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The Effectiveness of CT and MRI Contrast Agent for SUV in 18F-FDG PET/CT Scanning (18F-FDG PET/CT 검사에서 정량분석에 관한 CT와 MRI 조영제의 효과)

  • Cha, Sangyoung;Cho, Yonggwi;Lee, Yongki;Song, Jongnam;Choi, Namgil
    • Journal of the Korean Society of Radiology
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    • v.10 no.4
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    • pp.255-261
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    • 2016
  • In this study, among various factors having influence on SUV, we intended to compare and analyze the change of SUV using CT(4 type) and MRI(3 type) contrast agents which are commercialized now. We used Discovery 690 PET/CT(GE) and NEMA NU2 - 1994 PET phantom as experimental equipment. We have conducted a study as follows; first, we filled distilled water to phantom about two-thirds and injected radioisotope(18F-FDG 37 MBq), contrast agent. Second, we mixed CT contrast agent with distilled water and MRI contrast agent with that water separately. And then, we stirred the fluid and filled distilled water fully not to make air bubble. In emission scan, we had 15minutes scanning time after 40 minutes mixing contrast agent with distilled water. In transmission scan, we used CT scanning and its measurement conditions were tube voltage 120 kVp, tube current 40 mA, rotation time 0.5 sec, slice thickness 3.27 mm, DFOV 30 cm. Analyzing results, we set up some ROIs in 10th, 15th, 20th, 25th, 30th slice and measured SUVmean, SUVmax. Consequently, all images mixed 3 types of MRI contrast agent with distilled water have high SUVmean as compared with pure FDG image but there was no statistical significance. In SUVmax, they have high score and there was statistical significance. And other 4 images mixed 4 types of CT contrast agent with distilled water have significance in both SUVmean and SUVmax. Attenuation correction in PET/CT has been executed through various methods to make high quality image. But we figured out that using CT and MRI contrast agents before PET/CT scanning could make distortion of image and decrease diagnostic value. In that reason, we have to sort out the priority of examination in hospital not to disturb other examination's results. Through this process, we will be able to give superior medical service to our customers.

Landslide Vulnerability Mapping considering GCI(Geospatial Correlative Integration) and Rainfall Probability In Inje (GCI(Geospatial Correlative Integration) 및 확률강우량을 고려한 인제지역 산사태 취약성도 작성)

  • Lee, Moung-Jin;Lee, Sa-Ro;Jeon, Seong-Woo;Kim, Geun-Han
    • Journal of Environmental Policy
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    • v.12 no.3
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    • pp.21-47
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    • 2013
  • The aim is to analysis landslide vulnerability in Inje, Korea, using GCI(Geospatial Correlative Integration) and probability rainfalls based on geographic information system (GIS). In order to achieve this goal, identified indicators influencing landslides based on literature review. We include indicators of exposure to climate(rainfall probability), sensitivity(slope, aspect, curvature, geology, topography, soil drainage, soil material, soil thickness and soil texture) and adaptive capacity(timber diameter, timber type, timber density and timber age). All data were collected, processed, and compiled in a spatial database using GIS. Karisan-ri that had experienced 470 landslides by Typhoon Ewinia in 2006 was selected for analysis and verification. The 50% of landslide data were randomly selected to use as training data, while the other 50% being used for verification. The probability of landslides for target years (1 year, 3 years, 10 years, 50 years, and 100 years) was calculated assuming that landslides are triggered by 3-day cumulative rainfalls of 449 mm. Results show that number of slope has comparatively strong influence on landslide damage. And inclination of $25{\sim}30^{\circ}C$, the highest correlation landslide. Improved previous landslide vulnerability methodology by adopting GCI. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing landslide mitigation policies.

