• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.9-18
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• 2013

In this paper, we design and implement an intelligent system for finding objects with RFID(Radio Frequency IDentification) tag in which an mobile robot can do. The system we developed is a learning system of artificial neural network that uses RSSI(Received Signal Strength Indicator) value as input and absolute coordination value as target. Although a passive RFID is used for location estimation, we consider an active RFID for expansion of recognition distance. We design the proposed system and construct the environment for indoor location estimation. The designed system is implemented with software and the result related learning is shown at test bed. We show various experiment results with similar environment of real one from earning data generation to real time location estimation. The accuracy of location estimation is verified by simulating the proposed method with allowable error. We prepare local test bed for indoor experiments and build a mobile robot that can find the objects user want.

• Analytical Science and Technology
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• v.29 no.6
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• pp.300-304
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• 2016

The asphalt antistripping agents were synthesized from ethylenediamine (ED) or N,N'-bis(2-hydroxyethyl)ethylenediamine (HEED) with three different fatty acids. The formation of amide bonds were successfully performed and confirmed by FT-IR and $^1H-NMR$ data. The adhesive properties of antistripping agents were compared in terms of contact angle and BBS test. The reaction product of ED with waste animal fat exhibited the most hydrophobic by the contact angle measurement, and the strongest water resistance of 94 % by BBS test. However, the reaction product of ED with waste vegetable oil showed the strongest absolute bond strength of ca. 3610 and 3227 kPa for before and after water conditioning, respectively. For the bond strength in general, the reaction products of ED were superior to HEED reaction products, and the reaction products of animal fat and waste vegetable oil were superior to those of pure soybean oil.

• Computers and Concrete
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• v.31 no.3
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• pp.253-265
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• 2023

In this research, the gene expression programming (GEP) technique was employed to provide a new model for predicting the maximum loading capacity of concrete-encased steel (CES) columns. This model was developed based on 96 CES column specimens available in the literature. The six main parameters used in the model were the compressive strength of concrete (f_c), yield stress of structural steel (f_ys), yield stress of steel rebar (f_yr), and cross-sectional areas of concrete, structural steel, and steel rebar (A_c, A_s and A_r respectively). The performance of the prediction model for the ultimate load-carrying capacity was investigated using different statistical indicators such as root mean square error (RMSE), correlation coefficient (R), mean absolute error (MAE), and relative square error (RSE), the corresponding values of which for the proposed model were 620.28, 0.99, 411.8, and 0.01, respectively. Here, the predictions of the model and those of available codes including ACI ITG, AS 3600, CSA-A23, EN 1994, JGJ 138, and NZS 3101 were compared for further model assessment. The obtained results showed that the proposed model had the highest correlation with the experimental data and the lowest error. In addition, to see if the developed model matched engineering realities and corresponded to the previously developed models, a parametric study and sensitivity analysis were carried out. The sensitivity analysis results indicated that the concrete cross-sectional area (A_c) has the greatest effect on the model, while parameter (f_yr) has a negligible effect.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.218-236
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• 1995

