• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.297-306
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• 2007

Distraction osteogenesis was pioneered by Ilizarov in the treatment of injured extremities. Its subsequent application to Oral and Maxillofacial Surgery has opened a new chapter in the treatment of facial deformity. Careful monitoring of the period of distraction and consolidation of the callus is important and has been well described. Complications, such as infection, haematoma and premature ossification, are difficult to diagnose and can compromise the outcome after the surgery. Too slow rate of distraction results in premature fusion of cortices and too rapid information of bone 'cyst' within the callus distraction. I experienced 2 patients of congenital unilateral mandibular hypoplasia, so called Hemifacial Microsomia. After distraction surgery, I evaluated callus formation of mandibular distraction with Ultrasound Sonography during distraction and consolidation period. Plain radiography, although it enables accurate measurement of the distraction gap, did not give sufficient detail to allow assessment of early stages of bone formation, But, ultrasound monitoring could enable continuous monitoring of the distraction gap without exposure to ionizing radiation and allow detection of fine detail, which may influence manipulation of the callus.

• Journal of Electrochemical Science and Technology
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• v.11 no.4
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• pp.379-383
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• 2020

The novel voltammetry using a semi-circular potential wave for quasi-reversible charge transfer system on electrode is theoretically investigated. Compared with conventional voltammetry based on linear sweep such as linear sweep voltammetry (LSV), semi-circular potential sweep voltammetry (SCV) may decrease the charging current outside the center of potential range and increase the faradaic current at the midpoint due to variable scan rate. In this paper, we investigate the system based on macroelectrode where simple 1 dimensional (1 D) diffusion system is valid with various charge transfer rate constant (k₀). In order to observe the amplification at midpoint, voltammetric response with different midpoint ranging from -200 mV to 200 mV are studied. SCVs shows both the shift of peak potential and the amplification of peak current for quasi-reversible electrode reaction while only higher peak current is observed for reversible reaction. Moreover, the higher current at midpoint enable the amplification of current at low overpotential region which may assist the determination of onset potential as a figure-of-merit in electrocatalyst.

• Journal of The Korean Astronomical Society
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• v.47 no.6
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• pp.279-291
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• 2014

I show that the WFIRST microlensing survey will enable detection and precision orbit determination of Kuiper Belt Objects (KBOs) down to $H_{vega}=28.2$ over an effective area of ${\sim}17deg^2$. Typical fractional period errors will be ${\sim}1.5%{\times}10^{0.4(H-28.2)}$ with similar errors in other parameters for roughly 5000 KBOs. Binary companions to detected KBOs can be detected to even fainter limits, $H_{vega}=29$, corresponding to R~30.5 and effective diameters D~7 km. For KBOs H~23, binary companions can be found with separations down to 10 mas. This will provide an unprecedented probe of orbital resonance and KBO mass measurements. More than a thousand stellar occultations by KBOs can be combined to determine the mean size as a function of KBO magnitude down to H~25. Current ground-based microlensing surveys can make a significant start on finding and characterizing KBOs using existing and soon-to-be-acquired data.

• Journal of the Korean Society of Costume
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• v.19
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• pp.75-81
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• 1992

The clothing industry is going through very rapid and innovative automation in almost all processes from the initial design of clothing to the dispatch of the products to the retailer. Educational bodies in teaching clothing and textile techniques should offer courses that enable students to grasp the concepts and potential of automation so that they can confidently cope with further development when they enter the real world of the clothing and textile industry. The article suggests how and what to teach about automation and, gives an overview of the current state of automation in the field of clothing and textiles. What to Teach about Automation. $\cdot$What is the automation of the clothing industry\ulcorner $\cdot$The benefits of, and obstacles to automation in the clothing industry. $\cdot$How to automate the manufacturing process. $\cdot$Recent developments in automation machinery. $\cdot$How to Teach about Automation. $\cdot$Install available machinery at the educational institute and train the students. $\cdot$Practical 'in the field' work experience. $\cdot$Visite to textile machinery exhibitions and industrial sites. $\cdot$Using audio-visual methods. $\cdot$Participation in research projects to develop automatic systems.