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Risk Management and Strategies in Airport Security Check (공항 보안검색에 있어서의 위험관리와 대응과제)

  • Kim, Jae-Woon
    • Korean Security Journal
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    • no.34
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    • pp.89-113
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    • 2013
  • Travel by airplane using airport in globalized modern society is familiar to our life but such airport can be a target of terrorists who would threaten our safety. However, aviation terrorism which is represented by 9.11 terror gives horror beyond our imagination to modern people. Since the first airplane hijacking in Peru in 1931 happened, security organization in each nation has taken various prevention measures to block aviation terrorism. The most realistic measures to prevent aviation terrorism would be security check activity to control approach of terrorist that passengers on airplane and cargos are checked to find out dangerous article like explosive etc. But security check activity in Korea shifted to security check activity focused on private security for efficiency of airport operation differently from security check activity in advanced countries where public interests is strengthened according to risk of terror after 9.11 system. That is, since Incheon airport opened in March 2001, security check system focused on the police was changed. Now Incheon international airport Corporation instructs and supervises security check job and private security personnel are in charge of actual security check activity. But this check system has limitation in blocking terror activity by terrorists which is systematized and intelligent as time passes due to deteriorated job satisfaction of private security personnel and confusing supervising system. Accordingly, it is suggested to introduce risk management skill which is one of management strategy of private corporation for security check activity to prevent terror activity. With this skill, risk factors of aviation terror are identified and analyzed regularly, and each process such as setting of priority, activity to reduce risk, and assessment of security is carried out. And it would be necessary to do efforts, for example, to properly change level of security check according to threat of terror such as to place policeman at airport security in case threat of terror is severe. On the other hand, it is necessary to establish national police organization for good communication of security check activity in field and supervising function, which can encourage systematization and specialization of aviation security job.

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A Study on Development of Management Targets and Evaluation of Target Achievement for Non-point Source Pollution Management in Saemangeum Watershed (새만금 비점오염원 관리지역에서의 목표설정 및 달성도 평가방법론 연구)

  • Kim, Eun-Jung;Park, Bae-Kyung;Kim, Yong-Seok;Rhew, Doug-Hee;Jung, Kwang-Wook
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.8
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    • pp.480-491
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    • 2015
  • In this study, methods using LDC (Load Duration Curve) and watershed model were suggested to develope management targets and evaluate target achievement for non-point source pollution management considering watershed and runoff characteristics and possibility for achievement of target. These methods were applied for Saemangeum watershed which was designated as nonpoint source pollution management area recently. Flow duration interval of 5 to 40% was selected as flow range for management considering runoff characteristics and TP was selected as indicator for management. Management targets were developed based on scenarios for non-point source pollutant reduction of management priority areas using LDC method and HSPF model which was calibrated using 4 years data (2009~2012). In the scenario of LID, road sweeping and 50% reduction in CSOs and untreated sewage at Jeonju A20 and 30% reduction in fertilizer and 50% in livestock NPS at Mankyung C03, Dongjin A14 and KobuA14, management targets for Mangyung bridge, Dongjin bridge, Jeonju stream and Gunpo bridge were developed as TP 0.38, 0.18, 0.64 and 0.16 mg/L respectively. When TP loads at the target stations were assumed to have been reduced by a certain percentage (10%), management targets for those target stations were developed as TP 0.35, 0.17, 0.60 and 0.15 mg/L respectively. The result of this study is expected to be used as reference material for management master plan, implementation plan and implementation assessment for non-point source management area.

Electronic Roll Book using Electronic Bracelet.Child Safe-Guarding Device System (전자 팔찌를 이용한 전자 출석부.어린이 보호 장치 시스템)