The author studied prognostic indicators of sixty Korean male alcoholics in psychological, social and biological aspects who were divided into abstinent and drinking groups. Thirty patients were assigned to each group. They were controlled in age and sex. Both groups were compared in terms of the demographic characteristics, past drinking history, treatment history, famaily history, ego strength and personality factors differences and distribution of dopamine $D_2$ receptor gene Al allele. Also the author studied relation of clinical course, alcoholic family history and dopamine $D_2$ receptor gene Al allele in both groups. The results were as follows; 1) The abstinent group had higher rate of married state, higher economic status, longer education years and maintained more stable job than the drinking group. But made no differences in occupation and religion. 2) The abstinent group showed higher rate of living with family members than the drinking group, and wives and fellows of the alcoholics anonymous were important factors for maintenance of abstinence. Family loading and parent's characters were not different. 3) The abstinent group had longer maximal length of abstinence but mean amount of alcohol consumption per day were larger than the drinking group. But there were no differences in duration of past drinking, drinking pattern, main drinking time, first drinking age and preference of the kind of alcoholic beverage in the past drinking history. 4) The abstinent group showed stronger treatment motivation, absolute abstinence in treatment goal, more voluntary adimission and maintained longer therapeutic relationship otter discharge than the drinking group. But both groups showed negative attitude toward antabuse therapy. 5) The abstinent group had higher mean score in ego strength scale than the drinking group. 6) In the personality factor questionnaire, the abstinent group showed strong laugh poise and the trait of praxernia, conservatism personality but the drinking group showed tough poise, the trait of weak ego strength(unstableness) and tough mindedness personality. 7) In comparision of dopamine $D_2$ receptor gene A1 allele, the prevalence of A1 allele was seventy percent and the frequency was 0.38 in the abstinent group. The prevalence of A1 allele was sixty percent and the frequency was 0.42 in the drinking group. Both groups were not significantly different in A1 allele prevalence and frequency. 8) In comparision of dopamine $D_2$ receptor gene A1 allele according to alcoholic family history, the prevalence of A1 allele was seventy percent and the frequency was 0.43 in the family history positive group. The prevalence of A1 allele was sixty-one percent and the frequency was 0.38 in the family history negative group. Both groups were not significantly different in A1 allele prevalence and frequency. In comparision of past drinking history according to alcoholic family history, the family history positive group showed earlier first drinking and problem drinking, but the family history negative group hod longer duration of past drinking. The mean amount of alcohol consumption per day, the longest duration of abstinence and Alcoholism Screening Test of Seoul Natoinal Mental Hospital(NAST) results were not significant. In conclusion, the results suggest that successful prognostic indicators of Korean alcoholics are married state, higher economic status, longer education years, stable job, living with family members, longer abstinence during past drinking history, strong treatment motivation, absolute abstinence in treatment goal, voluntary adimission, maintained therapeufic relationship, strong ego strength and the trait of praxernia, conservatism personality. But occupation, religion, alcoholic family history, parent's characters, duration of past drinking, drinking pattern, main drinking time, first drinking age, preference of the kind of alcoholic beverage, attitude to antabuse therapy and distribution of dopamine $D_2$ receptor A1 allele were not significantly related to the prognostic indicators of Korean alcoholics.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.71-78
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• 2012

Recycled aggregates are made from construction wastes, and they have many national and social benefits by saving energy, developing substitute resources, and protecting environment. However, low-quality recycled aggregate with low density and high absorption rate cannot be used for structural concrete aggregate but is used mainly for low added value. Therefore, this study aims to identify the characteristics of the materials of recycled aggregates made after crashing and pulverizing waste concrete. For this, their major physical characteristics of cement content, absolute dry density, absorption rate, etc. were reviewed to make a mix design (draft) for the production of the secondary product and performance evaluation was done on the bending strength, absorption rate, bending strength after freezing and thawing, compressive strength, air-dried gravity, etc. of the test products produced by applying the mix design to compare the results with the quality standards of GR mark. The results of the tests showed that the substitution rate of recycled aggregate increased to 50~90 %, which is of superior quality than the performance standards of GR F 4007. Therefore, it is thought that they can be used for various construction works with certain physical characteristics applicable to the production of secondary concrete products using recycled aggregates.

• Journal of Korean Foot and Ankle Society
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• v.6 no.2
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• pp.181-189
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• 2002

Purpose: We try to evaluate the functional outcomes of the ankle with isokinetic plantaflexion torque for acute achilles tendon rupture cases those treated by primary repair with the Krackow suture technique and early rehabilization. Materials and Method: The authors studied retrospectively, 15 patients of acute achilles tendon rupture treated and followed over six months, from July 1997 to May 2001. There were 12 men and 3 women, and mean age was 39.6year. The repair method of ruptured tendon was single or double Krackow suture technique. One week(5days-2weeks) after operation, early ROM with ankle-foot orthosis was started. We used Arner-Lindholm Scale for the clinical evaluation and analyzed patient's satisfaction and subjective strength deficit. We analyzed the dorsiflexion peak torque and plantarflexion peak torque of the ankle statistically with strength test with Cybex dynamometer. Result: In clinical results, we had 11 excellent cases(73%) and 3 good cases(20%). In patients satisfaction degree, 11 excellent cases(66.6%), 3 good cases(20%) and 2 fair cases(13.4%). And in strength deficit, 3 none deficit (20%), 9 minimal deficit(60%). We evaluated the isokinetic plantar flexion torque in 3months or 6months after operation. After 3 months, isokinetic test showed the mean functional deficits, 32% and 25% at $30^{\circ}$ and $120^{\circ}/sec$, in 7 cases(46.6%) of 15 cases respectively. After 6 months, the mean deficits were in 21%, 24% at 30. and $120^{\circ}/sec$, respectively. At 3 and 6 months' follow up, absolute value of isokinetic test showed increase of 25. 31bs to 421bs and 19.61bs to 271bs at $30^{\circ}$ and $120^{\circ}/sec$, respectively. Conclusion: We had good result for acute achilles tendon rupture treated by Krakow suture technique and early range of motion exercise of the ankle. After 6 months, strength deficit was 21% in all of cases but were able to return pre-injured state. This study shows Krakow suture technique was recommended method for primary repair and early rehabilization of achilles tendon ruptue.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.428-433
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• 2008

