• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.866-871
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• 2006

The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

• Korean Security Journal
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• no.22
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• pp.113-144
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• 2010

Bioterrorism is becoming more attractive to terrorist groups owing to the dramatic increase in the utility and lethality of biological weapons in line with today's cutting-edge biological science and technology. The Republic of Korea is facing both internal and external terrorist threats, as well as the possible biological warfare by North Korea. Therefore, it is essential to establish an effective bioterrorism response system in the ROK. In order to come up with the adequate response system for the ROK, an in-depth study has been conducted on the current bioterrorism response system of the U.S. whose preparedness is considered relatively adamant. As a result, the following facts have been found: (1)the legislation with regard to bioterrorism has been established or amended according to the current situation in the U.S., (2)the counter terrorism activities have been integrated with the Department of the Homeland Security as the central agency in order to maximize the national CT capacity, (3)Specific procedures and instructions to cope with bioterrorism have been made into manuals so as to enhance the working-level response capabilities. Next, the analysis on the ROK's bioterrorism response system has been performed in various categories, including the legislation system, task role distribution, cooperative relations, and resource application. It turned out that the ROK's legislation basis is relatively weak and it lacks the apparatus to integrate the bioterrorism response activities on the national level. The shortage of the adequate response facilities and resources, as well as the poor management of manpower have also emerged as problems that hinder the effective CT implementations. Through an analytical and comparative study of the U.S. and the ROK systems, this paper presents several ways to ameliorate improve the current system in the ROK as follows: (1)establish the anti-terrorism law, which would be the basic legal basis for the bioterrorism-related matters; and make revisions to the disaster-related legislation, relevant to bioterrorism response activities, (2)establish an integrated body that has a powerful authority to coordinate the relevant CT agencies; and converge the decentralized functions to maximize the overall response capacity, (3)install the laboratories with a high biosafety level and secure enough of the strategic medical stock-pile, (4)enhance the ability of the inexperienced response personnel by providing with a manual that has detailed instructions.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.299-305
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• 2018

Perception refers to the process of acquiring all the information about the environment through various sensory organs such as the visual, auditory, tactile, and olfactory senses and integrating and interpreting the information transmitted to the brain. The ability to use these perceptions efficiently is called perceptual skill, and perceptual skill is an important factor for improving performance in the field of sports. As a result, many researchers have developed various perceptual training programs to maximize these perceptual skills while they have also progressed on attempting to verify their effects. The perceptual skill training introduced in this study is a training method that focuses on visual perception and is a training method that is applied in the United States and Europe. to improve sports performance. As a result of carrying out the perceptual skills training based on the kicker's important clue (the kicker's hip - the angle of the body and foot before kicking) to the goalkeeper in the situation of a soccer penalty kick improved the ability of predicting the direction of the ball while even in tennis, carrying out the perceptual skills training based on the server's important clue (position, ball, racket) improved the accuracy of the ability to predict in the direction of serve. Recently, there have been numerous research studies that were carried out on such perceptual skills training, but the number of studies conducted are insufficient, especially in Korea where research studies on perceptual training seem to be in a relatively neglected state. In addition, extensive studies need to be carried out to investigate whether the improvement of perceptual skills in the laboratory situation can be transitioned to an actual performance situation. Therefore, in order to elevate sports performance, researchers need to examine the perceptual training program's extent of necessity as well as the research direction regarding its effects.

