Recently, the concept of an outrigger damper system with a damper added to the existing outrigger system has been developed and applied for dynamic response control of high-rise buildings. However, the study on the structural characteristics and design method of Outrigger damper system is in the early stages. In this study, a 50 story high - rise building was designed and an outrigger damper system with viscoelastic damper was applied for wind response control. The time history analysis was performed by using the kaimal spectrum to create an artificial wind load for a total of 1,000 seconds at 0.1 second intervals. Analysis of the top horizontal maximum displacement response and acceleration response shows that outrigger damper systems are up to 28.33% and 49.26% more effective than conventional outrigger systems, respectively. Also, it is confirmed that the increase of damping ratio of dampers is effective for dynamic response control. However, since increasing the damping capacity increases the economic burden, it is necessary to select the appropriate stiffness and damping value of the outrigger damper system.

To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.

PURPOSES: Until now, the maintenance of road pavement has mostly involved passive maintenance methods with full maintenance only performed at the end of road life. Recently, there has been growing interest in solving the problem of reflection cracks that occur at joints during application of the overlay method of old concrete pavement. This study was aimed at solving the problem of reflective cracks around expansion joints and at evaluating the durability performance of pavement with interlayer reinforced-composites waterproofing system for concrete overlay. METHODS: This study was conducted to investigate the effect of an interlayer on prevention of reflection cracks and to improve the tensile, compressive, shear, and vertical stresses due to plastic deformation and vehicle cyclic loading. An integrated overlaying layer (5cm or 8cm) was used to evaluate the applicability according to objective indicators. RESULTS and CONCLUSIONS : It was confirmed that cracks did not occur in the section of the line overlaid by the interlayer and that the reflection cracks generated by the action of the lower layer sufficiently absorbed the horizontal movement of the asphalt 5cm pavement overlay. It also suppressed, or at least delayed, the progress of the vertical cracks. The interlayer reinforced composite membrane waterproofing method used in the packing layer, showed through repeated fatigue test results that the accumulated fatigue crack resistance was greater than 120,000 times.

For the setting of control timing, the number of overwintering eggs on host plants and population density of Metcalfa pruinosa nymphs and adults was surveyed in the three peach orchards. According to a survey of the overwintering eggs density (∅2~3㎝, 20㎝ branches) of M. pruinosa on host plants, 221.8 in Mugunghwa trees, 189.3 Oak trees, and 152.7 Acacia trees, and 57.0 Peach showed the number of eggs laid. Examined peach branches within the 50cm (∅1~5cm) was not found population densities of M. pruinosa nymphs and adults, and it was also very low in the sticky trap. The peak density of the adult was highest at 5.4 per trap on August 7 after being first investigated on July 16 in a string wrap survey, and then decreased. In the peach orchard, it is judged that the control of the M. pruinosa is due to be 20 days after the end of the insect hatching, and that distribution of host plants is more important in the outside region than inside region.

Frankliniella occidentalis is a notorious polyphagous crop pest causing tremendous economic loss. It damages flowers and leaves of host plants and also carries severe plant viruses. During last few decades, it has spread to all continents via transport of plant materials. Following extensive use of insecticides to control F. occidentalis, it has developed high level of resistance due to its short life cycle and high reproductive potential. In this study, RNA interference (RNAi)-based bioassay system was developed to find an alternative control measure for insecticide-resistant population of F. occidentalis. A variety of genes involved in various physiological mechanisms were selected for the test of dsRNA potency (tubulin, v-ATPase, amylase, aquaporin etc.). Each bioassay unit made by 3D printing has a leaf disc placed on 150 ㎕ of 50 ng/ul dsRNA solution and 20 thrips. The mortality was checked, and the dsRNA and leaf disc were replaced every 24 h for 72 h. Of the 20 genes tesetd, tubulin, v-ATPase, and aquaporin showed 31, 38, 38 and 45% of corrected mortality at 72 h post-treatment, respectively. This result suggests the potential of these genes as candidate lethal genes for RNAi-based F. occidentalis control system.