  • Moon, Seung-Jin;Kim, Tae-Nam;Kim, Pan-Su
    • Journal of Intelligence and Information Systems
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    • v.17 no.4
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    • pp.143-155
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    • 2011
  • Lately electronic tagging policy for the sexual offenders was introduced in order to reduce and prevent sexual offences. However, most sexual offences against children happening these days are committed by the tagged offenders whose identities have been released. So, for the crime prevention, we need measures with which we could minimize the suffers more promptly and actively. This paper suggests a new system to relieve the sexual abuse related anxiety of the children and solve the problems that electronic bracelet has. Existing bracelets are only worn by serious criminals, and it's only for risk management and positioning, there is no way to protect the children who are the potential victims of sexual abuse and there actually happened some cases. So we suggest also letting the students(children) wear the LBS(Location Based Service) and USN(Ubiquitous Sensor Network) technology based electronic bracelets to monitor and figure out dangerous situations intelligently, so that we could prevent sexual offences against children beforehand, and while a crime is happening, we could judge the situation of the crime intelligently and take swift action to minimize the suffer. And by checking students' attendance and position, guardians could know where their children are in real time and could protect the children from not only sexual offences but also violent crimes against children like kidnapping. The overall system is like follows : RFID Tag for children monitors the approach of offenders. While an offender's RFID tag is approaching, it will transmit the situation and position as the first warning message to the control center and the guardians. When the offender is going far away, it turns to monitoring mode, and if the tag of the child or the offender is taken off or the child and offender stay at one position for 3~5 minutes or longer, then it will consider this as a dangerous situation, then transmit the emergency situations and position as the second warning message to the control center and the guardians, and ask for the dispatch of police to prevent the crime at the initial stage. The RFID module of criminals' electronic bracelets is RFID TAG, and the RFID module for the children is RFID receiver(reader), so wherever the offenders are, if an offender is at a place within 20m from a child, RFID module for children will transmit the situation every certain periods to the control center by the automatic response of the receiver. As for the positioning module, outdoors GPS or mobile communications module(CELL module)is used and UWB, WI-FI based module is used indoors. The sensor is set under the purpose of making it possible to measure the position coordinates even indoors, so that one could send his real time situation and position to the server of central control center. By using the RFID electronic roll book system of educational institutions and safety system installed at home, children's position and situation can be checked. When the child leaves for school, attendance can be checked through the electronic roll book, and when school is over the information is sent to the guardians. And using RFID access control turnstiles installed at the apartment or entrance of the house, the arrival of the children could be checked and the information is transmitted to the guardians. If the student is absent or didn't arrive at home, the information of the child is sent to the central control center from the electronic roll book or access control turnstiles, and look for the position of the child's electronic bracelet using GPS or mobile communications module, then send the information to the guardians and teacher so that they could report to the police immediately if necessary. Central management and control system is built under the purpose of monitoring dangerous situations and guardians' checking. It saves the warning and pattern data to figure out the areas with dangerous situation, and could help introduce crime prevention systems like CCTV with the highest priority. And by DB establishment personal data could be saved, the frequency of first and second warnings made, the terminal ID of the specific child and offender, warning made position, situation (like approaching, taken off of the electronic bracelet, same position for a certain time) and so on could be recorded, and the data is going to be used for preventing crimes. Even though we've already introduced electronic tagging to prevent recurrence of child sexual offences, but the crimes continuously occur. So I suggest this system to prevent crimes beforehand concerning the children's safety. If we make electronic bracelets easy to use and carry, and set the price reasonably so that many children can use, then lots of criminals could be prevented and we can protect the children easily. By preventing criminals before happening, it is going to be a helpful system for our safe life.

An Essay on the Change of Jinju Sword Dance after being designated as an Important Intangible Cultural Asset (<진주검무> 중요무형문화재 지정 이후의 변화에 관한 소고)