• Journal of Advanced Navigation Technology
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• v.3 no.2
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• pp.108-119
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• 1999

In recent, there has been remarkable progress in the field of GPS applications. In a few years, an appreciable number of aircraft will adopt GPS as a landing guidance system because GPS is more economic, more reliable and more accurate than any other aviation systems. In this respect, we have performed several helicopter landing flight tests based on the real-time DGPS system made in SNUGL (Seoul National University GPS Laboratory). From the experimental results, we found several problems Which should be fixed to adopt DGPS as a aircraft landing guidance system. In this paper, we will introduce the problems found in tests and also suggest modifications to solve the problems. Our modifications can be classified into three parts. The first is about the attitude determination with single GPS antenna. The second deals with the cockpit display module. The display was devised to integrate the Instrument Landing System(ILS) with tunnel-the-sky using virtual reality. With the display, pilot can achieve more safe landings. The last part is the digital map. We inserted digital map into our system and put direction indicator on the map using position information from GPS. It is very useful for pilot to find airports even in bad weather. Using the newly designed DGPS landing system, we conducted flight test at Kimhae International Airport, Pusan, Korea. It was successful! Our system can also satisfy Category-I criterion for aircraft landing approach and determine attitude angle with a high level of reliability. It is supported by video materials.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.7
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• pp.1021-1029
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• 2018

The marine buoys are operated in various domains, which are navigation route and danger maker, weather and environment monitoring, military strategical element, etc. If the marine buoy is damaged, there consumes many cost and time for recovery or replacement, because of severe environmental condition, and causes a risk possibility of secondary accident. In this paper, we developed an active monitoring and approach alarm providing system using trail cameras and AIS for protection for the marine buoys. To do this, we analyzed existing researches and similar systems, extracted requirements for enhancement, and designed the system architecture that applied the enhanced elements. The main considerations of system enhancement are: integration of AIS and trail cameras, adopting of phased alarm technique by approaching ships, applying of selective communication module, conducting the image processing of ships for providing alarm, and applying thermal cameras. After that, we developed the system using designed architecture and verified effectiveness of the system based on laboratory or field-level tests.

• Journal of KIISE:Information Networking
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• v.30 no.5
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• pp.656-667
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• 2003

Congestion control is a key task in reliable multicast along with error control. However, existing tree-based congestion control schemes such as MTCP and TRAMCC are designed for one-to-many reliable multicast and have some drawbacks when they are used for many-to-many reliable multicast. We propose an efficient congestion control mechanism, TMRCC, for tree-based many-to-many reliable multicast protocols. The proposed scheme is based on the congestion windowing mechanism and a rate controller is used in addition. The feedback for error recovery is exploited for congestion control as well to minimize the overhead at the receivers. The ACK timer and the NACK timers are set dynamically reflecting the network condition changes. The rate regulation algorithm in the proposed scheme is designed to help the flows sharing the same link to achieve the fair share quickly The performance of the proposed scheme is evaluated using ns-2. The simulation results show that the proposed scheme outperforms TRAMCC in terms of intra- session fairness and shows good level of responsiveness, TCP-friendliness, and scalability. In addition, we implemented the proposed scheme by integrating with GAM that is one of many-to-many reliable multicast protocols and evaluated the performance in a laboratory-wide testbed.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.163-170
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• 2022

There is a continuous rise in the commercialization of living modified (LM) organisms worldwide. While LM plants have not yet been cultivated in South Korea, research, development, import of products, and registration of related research facilities are progressing. LM plants should be tested in greenhouses and fields during development. Furthermore, environmental risk assessment and safety management should be performed before their release into the environment. Research on LM plant development is conducted in laboratories as well as confined greenhouses and fields. Safety management regulations are provided as combination standards for the LMO Act in each research district. The accidental release of the LM petunia in Japan was a significant incident related to LM plant research. It implies that normal plants within the distance of crossing should be regarded as LM plants. In the United States, LM creeping bentgrass was released into the environment, thus necessitating the establishment of stringent measures to prevent the scattering of LM plant seeds by wind or other mediums. In South Korea, LM Zoysia and LM cotton were released through rainwater. Therefore, safety measures that prevent LM seed mixing and plant vegetative propagules escaping into the environment via rainwater must be established. Preventing the dispersal of unapproved LM plants requires significant time, expenditure, and effort. Researchers should first identify the impact of LM plants on the ecosystem, and steps to avert their environmental release must be implemented.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.255-266
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• 2020

