• Clinics in Shoulder and Elbow
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• v.15 no.2
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• pp.123-129
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• 2012

Objective: To evaluate if acromial locking in hook plate is necessary for surgical treatment of acromioclavicular dislocation by compare Wolter plate and AO hook plate. Methods: Seventy one patients who have Rockwood type III to V acromioclavicular joint dislocation treated with AO hook plate and Wolter plate were involved. Among them, 39 patients were treated with Wolter hook plate and 32 patients with AO hook plate. The Constant-Murley score and the range of motion of shoulder joint were measured on postoperative 1st ,$3^{rd}$, $6^{th}$ and $12^{th}$ months, and the radiological complications involving plate and bone were investigated. Results: Constant-Murley score of postoperative one year were $83.2{\pm}6.8$ in AO hook plate group and $85.2{\pm}5.3$ in Wolter plate group without statistical difference (p<0.05). Faster recover of forward elevation and external rotation were examined in Wolter plate group at first and third months after surgery than those of AO hook plate group, but there were no significant difference between after six months or later after surgery. Four cases of loosen or broken screws and one case of pull-out of plate were found in Wolter plate group. Seven cases of subacromial bony erosion and one periprosthetic fracture were found in AO hook plate group. Conclusion: Although clinical outcomes of both two methods were same, no matter if acromial locking system was or not. More radiological complication of plate and bone were found in AO hook plate than that of Wolter plate. However also had disadvantage like larger incision during surgery.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.86-88
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• 2017

The digital door lock is an electronic door lock that uses a password system and has the function of automatically locking the door when the door is closed, thus eliminating the worry about the door lock. As the technology has gradually developed, various authentication technologies such as semiconductor key system, RFID, and fingerprint recognition have been introduced. However, there is a danger of copying the door lock key, and there are password stealing and infringement. In this paper, we develop a remote control system that can unlock or open a smartphone to supplement the user's risk. The system you are going to develop can use WiFi to check if the door is locked or open on your smartphone, and you can lock or unlock the door remotely.

• Journal of the Optical Society of Korea
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• v.17 no.1
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• pp.103-108
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• 2013

The operation of a Doppler wind LIDAR in a mobile environment is very sensitive to shocks and vibrations, which can cause critical failures such as misalignment of the optical path and damage to optical components. To be able to stabilize the LIDAR and to perform wind field measurements in motion, a shock absorption and vibration isolation system was designed and implemented. The performance of the vehicle-mounted Doppler wind LIDAR was tested in motion, first in a circular test route with a diameter of about 30 m and later in regular expressway traffic. The vibration isolation efficiency of the system was found to be higher than 82% in the main vibration area and shock dynamic deflection was smaller than maximal deflection of the isolator. The stability of the laser locking frequency in the same mobile environment before and after the vibration isolation system installation was also found to be greatly improved. The reliability of the vibration isolation system was confirmed by good results of the analysis of the LIDAR data, in particular the plane position indicator of the line of sight velocity and the wind profile.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.475-481
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• 2018

In this study, the safety and effectiveness of ope cutter, developed to prevent frequent accident propeller windingness at sea. First, we calculated the bolt strength of the three types of rope cutting devices used in the experiment and the torsional stresses on the shafting system theoretical equation and the finite element method. As a result, the bolts used in the rope cutter confirmed from the viewpoint of safety life design and fail safe design. Also, safety satisfactory because of the small effect on the shaft system when locking up. Experiments were carried out to cut ropes and fishing nets from the sea using the ships equipped with three types of rope cutters verified to be safe. As a result, ropes of 20 to 50 mm in thickness were generally cut. It was found that the cutting efficiency of a rope cutter attached to shafting decreased when cutting thick ropes.

• Journal of the Korea Furniture Society
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• v.19 no.3
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• pp.193-202
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• 2008

In order to occupy educational furniture market that grows by the day and to meet demands for alternative product for the current market, this study took business features and productivity of Sinil Furniture Co into consideration, and developed computer desk for education by group, which is new among educational furniture. The scope of the study ranges from data research based on design process into creation of prototype. By improving the condition where, despite that electrically-powered computer desk for anti-theft system is high priced, it sees frequent malfunction, the study suggested low-priced, non- electrically-powered anti-theft system which has more solid structure. Furthermore, in order for the user to be more free and comfortable while studying on it, it differentiates from other products by locating PC main body to the back of the monitor and lowering it below the altitude of monitor to prevent it from interfering with studies. We've made the higher board of the desk in a soft curved-shape in order to lessen the stress from studying. And as space for the monitor's lower mount was decreased, we've put the lower mount below the higher board; so that lacking space can be recovered while functioning as anti-theft system. Moreover, we've covered the PC main body with steel cover so that it would add color and formal luxuriousness to the appearance of the desk. Considering ease of mobility and productivity, knock-down system was introduced.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.298-302
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• 2016