  • Lee, Jong Sook
    • Korean Journal of Heritage: History & Science
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    • v.49 no.1
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    • pp.4-21
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    • 2016
  • The purpose of this study is to investigate changes of Jinju Sword Dance, characteristics of the changes, and the current condition of its preservation and succession after the designation as the important intangible cultural property no. 12 in January 16th, 1967. In other words, this study understands the situation which has established the present state of after changes over generations. As of now. the year of 2015, the 3 generation holders have been approved since 1967. In 1967, 8 members of $1^{st}$ generation holders were selected from gisaengs of Gwonbeon. However, the succession training was incomplete due to conflicts among the holders, the deaths of some holders, and economic activities of the individuals. As the need of a pivot for succession training and activities was rising, Seong, Gye-Ok was additionally approved as the $2^{nd}$ generation holder on June $21^{st}$, 1978. Seong, Gye-Ok who had never been a gisaeng had dramatically changed with a lot of new attempts. After the death of Seong, Gye-Ok in 2009, Kim, Tae-Yeon and Yu, Yeong-Hee were approved as the $3^{rd}$ generation holders in February, 2010. Based on the resources including the "Cultural Research Reports of Important Intangible Cultural Properties" in 1966 and videos up to 2014, the changes of the dance and surroundings are as follow. 1. The formation of musical accompaniment has been changed during the 3 generations. In the video of the $1^{st}$ generation(in 1970), the performance lasted about 15 minutes, whereas the performance lasted 25 minutes in the video of the $2^{nd}$ generation. Yumbuldoduri rhythm was considered as Ginyumbul(Sangryeongsan) and played more slowly. The original dance requiring only 15 rhythms was extended to 39 rhythms to provide longer performance time. In the $3^{rd}$ generation, the dance recovered 15 rhythms using the term Ginyumbul. The facts that Yumbul was played for 3 minutes in the $1^{st}$ generation but for 5 minutes in the 3rd generation shows that there was tendency pursuing the slowness from the $2^{nd}$ generation. 2. For the composition of the Dance, the performance included additional 20 rhythms of Ginyumbul and Ah(亞)-shaped formation from the $2^{nd}$ generation. From the $3^{rd}$ generation, the performance excluded the formation which had no traditional base. For the movement of the Dance, the bridge poses of Ggakjittegi and Bangsukdoli have been visibly inflexible. Also, the extention of time value in 1 beat led the Dance less vibrant. 3. At the designation as an important intangible cultural property (in 1967), the swords with rotatable necks were used, whereas the dancers had been using the swords with non-rotatable necks since late 1970s when the $2^{nd}$ generation holder began to used them. The swords in the "Research Reports" (in 1966) was pointy and semilunar, whereas the straight swords are being used currently. The use of the straight swords can be confirmed from the videos after 1970. 4. There is no change in wearing Jeonlib, Jeonbok, and Hansam, whereas the arrangement of Saekdong of Hansam was different from the arrangement shown in the "Research Reports". Also, dancers were considered to begin wearing the navy skirts when the swords with non-rotatable necks began to be used. Those results showed that has been actively changed for 50 years after the designation. The $2^{nd}$ generation holder, Seong, Gye-Ok, was the pivot of the changes. However, , which was already designated as an important intangible cultural property, is considered to be only a victim of the change experiment from the project to restore Gyobang culture in Jinju, and it is a priority to conduct studies with historical legitimacy. First of all, the slowing beat should be emphasized as the main fact to reduce both the liveliness and dynamic beauty of the Dance.

Understanding Human Nobility Epoch, the Prerequisite of the Era of Resolution of Grievances (해원시대를 전제하는 인존시대에 대한 이해)