• Journal of the Korean Society of Costume
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• v.53 no.4
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• pp.177-186
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• 2003

This study is based on the observation of clothes excavated from of YeoHung Min( 1586∼1656)'s grave, which enable to understand of woman's funeral clothes among upper class in mid 17C. Lady Min buried with her husband Jung (Clan of Dong Rae)'s grave where located in KwanAk gu, Seoul was move out another place in 1989. During excavation of the grave, 31 pieces form 5 different type of clothes and total 18 pieces form 8 different from Lady Min (Clan of YeoHung). Remarkable finding from the excavated clothes is the Nuwooli(veil) which is known to be discovered first time in Korea, and a piece of tooth, which is related with funeral custom of those day, and cotton seeds are found from chima(skirt) and Jogori(jacket). Jangot(coat) has been used for the use of over garment assuming the changes of Jogori form during mid of Josun dynasty. It is also remarkable that padded and quilted clothing is still being commonly used until mid-l7C.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.264-271
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• 2007

The flow simulations around ducted-prop of tilt-duct aircraft were conducted in this study. For the investigation of aerodynamic characteristics of various configurations of duct, the axisymmetric flow calculation method combined with actuator disk model for prop were used. The rapid two-dimensional calculation and fast grid generation enable aerodynamic analysis for various duct configurations in a very short time and anticipated to active role in optimal configuration design of duct exposed to various flight modes. For the case of angle of attack or tilt angle, the three dimensional flow calculation is conducted using the three dimensional grid simply generated by just revolving the axisymmetric grid around center axis. Through the three dimensional calculation around duct, the aerodynamic effectiveness of duct as a lifting surface in airplane mode was investigated. The flow calculations around the control vane (wing) installed in the rear section of duct were conducted The aerodynamic data of wing were compared with the data of the ducts to evaluate the aerodynamic effectiveness of ducts.

• Research in Mathematical Education
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• v.13 no.1
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• pp.13-22
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• 2009

School children in Brunei Darussalam, as elsewhere, learn how to apply a lot of algorithms and formulas in mathematics. These include methods of finding the lowest common multiple and highest common multiple of numbers and methods of factorizing quadratics. Investigations and experience have shown that both able and less able students learn to do these mechanically and unimaginatively and in a way that is reliable when answering examination questions. Most of them do not, however, learn these algorithms and methods so as to develop a deeper insight of what they learn and thereby perform even more effectively in examinations. Yet it is possible to teach these and other methods for understanding in ways that are enjoyable and enable students to use them effectively and with flair.

• Asia pacific journal of information systems
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• v.12 no.2
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• pp.99-118
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• 2002

In this paper, we propose a visual relational database query language, VRQL, by modifying and extending the recently proposed $VOQL^*$. Like $VOQL^*$, VRQL, based on ven Diagram and graph, naturally reflects the structure of schemas in queries and has recursive formal semantics. However, VRQL has relationally complete expressiveness, while $VOQL^*$ is only a conjunctive query language. In the logical definition part of VRQL, which is the relational version of $VOQL^*$, most features of $VOQL^*$ are retained, and the semantics of queries are based on the tuple relational calculus. In the procedural definition part of VRQL, by introducing the concept of VRQL view and set operations, the expressiveness of VRQL is increased to the level equivalent to that of the relational algebra. Due to the introduction of VRQL views, existing queries or temporary queries used in the process of creating queries can be represented with views, so that complex queries may be represented more conveniently. Set operations, used with VRQL views, enable us to represent various queries, beyond the expressiveness of conjunctive query languages.

• Asia pacific journal of information systems
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• v.26 no.1
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• pp.66-79
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• 2016

The availability of detailed data on customers' online behaviors and advances in big data analysis techniques enable us to predict consumer behaviors. In the past, researchers have built purchase prediction models by analyzing clickstream data; however, these clickstream-based prediction models have had several limitations. In this study, we propose a new method for purchase prediction that combines information theory with machine learning techniques. Clickstreams from 5,000 panel members and data on their purchases of electronics, fashion, and cosmetics products were analyzed. Clickstreams were summarized using the 'entropy' concept from information theory, while 'random forests' method was applied to build prediction models. The results show that prediction accuracy of this new method ranges from 0.56 to 0.83, which is a significant improvement over values for clickstream-based prediction models presented in the past. The results indicate further that consumers' information search behaviors differ significantly across product categories.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.47-48
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• 2005

This paper describes how an Artificial Neural Network(ANN) can be employed to improve a speed estimation in a vector controlled induction motor drive. The system uses the ANN to estimate changes in the motor resistance, which enable the sensorless speed control method to work more accurately. Flux Observer is used for speed estimation in this system. Obviously the accuracy of the speed control of motor is dependent upon how well the parameters of the induction machine are known. These parameters vary with the operating conditions of the motor; both stator resistance(Rs) and rotor resistance(Rr) change with temperature, while the stator leakage inductance varies with load. This paper proposes a parameter compensation technique using artificial neural network for accurate speed estimation of induction motor and simulation results confirm the validity of the proposed scheme.