• The Journal of Korean Association of Computer Education
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• v.14 no.5
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• pp.9-18
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• 2011

Compiler development projects, which are designed and taught in compiler course, allow students to practice and absorb valuable amount of experience and techniques in developing compilers. However, both instructors and students face difficulties as they are often limited by insufficient hands-on time during course of an academic year along with a relatively high level of technologies involved when dealing with compilers. As well, most compiler's target systems use interpreter-based technologies which are rather limited in drawing student's attention. As a result compiler courses often end up being more of a theoretical course than practical. This paper presents a new integrated development environment (IDE) that will help overcome aforementioned difficulties and allow students to obtain both theoretical and practical knowledge more efficiently. The development environment includes a reference compiler with $Mindstorms^{(R)}$ NXT Robots as the target system, compiler development tool, target language test tool, and code generation visualizer. It is developed as a plug-in for the popular Eclipse IDE which enables easy access and great expandability. This integrated development environment allows students to understand compilers better and start their development faster.

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.322-330
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• 2020

This study investigates the far-field noise from three Falcon 9 vehicle launches from Vandenberg Air Force Base, CA, USA, as measured from the same location within the nearby community of Lompoc. The overall sound pressure levels for the three launches are shown to be similar, but some differences in the early launch period are thought to be weather-related. The peak directivity angle in overall level is approximately 65 deg, which is consistent with horizontally-fired, static rocket data. For the third launch, waveforms and spectra are analyzed for different events during the launch sequence. The measured spectral bandwidth decreases with time, but spectral levels remain above the ambient noise throughout the main-engine firing. Additionally, late-launch phenomena observed in the data appear to be correlated with main-engine cutoff and second-stage engine start.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.564-570
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• 2014

This paper propose a method to detect and track a human face using depth information as well as color images for detection of drowsy driving. It consists of a face detection procedure and a face tracking procedure. The face detection procedure basically uses the Adaboost method which shows the best performance so far. But it restricts the area to be searched as the region where the face is highly possible to exist. The face detected in the detection procedure is used as the template to start the face tracking procedure. The experimental results showed that the proposed detection method takes only about 23 % of the execution time of the existing method. In all the cases except a special one, the tracking error ratio is as low as about 1 %.

• Hwankyungkyoyuk
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• v.20 no.1
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• pp.19-27
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• 2007

This study was intended to answer the question, 'What kinds of effects will be aroused by experiential learning for environment based on living area?'. Experiential learning for environment was operated to 17 elementary school students in 4th grade in Kyeong-san city. The results were drawn analyzing the mind map for the changes of environmental consciousness before and after learning, and they are as below. First, it had an effect to change the meaning association of the relationship between 'river and me'. Meaning association was 'river-a thing' before experiential learning, but it was developed as 'river-a thing-me' after learning. This means that students expanded understanding of the world that they were belonging and self-spatialization was promoted. The expansion of meaning association would be a start point and a method to promote their segmentation for each student. Second, students could self-directly modify misconception and preconception after experiential learning. It showed that students could find meanings in the world that they were belonging by experiential learning for environment, and misconception obtained by concept learning without actual situation could be revised through the truth recognition in meanings, and student could see what things displayed. Therefore preconception would be corrected. Of course, everything would not be completed by just one time of experiential learning, and consistent experience learning should be operated. Third, experiential learning promoted the change of sensitivity. Students had shallow sensitivity, which appeared in the relation with things, since having learned only inside of class without a direct observation. However their sensitivity could be increased by experiencing specific things. Fourth, there was the change of classification recognition. Students found properties of things with a direct observation. It raised their ability to classify things, and to understand an individual thing in 'a class'.

• KSBB Journal
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• v.21 no.3
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• pp.188-193
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• 2006

A new type of biofilter, a rotating drum biotrickling filter(RDBF), was developed and operated for the removal of styrene from industrial waste gas. The porous polyurethane foam sheet was used as a packing materials for the RDBF and a pure culture of Gram-positive bacterium Brevibacillus sp. SP1 was used as an inoculum. The reactor showed a short start-up period of 18 days, during which uniform biofilms were developed on the packing. During a steady operation at an incoming styrene concentration of $200ppm_v$ and a retention time of 0.5 min, a high and stable removal of styrene over 95% was observed. The maximum elimination capacity was estimated to be $125g/m^3{\cdot}hr$. The outstanding performance was attributed to an efficient gas-liquid mass transfer and the appropriate supply of nutrient solution to the biofilm microorganisms on the packing by the rotation of the drum.