  • Park, Yong-cheol
    • Journal of the Daesoon Academy of Sciences
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    • v.27
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    • pp.135-169
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    • 2016
  • While examining the religious ideas implied by Jeungsan's Great Works of the Reordering of Universe, we find special ideas which cannot be found in any other religions, and these ideas are presented in diverse ways. Most of all, the representative idea is that of human nobility; a distinctive idea which makes Daesoonjinrihoe different from other religions. Thus, this research focuses on the following questions: when was Human Nobility concretely realized? What kind of organic relationship does human nobility have between the divine world and the world of humanity? In light of the forthcoming Era of Human Nobility, what are some concrete images which can be drawn from the interaction between the realms of heaven and humanity wherein preordinations are plotted in heaven and then carried out by humankind? Prior to formulating my own sense of the subject matter, I consulted 43 previous discussions and dissertations and arranged them chronologically so as to examine their correlation. From these sources and my own insights, I was able to gain a sense of the starting point of the era of human nobility and its tenor. I have found the following problems in previous research on the uniqueness and distinctness of human nobility: ①The conceptual undertones of human nobility have not been adequately gleaned. ②There do not seem to be any dissertations which examine the way in which human nobility is connected with the doctrines of the creative conjunction between yin and yang, the harmonious union of divine beings and human beings, and the resolution of grievances for mutual beneficence. ③In most dissertations, not only is the starting point of the Era of Human Nobility regarded as concurrent with the start of the 50,000 years of earthly paradise in the Later World, but also the point of division between the former world and the later world is widely disputed. ④In-depth and fully realized studies dealing with the subject of human nobility are not easily found. ⑤There is little sense of progression in the research on human nobility because scholars are not sufficiently engage with one another to achieve common consensus. Therefore, in this dissertation, I have provided answers to the problems I discovered in previous research. I have developed my own tenor as follows: ①By giving priority to the Jeongyeong, I have closely investigated the period which divides the Former World and the Later World. Then, I produced a chronological timeline to demonstrate the progression: the Former World → the Era of the Resolution of Grievances → the Later World. This aids in the comprehension of human nobility. ②The Era of Human Nobility was preceeded by the opening of the Era of the Resolution of Grievances of human world which began in 1901. Human nobility is stipulated as a regulatory system for the universe set in motion by the opening the Era of Resolution of Grievances. ③While synthetically examining the aspects of transition which enable the Ear of Human Nobility to be realized, the period to be studied is stipulated as beginning from 1901 and ending at the start of the Later World. The subjects are defined as the flowing from Jeungsan, the first leader of human nobility, to the noble individuals empowered by Dao and the noble populace. In the Era of Human Nobility, studying the transition process by which human nobility is realized requires delving into the resolution of grievances. Although this method is essential to understanding Daesoon ideas, in actuality it does not hinge upon speculative exegetical theorizing but instead it was gained through eisegetical rigor.

Fracture load and marginal fitness of zirconia ceramic coping by design and coloration (유색 및 백색 지르코니아 세라믹 코핑의 코핑 디자인에 따른 파절 하중과 변연 적합성)