The strength capacity properties of concrete are much influenced by water content which has a significant effect on concrete spalling, especially, in high temperature areas. Therefore, the properties of the material's shall be closely examined first by measuring the water content in each material in order to analyze Concrete Fire Characteristics, and a reliable measuring method shall be presented in order to derive the following influence. The method used to measure the water content within concrete is mainly divided into 4 types; ASTM method, Nuclear Magnetic method, Ultrasonic measurement method, Radio Wave method, etc. It is essential to use a reliable measuring method for each experiment. In this experiment, we measured the water content and humidity of concrete by two methods; Relative/Absolute humidity method using VISALA HM44 measuring equipment which is easily measurable compared with other methods regardless of the shape of the experimental model, and a water content measuring experiment using ASTM C 566. If the aggregates are under the condition that their surface is dry but in saturation, there is no change of water content according to concrete curing methods. However if the aggregates are absolutely dry, the water content is significantly changed according to concrete curing methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.175-182
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• 2013

Lately, customers think highly of the emotional satisfaction and as a result, issues on odor are matters of concern. The cases are odor of interior material and air-conditioner of vehicles. In particualar, with respect to the odor of air-conditioner, customers strongly claimed defects with provocative comments : "It smells like something rotten," "It smells like a foot odor," "It stinks like a rag." Generally, it is known that mold of evaporator core in the air-conditioning system decays and this produce VOCs which causes the odor to occur. In this study, partial least squares regression model is applied to predict the strength of the odor and select of important VOCs which affect car air conditioning smell. The PLS method is basically a particular multilinear regression algorithm which can handle correlated inputs and limited data. The number of latent variable is determined by the point which is stabilized mean absolute deviations of VOCs data. Also multiple linear regression is carried out to confirm the validity of PLS method.

• Earthquakes and Structures
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• v.15 no.3
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• pp.319-334
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• 2018

In this paper, an analytical study was carried out to propose an optimum base-isolated system for the design of steel structures equipped with lead rubber bearings (LRB). For this, 5 and 10-storey steel moment resisting frames (MRFs) were designed as Special Moment Frame (SMF). These two-dimensional and three-bay frames equipped with a set of isolation systems within a predefined range that minimizes the response of the base-isolated frames subjected to a series of earthquakes. In the design of LRB, two main parameters, namely, isolation period (T) and the ratio of strength to weight (Q/W) supported by isolators were considered as 2.25, 2.5, 2.75 and 3 s, 0.05, 0.10 and 0.15, respectively. The Force-deformation behavior of the isolators was modelled by the bi-linear behavior which could reflect the nonlinear characteristics of the lead-plug bearings. The base-isolated frames were modelled using a finite element program and those performances were evaluated in the light of the nonlinear time history analyses by six natural accelerograms compatible with seismic hazard levels of 2% probability of exceedance in 50 years. The performance of the isolated frames was assessed in terms of roof displacement, relative displacement, interstorey drift, absolute acceleration, base shear and hysteretic curve.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.85-92
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• 1998

This present paper describes a mathematical model of profile shifted elliptical gears, and this model is based on the concepts of envelope theory and conjugate geometry between the blank and the straight-sided rack cutter. The geometric model of the rack cutter includes working regions generating involute curves and fillets for trocoidal curves, and furthermore the addendum modified coeff. is considered for avoiding undercutting. The addendum modified coeff. is changed linearly along with pitch curves and must be the same absolute value at both major semi-axis and minor semi-axis. If undercutting is at all pronounced, the undercut tooth not only are weakened in strength, but lose a small portion of the involute adjacent to the base circle, then this loss of involute may cause a serious reduction in the length of contact. A very effective method of avoiding undercutting is to use the so-called profile shifted gearing. Non-undercutting condition is examined with the change of eccentricity and addendum modified coeff. in elliptical gears and then the minimum number of tooth is proposed not to gernerate undercutting phenomenon.