• Journal of Korean Foot and Ankle Society
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• v.18 no.3
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• pp.115-118
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• 2014

Purpose: The purpose of this study is to report on the result of repairing Achilles tendon using absorbable suture under nerve block. Materials and Methods: We retrospectively reviewed 20 patients with acute Achilles tendon rupture who were followed up for at least six months after the operation. We repaired Achilles tendon using two absorbable sutures using the Krackow technique for the proximal stump and the Kessler technique for the distal stump. A programmed postoperative management including non-weight bearing with a short leg cast for four weeks after the operation was applied for all patients. We evaluated clinical results using American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS) for satisfaction, range of motion of ankle, functional recovery rate, and the starting time of single heel raise. Results: The mean VAS score for satisfaction and AOFAS score was 9.2 and 93.0, respectively. The affected ankle showed a mean dorsiflexion rate of 90% and plantar-flexion rate of 94% compared to the uninjured side. The single heel raise could start at a mean of 3.5 months after the operation. Conclusion: Treatment of Achilles tendon rupture with absorbable suture material using the hybrid suture technique of proximal Krackow and distal Kessler showed sufficient stability and minimal chronic inflammatory reaction.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.687-694
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• 2020

SDN and NFV are next-generation network technologies, and cloud, such as data centers, campuses, and large companies, has been established, or is actively applied by service-oriented communication companies. In particular, the Defense Integrated Data Center will be a prime example for military applications. In order for the Defense Integrated Data Center (DIDC) to become an intelligent center, it is accelerating the promotion of the "Smart Defense Integrated Data Center", which applied the latest information and communication technology (ICT). At the time of the establishment of DIDC, it plans to start building infrastructure such as cloud services at around 30% level, and expand D-Cloud to 75% through 'Cloud First'. In addition, the introduction of SDN/NFV will reduce the operation cost and manpower of DIDC, strengthen the ability to efficiently use information resources and cyber information protection systems, and increase flexibility and agility in using each system to improve efficiency in defense management in the future. Therefore, we will discuss the justification and expected effects of SDN/NFV introduction, focusing on DIDC.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1299-1304
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• 2011

A wind turbine (WT) should be shut down as fast as possible to minimize its own damage in a storm-driven situation. Shutdown of a large wind farm requires a power grid to have a ramp-up capability large enough to balance between generation and consumption of electrical energy. This paper proposes a supervised shutdown algorithm of a wind farm to meet a required ramp-down rate in a grid code in the case of a storm-driven situation. The information on the speed and the direction of wind is measured at a wind mast (WM) installed around a wind farm. If the wind speed exceeds a cut-out speed, the number of WTs to be shut down simultaneously is decided to meet a required ramp-down rate of a grid-code. Arrival times to each WT from the WM are calculated and sorted in the order of time. Then a sequence of groups is generated. The shutdown start/end times of each group are decided to avoid superposition between adjacent two groups. The performance of the proposed shutdown algorithm is verified under various storm scenarios. Results indicate that the proposed algorithm can not only protect the wind farm in the case of a storm-driven situation but also meet the required ramp-down rate. In addition, the algorithm can produce more energy than that of a conventional shutdown algorithm.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.135-143
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• 2012

Arterial stiffness is causing the serious problems for human who is suffered from hypertension and metabolic syndrome. So it is important that measure the arterial stiffness for early prevention. Many researches point out that pulse wave velocity(PWV) is the reliable and simple method to predict arterial stiffness. In this paper, we developed the sensing parts that detect the pulse wave and ECG by using piezoelectric film and conductive textile with elastic band. Our system could detect 3ch pulse wave and ECG. Simultaneously, our algorithm extracts the features for calculating the delays among pulse waves. The delays are the significant parameter to estimate PWV, thus we design the experiment for evaluating the performance of our sensing parts. The reference is PP-1000(HanByul Meditech, Korea) that is good for performance evaluation. As a result, the start point of the pulse wave was the most reliable feature for comparing with PP-1000(r=0.691, P=0.00). The results between two operators showed that there is only a slight difference in the reproducibility of the devices. In conclusion, we assume that the suggested sensor could be more comfortable and faithful method for arterial stiffness.

• Environmental Analysis Health and Toxicology
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• v.25 no.3
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• pp.241-251
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• 2010

Crucian carp (Carassius auratus) has been used as the sentinel species for POPs (Persistent Organic Pollutants) monitoring in aquatic environment. However, there is little information for dioxin toxicity and especially, early life stage toxicity in crucian carp have been never carried out. In this study, we investigated several toxic effects for 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in fertilized egg obtained by natural fertilization from crucian carp. The embryos at 3 h post-fertilization (hpf) were treated with 0.039, 0.156, 0.625, and 2.5 (${\mu}g/L$) TCDD by waterborne exposure for 60 minutes and changed with fresh water 2 times per day. Fertilized eggs started hatching at 51 hpf and TCDD exposed embryo showed decrease of hatching rate in a dose-dependent manner at 75 hpf. Pericardial edema was continuously observed in larvae exposed to TCDD from hatching start time (51 hpf), followed by the onset of mortality. In addition, AhR-related gene, CYP1A was clearly increased by TCDD in a dose dependent manner. These results indicated that fertilized eggs obtained from crucian carp have the TCDD related gene regulation and a distinct TCDD developmental toxicity syndrome by TCDD exposure. Therefore, we suggested that early life stage test in crucian carp could be used as test methods on dioxins toxicity.