  • Shin, Mee-Ran;Kim, Min-Jeong;Oh, Sang-Chun
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.4
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    • pp.406-415
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    • 2009
  • Purpose: The purpose of this study was to compare the marginal fitness and fracture load of the zirconia copings according to the design with different thickness and coloration. Material and methods: The evaluation was based on 80 zirconia copings. Zirconia copings were fabricated in design with different thicknesses using CAD/CAM system (Everset, KAVO dental GmbH, Biberach, Germany). The designs of copings were divided into four groups. The first group consisted of copings with uniform thickness of 0.3 mm. The thickness in the second group was 0.3 mm on the buccal surface and 0.6 mm on the lingual surface. The third group consisted of coping with uniform thickness of 0.6 mm. The thickness in the fourth group was 0.6 mm on the buccal surface and 1mm on the lingual surface. Each group consisted of 10 colored and 10 uncolored copings. Half of the copings (40) processed with a milling system according to the specific design were sent to be given a color (A3) through saturation in special dye by a manufacturing company. Just after sintering, the marginal discrepancies of copings were measured on the buccal, lingual, mesial and distal surfaces of metal die, under a Video Microscope System (sv-35, Sometech, Seoul, Korea) at a magnification of $\times$ 100. It was remeasured after the adjusting of the inner surface. Next, all copings were luted to the metal dies using reinforced cement {GC FujiCEM (GC Corp. Tokyo, Japan)} and mounted on the testing jig in a Universal Testing Machine (Instron 4467, Norwood, MA, USA). The results were analyzed statistically using the one-way ANOVA test. Results: The obtained results were as follow: 1. The measured value of marginal discrepancy right after sintering was the greatest in the contraction of the buccal area in all groups, except for group I2. 2. There was no significant difference of marginal fitness among the groups in the colored zirconia group (P<.05). 3. When the marginal fitness among the groups in the uncolored zirconia group was considered, group II2 had the smallest marginal discrepancy. 4. When the colored and uncolored groups with the same design were compared, there was a significant difference between I1 and II1 groups. In group 2, 3, and 4, the uncolored zirconia had the greatest marginal fitness (P<.05). 5. After adjustment of inner surface, there was no significant difference in the marginal fitness in all groups when color and design of the zirconia coping were compared. 6. The fracture load of CAD/CAM zirconia copings showed significant difference in group 1, 2, 3, and 4. I4 and II4 had the strongest fracture load. 7. When groups with different color and same design were compared, all colored groups showed greater fracture load (P>.05), with no significance. Conclusion: There was difference in the marginal fitness according to the design and coloration of zirconia copings right after sintering, but it was decided that the copings may well be used clinically if the inner surface are adjusted. The copings should be thick enough for the reinforcement of fracture strength. But considering the esthetics of the visible surfaces (labial and buccal surface), the thickness of copings may be a little thin, without giving any significant effect on the fracture strength. This type of design may be considered when giving priority to preservation of tooth or esthetics.

The Role of the Soft Law for Space Debris Mitigation in International Law (국제법상 우주폐기물감축 연성법의 역할에 관한 연구)

  • Kim, Han-Taek
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.2
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    • pp.469-497
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    • 2015
  • In 2009 Iridium 33, a satellite owned by the American Iridium Communications Inc. and Kosmos-2251, a satellite owned by the Russian Space Forces, collided at a speed of 42,120 km/h and an altitude of 789 kilometers above the Taymyr Peninsula in Siberia. NASA estimated that the satellite collision had created approximately 1,000 pieces of debris larger than 10 centimeters, in addition to many smaller ones. By July 2011, the U.S. Space Surveillance Network(SSN) had catalogued over 2,000 large debris fragments. On January 11, 2007 China conducted a test on its anti-satellite missile. A Chinese weather satellite, the FY-1C polar orbit satellite, was destroyed by the missile that was launched using a multistage solid-fuel. The test was unprecedented for having created a record amount of debris. At least 2,317 pieces of trackable size (i.e. of golf ball size or larger) and an estimated 150,000 particles were generated as a result. As far as the Space Treaties such as 1967 Outer Space Treaty, 1968 Rescue Agreement, 1972 Liability Convention, 1975 Registration Convention and 1979 Moon Agreement are concerned, few provisions addressing the space environment and debris in space can be found. In the early years of space exploration dating back to the late 1950s, the focus of international law was on the establishment of a basic set of rules on the activities undertaken by various states in outer space.. Consequently environmental issues, including those of space debris, did not receive the priority they deserve when international space law was originally drafted. As shown in the case of the 1978 "Cosmos 954 Incident" between Canada and USSR, the two parties settled it by the memorandum between two nations not by the Space Treaties to which they are parties. In 1994 the 66th conference of International Law Association(ILA) adopted "International Instrument on the Protection of the Environment from Damage Caused by Space Debris". The Inter-Agency Space Debris Coordination Committee(IADC) issued some guidelines for the space debris which were the basis of "the UN Space Debris Mitigation Guidelines" which had been approved by the Committee on the Peaceful Uses of Outer Space(COPUOS) in its 527th meeting. On December 21 2007 this guideline was approved by UNGA Resolution 62/217. The EU has proposed an "International Code of Conduct for Outer Space Activities" as a transparency and confidence-building measure. It was only in 2010 that the Scientific and Technical Subcommittee began considering as an agenda item the long-term sustainability of outer space. A Working Group on the Long-term Sustainability of Outer Space Activities was established, the objectives of which include identifying areas of concern for the long-term sustainability of outer space activities, proposing measures that could enhance sustainability, and producing voluntary guidelines to reduce risks to long-term sustainability. By this effort "Guidelines on the Long-term Sustainability of Outer Space Activities" are being under consideration. In the case of "Declaration of Legal Principles Governing the Activities of States in the Exp1oration and Use of Outer Space" adopted by UNGA Resolution 1962(XVIII), December 13 1963, the 9 principles proclaimed in that Declaration, although all of them incorporated in the Space Treaties, could be regarded as customary international law binding all states considering the time and opinio juris by the responses of the world. Although the soft law such as resolutions, guidelines are not binding law, there are some provisions which have a fundamentally norm-creating character and customary international law. In November 12 1974 UN General Assembly recalled through a Resolution 3232(XXIX) "Review of the role of International Court of Justice" that the development of international law may be reflected, inter alia, by the declarations and resolutions of the General Assembly which may to that extend be taken into consideration by the judgements of the International Court of Justice. We are expecting COPUOS which gave birth 5 Space Treaties that it could give us binding space debris mitigation measures to be implemented based on space debris mitigation soft law in the near future.