A base isolation system is widely used to reduce seismic responses of low-rise buildings. This system cannot be effectively applied to high-rise buildings because the initial stiffness of the high-rise building with the base isolation system maintains almost the same as the building without the base isolation system to set the yield shear force of the base isolation system larger than the design wind load. To solve this problem, the mid-story isolation system was proposed and applied to many buildings. The mid-story isolation system has two major objectives; first to reduce peak story drift and second to reduce peak drift of the isolation story. Usually, these two objectives are in conflict. In this study, a hybrid mid-story isolation system for a tall building is proposed. A MR (magnetorheological) damper was used to develop the hybrid mid-story isolation system. An existing building with mid-story isolation system, that is “Shiodome Sumitomo Building” a high rise building having a large atrium in the lower levels, was used for control performance evaluation of the hybrid mid-story isolation system. Fuzzy logic controller and genetic algorithm were used to develop the control algorithm for the hybrid mid-story isolation system. It can be seen from analytical results that the hybrid mid-story isolation system can provide better control performance than the ordinary mid-story isolation system and the design process developed in this study is useful for preliminary design of the hybrid mid-story isolation system for a tall building.

This study suggests a model of production information system that can reduce manufacturing lead time and uniformize quality by using DNC S/W as a part of constructing production information management system in the industrial field of the existing marine engine block manufacturing companies. Under the effect of development of this system, the NC machine interface device can be installed in the control computer to obtain the quality information of the workpiece in real time so that the time to inspect the process quality and verify the product defect information can be reduced by more than 70%. In addition, the reliability of quality information has been improved and the external credibility has been improved. It took 30 minutes for operator to obtain, analyze and manage the quality information when the existing USB memory is used, but the communication between the NC controller computer and the NC controller in real time was completed to analyze the workpiece within 10 seconds.

This study is intended to look into the effect of construction safety supervision system on risk control and reduction. To achieve this, a survey was carried out to 114 companies in construction, ordering, contract and management. The overall findings were as follows. The effect of construction safety supervision system on risk control and reduction showed that factors of supervision system, supervision cost and supervision method had a positive effect on risk control and reduction. And their perception of the introduction of safety supervision system in construction sites according to process showed that there was a difference between them according to the field of ordering, contract and supervision. There was the biggest difference between owner and contractor in double supervision system, but no difference between them in the perception of risk reduction. These results show that all ordering, contract and supervision are positively needed for the introduction of construction safety supervision. This means that there is a difference between owner and contractor in the perception of process according to system operation. All companies agree to system improvement by the settlement of safety supervision system for the prevention of safety accidents and safe construction, but the systematic complement of safety supervision is the burden of contractor. And there is a big difference between owner and contractor in the perception of responsibility and concern for cost burden.

In this study, a ship motion control system design method is introduced for autonomous ships. Some related research results and technologies for autonomous ships have already been developed and applied to ships. For example, the Norwegian Maritime Authority and the Coastal Administration have signed an agreement that allows to test of autonomous ships in the defined area (port to port). Many countries and industries are pursuing to realize the autonomous vessel in the real world. In this paper, the authors try to develop related technology. As basic research, a ship model of the pilot vessel is developed and physical parameters are identified by experiment and simulations. Using the mathematical ship model, a control system is designed and control performance is evaluated by simulations.

Corrosion inhibitors including calcium hydroxide have been used to prevent corrosion in the pipes for tap water supply. The corrosion index (i.e., Langelier Index) differs by area and water quality. The corrosion indices of the areas studied differed by more than 2.0. The ‘homogenized’ calcium hydroxide was added to the treated water at the K water treatment plant, in order to increase the value of the corrosion index and the concentration of calcium. As the result, the concentration of calcium was increased while the turbidity and pH changed little. The corrosion rate of the tap water with the 'homogenized' calcium hydroxide could be slowed down pretty much. The results suggested that the technology of 'homogenization' of calcium hydroxide can applied to tap water and desalinated water to prevent corrosion in water pipes even in corrosive pipes.