Currently, logistics are in small quantities and in diverse forms, and the amounts are continuously increasing. Railway logistics however are losing their market share every year mainly due to low operation speed and loading time, which means the trucks are covering the most of the freights. In order to solve these situations, this paper proposed the high speed freight train as working multi-modality with other modes to make effective transshipment. The high speed freight train has maximum operation speed of 300km/h and electric power to run centralized power supply. There are large dual door system, bogie system covering fluctuating load of 15[ton], automatic loading device, ULD(unit load device) bed and ULD locking system in this freight rolling stock. We calculated the performance of powering and braking capacity for this train and proposed how many vehicles are composed of train set. The results in this paper can help to make a decision to define the technical specification of High-speed freight train for the efficiency of rail freight service.

• Korean Membrane Journal
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• v.10 no.1
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• pp.13-19
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• 2008

Water softening is a very promising field for membranes and especially ultra low pressure membranes. Nanofiltration membranes based on pore-filling technology was prepared by using a new technique: the in-situ cross-linking. This route involves introducing a pre-formed polymer into the pores of a host membrane and then locking the polymer in the pores by in-situ cross-linking with an appropriate reagent. By this way, it is possible to make robust and competitive, pore-filled, anion-exchange membranes with excellent control over the properties of the incorporated gel without affecting the host membrane. In this paper, the possibilities of tuning such membranes for ultra low pressure water softening was examined by altering pore-filling chemistry (by changing cross-linking and aminating reagents). The results showed that tuning the chemistry of the pore-filling has important effects. In particularly, it had been shown that the correct selection of cross-linking reagent was not only essential to get pore-filled membranes but it could control their properties. Moreover, the aminating reagent could improve membrane performance. It was found that an increase in hydrophobicity could improve the Darcy permeability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.2 s.332
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• pp.23-30
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• 2005

This paper describes a DLL(delay locked loop)-based multi-clock generator having the lower active stand-by power as well as a fast relocking after re-activating the DLL. for low power and high speed VLSI chip. It enables a frequency multiplication using frequency multiplier scheme and produces output clocks with 50:50 duty-ratio regardless of the duty-ratio of system clock. Also, digital control scheme using DAC enables a fast relocking operation after exiting a standby-mode of the clock system which was obtained by storing analog locking information as digital codes in a register block. Also, for a clock multiplication, it has a feed-forward duty correction scheme using multiphase and phase mixing corrects a duty-error of system clock without requiring additional time. In this paper, the proposed DLL-based multi-clock generator can provides a synchronous clock to an external clock for I/O data communications and multiple clocks of slow and high speed operations for various IPs. The proposed DLL-based multi-clock generator was designed by the area of $1796{\mu}m\times654{\mu}m$ using $0.35-{\mu}m$ CMOS process and has $75MHz\~550MHz$ lock-range and maximum multiplication frequency of 800 MHz below 20psec static skew at 2.3v supply voltage.

• Convergence Security Journal
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• v.16 no.2
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• pp.71-76
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• 2016

As an extreme-type crime caused by social anxiety and economic hardship, firearm accidents recently rising as a serious social problem are gradually increasing the national anxiety as people start realizing that Korea is no more a safety zone for firearm accidents. In order to improve it, the police and academia are presenting measures through the suggestion of diverse policies and also change of system. However, there are not sufficient researches in the aspect of technology while some people argue that they cannot become fundamental alternatives on top of its effectiveness issue. Thus, this study has suggested a more effective firearms safety control system in the aspect of technology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.1-7
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• 2011

A performance delivers the contents and feeling through human bodies and stage settings in the limited space of a stage. Among the stage settings, the lighting creates overall atmospheres effectively according to the situations of the performance such as a time flow, a change of seasons, an expression of the mental state of the performer. As the LED lighting is used more widely, the number and the size of the lighting is being decreased, which makes it possible for various devices to be used. However, just as conventional lighting devices, most of them are fixed. So it is difficult to use them at a blind spot and to replace them. To solve this problem, this article suggests a system which replaces lighting automatically and moves. As it can moved to a spot we want on a rail, and the lighting system can be replaced by itself, it can have various lighting effects, increasing the effectiveness of the performance. Additionally, it can also decrease the danger of a worker operating the lighting device located at a high place. At the mock-up experiment, its mobility and stability on a rail were tested using the wheel of the Modular Robot.