Experiment for Various Soils on Economic Duty of Water in Paddy Fields (각종토성별 경제적용수량 결정시험연구)

  • Hwang, Eun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.11 no.1
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    • pp.1561-1579
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    • 1969
  • In Korea, the duty of water in paddy fields was measured at the Agricultural Experimental Station in Suwon about 60 years ago. After that time some testing has been made in several places, but the key points in its experiment were the water depth of evapo-transpiration. Improved breeds, progress in cultivation and management techniques as well as development of measuring apparatus in recent years have necessitated the review of the duty of water in paddy fields. The necessity of reviewing the conventional methods has become even more important, as no source of information has been made available through survey of water utilization on a soil use basis which requires data on peculiar features of the water depth of evapo-transpiration. For example, the duty of water in paddy field is largely affected by the water depth of evapo-transpiration in connection with the wetted paddy field, whereas in connection with the normal paddy fields without this characteristic the vertical percolation become the predominant factor in measuring the decreasing depth of water. Therefore, it becomes important. that not only the water depth of evapotranspiration but also the vertical percolation process should also be observed in order to arrive at a realistic conclusion. As the vertical percolation has aclose relationship to the height of the underground water, the change of the latter can be measured. As the conclusion of this experiment, the following subjects are indicated. 1. In order to determine the economic duty of water in paddy fields on a basis of varying soil features, the varying soil features in the benifited area should be investigated thoroughly. The water depths of evapo-transpiration(ET) ratio to evaporation in the evaporator(V) on a basis of the varying soil features are as follows: clay loam ET/V = 1.11, loam ET/V = 1.64, sandy loam ET.V = 1.63 2. The decreasing depth of water consists of the water depth of evapotranspiration, the vertical per colation and the percolation of foot path. Among these three, the percolation of foot path can be utilized again. 3. As the result of this experiment, it shows the decreasing depth of water as follows. clay loam 9.3 mm/day, loam 13.5mm/daty, sandy loam 15.3mm/day 4. On a basis of the varying soil features and the height of the underground water, the vertical percolation varies. 5. The change of the vertical percolation on a basis of the varying soil features shows as follows: clay loam $1{\sim}2$ mm/day, loam $2{\sim}3$mm/day, sandy loam $3{\sim}4$mm/day 6. The level of the underground water changes sensibly by priority of clay loam, loam, sandy loam. When it rains, the level of the underground water rises fast and falls down slowly. 7. The level of the underground water changes within the scope of 25cm 8. The transpiration ratio is given in table 8 and their value are as follows: clay loam 168.8, loam 255.6, sandy loam 272.5

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