In this study, various physical cleaning methods such as physical washing and osmotic backwash, were conducted to understand membrane fouling properties by employing real secondary wastewater effluent (SWWE). In addition, microfiltration (MF) and ultrafiltration (UF) pretreatments were compared to maximize removal of organic matter and to control membrane fouling efficiently. Organic foulants deposited on the active layer of FO membrane were observed by fouling behavior test. The relationship between concentrations of natural organic matter and membrane fouling was also investigated from the bench-scale FO tests.

Since the encoder and resolver are expensive, it is difficult to apply it as a position sensor of a motor in a real industrial field. Optical position sensors, such as encoders and resolvers, are also difficult to mount because of their size and durability. Therefore, in order to solve these problems, we propose a system that uses a linear motor as a stator and a magnet plate as a mover, and a system that excludes a separate linear scale and uses two linear Hall sensors and permanent magnets to generate a conventional sine wave, A linear motor capable of detecting an absolute position and a movement position of a magnet, a control method thereof, and a technology development that can reduce a production cost by developing a position control system using a magnet mover that can improve stability and reliability.

세월호 사고 이후 내항선 안전관리분야에서의 가장 큰 변화는 해사안전감독관 제도의 도입이라 할 수 있다. 이 제도의 도입으로 내항여객선의 안전관리는 운항관리자와 해양경찰로부터 운항관리자와 새로이 도입된 해사안전감독관으로 변경되었다. 또한 내항화물선의 안전관리도 선박검사관으로부터 해사안전감독관과 선박검사관에 의한 안전관리의 체계로 전환되었다. 그러나 새로이 도입된 이 제도는 전문임기제에 따른 감독관의 신분상의 불안으로 인한 업무연속성 부족, 감독대상의 현실을 무시한 감독관의 자격요건 설정, 내항화물선에 대한 심사와 지도·감독기관의 분리로 인한 업무혼선 및 감항성 확보를 위한 항행정지 개선명령 분야의 한계 등에 대한 문제점이 여전히 남아 있다. 내항선의 안전관리를 보다 강화하기 위해서는 내항선 안전관리 업무를 실질적으로 수행하고 있는 해사안전 감독관 제도의 정착이 필수적이라 아니할 수 없다. 따라서 이러한 문제점을 개선하기 위해서는, 내항화물선에 대해서 통합된 단일기관에 의한 체계적인 안전관리가 이루어져야 하며, 전문임기제인 감독관의 신분상의 제약에 대한 개선이 동시에 이루어져야 한다. 또한 항행정지 개선명령의 분야를 확대하고, 선장·기관장 및 국제선급의 검사원 경험자 위주로 감독관의 자격을 강화해서 보다 체계적이고 실질적인 내항선의 안전관리가 되도록 해야 할 것이다.

With the concerns of global climate change, the significant changes in rainfall patterns have aggravated the occurrence of pollutants from agricultural uplands. Heavy and intensive rainfalls have rinsed a variety of pollutants off the land, sending them into the neighboring water environments which further causes water pollution problems. Recently, the application of PAM(Polyacrylamide) in agricultural lands has gotten much attention for soil conditioning. Therefore, this study aimed to develop the automatic control system applying the chemical flocculant, liquid PAM in order to flocculate the suspended solids and deposit at the bottom of farmland water channel, so eventually minimize the amount of non-point pollutants discharged into receiving water. The optimum feed rate for liquid PAM was calculated through the experiment in artificial water channel and applied to the control system. As the results of the performance test of the automatic turbid water control system installed in the sloped field, the range of turbidity reduction rate was 25 to 33% with the average turbidity of 292 to 498 NTU in water channel.