This study conducted a systematic literature review on nursing students to find out the types and composition of patient safety-related education programs. The research was conducted systematically using PRISMA. The patient was a nursing college student, and the intervention was patient safety education. The outcome was either numerical or descriptive reports of the results measured using the tool. The types of research were carried out including randomized design, quasi-experimental design, one-group design, survey and qualitative research. The paper was searched through Medline, Embases, CINAHL, DBpia, Riss and KISS. A total of 2,468 papers were searched in the search results, and nine papers were used for analysis as a result of extracting data according to PICO. The characteristics of patient safety education of nursing college students were classified according to the teaching method, period, result variables and measurement tools. As a result, patient safety education consisted of a variety of subjects, and was being taught through lectures, clinical practice, laboratories, and simulations. The period of education also varied. The resulting variables were mainly checked for knowledge, attitude, and skill, and the tools used to measure them varied. Patient safety education for nursing college students was conducted through various topics, methods and periods at home and abroad. Therefore, continuous research is needed to establish consistent and integrated patient safety education in educational institutions and working institutions to produce nursing personnel with patient safety capabilities.

• Journal of The Korean Association For Science Education
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• v.26 no.7
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• pp.775-789
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• 2006

The purpose of this study was to analyze the relevance of the school science contents that have been implemented for the 7-10th grade students in Korea since 2001. To fulfill the purpose of the study, we 1) analyzed the 7th national science curriculum of Korea, California science standards, the national science curriculum of England, Japanese national science curriculum, and current Korean and Japanese science textbooks, 2) conducted a nationwide survey in order to gather opinions from students, teachers, and science specialists. The main findings of this research were as follows: First, the number of topics presented at each grade level should be reduced and similar topics and themes should be integrated for students' deeper understanding. Second, science contents were excessive compared to the allotted teaching time and to foreign countries. Thus, the excessive overlapping and repetition of science contents should be avoided among the primary, middle and high school level, and the number of science concepts and activities should be reduced to an appropriate level considering time allotment for science classes, teachers' workload, laboratory conditions, etc. Third, to cope with the decreasing students' understanding and interests in science as school level and school year goes up, the science curriculum and textbooks should be developed to allow for student to learn science concepts by solving problems confronted in their daily lives. Fourth, a differentiated curriculum such as in-depth and supplementary course should be described not in science contents, but in teaching and learning strategy.

• Journal of The Korean Association For Science Education
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• v.38 no.6
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• pp.885-899
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• 2018

As 'Science Inquiry Experiment' is newly introduced in the high school curriculum, where inquiry and experiment oriented education is insufficient, this study aims to analyze teacher's practice of 'Science Inquiry Experiment' in depth and identify contradictions during its process in the perspective of Cultural Historical Activity Theory. The research participant is teacher SHIN who is exclusively responsible for Science Inquiry Experiment. Starting with reflection on the practice of Science Inquiry Experiment class conducted in the first semester, interviews with participants, participatory observation and local materials were used during the 2nd semester's Science Inquiry Experiment class. A descriptive analysis of the teacher SHIN's practice of Science Inquiry Experiment was carried out and the contradictions in the activity system of the teacher SHIN were identified. The result reveals that in the overall practice of teaching Integrated Science and Science Inquiry Experiment, there were contradictions between teacher SHIN's recognition about cooperation(subject) and shared responsibility with other teachers(division of labor), and between teacher SHIN's recognition about the subjects(subject) and contrasting contents in teacher training courses(community). In the practice of teaching Science Inquiry Experiment, there were specific contradictions between teacher SHIN's recognition about the subject(subject) and time of job assignment(rule), between experimental activities(object) and experimental tools(tool), and between purpose of the subject(object) and directions about assessment(rule). These contradictions directly or indirectly influence the practice of teaching Science Inquiry Experiment. There needs to be support for constructing an activity system capable of supporting and promoting teachers' practice of Science Inquiry Experiment, and we made several suggestions to resolve the problems.