PF scheduler outperforms that of the parallel PF scheduler in low percentile region. In addition, the collaborative PF scheduler exhibits a negligible performance degradation when compared to the full-search collaborative PF scheduler while a significant reduction of the computational complexity is achievable at the same time.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.2
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• pp.85-93
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• 2004

In recent years, technology has advanced so much, especially in the developed world, such that its application in development activities may be lagging behind. The lag between technological advances and its application affects agrometeorological science as well. This paper discusses technological advances that may be better used to communicate agrometeorological information. It is important to bear in mind that technological advances are only channels of communication that may be used to speed up the transference of information from the source to the user. The paper begins with a review of the definitions of 'communication' to put the discussion into context. After reviewing several papers, in simple terms, communication can be defined as the sharing of meaning. The paper also looks at operational communications channels and comes to a conclusion that operational communications channels are pretty much universal irrespective of the development level of a country, although some are more easily accessible in some parts of the world than others. The common communications channels include: newspapers, farming papers, radio, television, fax, email, mobile phones (SMS) and Internet web sites. As part of technological advances, mobile phones are becoming increasingly useful all over the world. In order to make better use of this technology, it is important far those that will use this technology to understand how the technology works, not necessarily in detail, but to be able to operate the technology and obtain the data they need. When it comes to constraints, communication of agrometeorological information requires a substantial amount of resources and it is generally expensive especially when sophisticated models must be operated.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.137-143
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• 2015

A delay-line type time-to-digital converter (TDC) implemented in a field-programmable gate array (FPGA) is most widely owing due to its simple structure and high conversion rate. However, the delay-line type TDC suffers from nonlinearity error caused by the long delay-line because its time interval measurement range is determined by the length of the used delay line. In this study, a new TDC structure with a shorter delay line by taking a pulse train as an input is proposed for improved time accuracy and efficient use of resources. The proposed TDC utilizes a pulse-train with four transitions and a transition state detector that identifies the used transition among four transitions and prevents the meta-stable state without a synchronizer. With 72 delay cells, the measured resolution and maximum non-linearity were 20.53 ps, and 1.46 LSB, respectively, and the time interval measurement range was 5070 ps which was enhanced by approximately 343 % compared to the conventional delay-line type TDC.