• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.4
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• pp.185-223
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• 2022

The classical equation of Jonathan Homer Lane and Robert Emden, a nonlinear second-order ordinary differential equation, models the isothermal spherical clouded gases under the influence of the mutual attractive interaction between the gases' molecules. In this paper, the Adomian decomposition method (ADM) is presented to obtain highly accurate and reliable analytical solutions of a class of generalised Lane-Emden equations with strong nonlinearities. The nonlinear term f(y(x)) of the proposed problem is given by the integer powers of a continuous real-valued function h(y(x)), that is, f(y(x)) = h^m(y(x)), for integer m ≥ 0, real x > 0. In the end, numerical comparisons are presented between the analytical results obtained using the ADM and numerical solutions using the eighth-order nested second derivative two-step Runge-Kutta method (NSDTSRKM) to illustrate the reliability, accuracy, effectiveness and convenience of the proposed methods. The special cases h(y) = sin y(x), cos y(x); h(y) = sinh y(x), cosh y(x) are considered explicitly using both methods. Interestingly, in each of these methods, a unified result is presented for an integer power of any continuous real-valued function - compared with the case by case computations for the nonlinear functions f(y). The results presented in this paper are a generalisation of several published results. Several examples are given to illustrate the proposed methods. Tables of expansion coefficients of the series solutions of some special Lane-Emden type equations are presented. Comparisons of the two results indicate that both methods are reliably and accurately efficient in solving a class of singular strongly nonlinear ordinary differential equations.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.203-208
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• 2023

In this study, we propose a method to improve the precision of contact resistance measurement circuits using constant current method and voltage drop method, and implement a dashboard that monitors the measured data of contact resistance measurement systems through MQTT broker server. The contact resistance measurement system measures the resistance value and transmits the measured value to the MQTT broker server using wireless communications. This developed dashboard uses Node-RED and Node-RED-Dashboard to receive the resistance values of up to four contact resistance measurement systems and show them to user's monitor screen. Users can manage multiple measurement data using a single dashboard and easily interface with other devices through the MQTT broker server. Through the experimental results from real data measurements, the relative standard deviation about precision is improved to average 40.37% and maximum 64.73% respectively.

• Annual Conference on Human and Language Technology
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• 2021.10a
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• pp.66-71
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• 2021

본 연구는 한국어 자질 기반 감성분석(Feature-based Sentiment Analysis: FbSA)을 위한 대규모의 학습데이터 구축에 있어 반자동 언어데이터 증강 기법(SSP: Semi-automatic Symbolic Propagation)에 입각한 자질-감성 주석 데이터셋 FeSAD(Feature-Sentiment-Annotated Dataset)의 개발 과정과 성능 평가를 소개하는 것을 목표로 한다. FeSAD는 언어자원을 활용한 SSP 1단계 주석 이후, 작업자의 주석이 2단계에서 이루어지는 2-STEP 주석 과정을 통해 구축된다. SSP 주석을 위한 언어자원에는 부분 문법 그래프(Local Grammar Graph: LGG) 스키마와 한국어 기계가독형 전자사전 DECO(Dictionnaire Electronique du COréen)가 활용되며, 본 연구에서는 7개의 도메인(코스메틱, IT제품, 패션/의류, 푸드/배달음식, 가구/인테리어, 핀테크앱, KPOP)에 대해, 오피니언 트리플이 주석된 FeSAD 데이터셋을 구축하는 프로세싱을 소개하였다. 코스메틱(COS)과 푸드/배달음식(FOO) 두 도메인에 대해, 언어자원을 활용한 1단계 SSP 주석 성능을 평가한 결과, 각각 F1-score 0.93과 0.90의 성능을 보였으며, 이를 통해 FbSA용 학습데이터 주석을 위한 작업자의 작업이 기존 작업의 10% 이하의 비중으로 감소함으로써, 학습데이터 구축을 위한 프로세싱의 소요시간과 품질이 획기적으로 개선될 수 있음을 확인하였다.

• Lettere Italiane
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• no.37
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• pp.177-209
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• 2012

La Sicilia è una terra, difficile da governare perché è difficile da capire nella natura dei suoi abitanti, contraditoria ed estrema. In questa ricerca si cerca di comprendere la Sicilia, i suoi problemi e i problemii meridionali attraverso maggiormente 『Sicila come metafora』 di Leonardo Sciascia. La Sicilia, come sfondo, ci viene presentata nell' opera sciasciana, in un palcosenico sul quale le virtù del popolo siciliano si pervertono e tutte le loro qualità divengono radice di opposti effetti. Prima di iniziare di capirne va cercato la sua storia: senza considerare la storia non si puo e non si deve riflettere le situazioni attuali nè i problemi. Si può affermare che l'insicurezza è la componente primaria della storia siciliana, la quale regola e condiziona il proprio modo di essere, la visione di vita e dell'ambiente. È interessante studiare la propria storia di Sicilia e si fa cominciare a capirne gradualmente: uno degli elementi della realtà siciliana che ricorre spesso è la mafia, e anche il costume, le donne. Sciascia citta nel 『Il cavaliere e la morte』 che la sicurezza del potere si fonda sull'insicurezza dei cittadini. È talmente assurdo da capire ma questa è la Sicilia. Raggiungendo una definizione della natura dei siciliani con i testi di Sciascia, si potrebbe reppresentare la sicilianità o sicilitudine. Sapendo cos'è e come è la sicilianità capire la Sicilia significa per un siciliano capire se stesso. E poi si puo riflettere meglio dei problemi storici e attuali dell'Italia del Sud, di mafia, dei costumi e delle vittime in quella societa cio'è delle donne. Così il termine sicilianità caratterizza quell'insieme dei caratteri attribuiti all'uomo di Sicilia, tipici cioè del siciliano, definiti anche sicilitudine. E nel scritto Sciascia affermò che la Sicilia è in una situazione molto complicata e disperata. Ora si potrebbe capirlo anche chi sta fuori di quel luogo cosi si potrebbe cercare anche di rimettere in ordine delle cose e di risolverne finalmente.

• Molecules and Cells
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• v.46 no.9
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• pp.538-544
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• 2023

The formation of uniform vitreous ice is a crucial step in the preparation of samples for cryogenic electron microscopy (cryo-EM). Despite the rapid technological progress in EM, controlling the thickness of vitreous ice on sample grids with reproducibility remains a major obstacle to obtaining high-quality data in cryo-EM imaging. The commonly employed classical blotting process faces the problem of excess water that cannot be absorbed by the filter paper, resulting in the formation of thick and heterogeneous ice. In this study, we propose a novel approach that combines the recently developed nanowire self-wicking technique with the classical blotting method to effectively control the thickness and homogeneity of vitrified ice. With simple procedures, we generated a copper oxide spike (COS) grid by inducing COSs on commercially available copper grids, which can effectively remove excess water during the blotting procedure without damaging the holey carbon membrane. The ice thickness could be controlled with good reproducibility compared to non-oxidized grids. Incorporated into other EM techniques, our new modification method is an effective option for obtaining high-quality data during cryo-EM imaging.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.1-9
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• 2003

The purpose of this study was to find out and evaluate discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to it in 45 patients(17 male, 28 female) who were diagnosed as skeletal Class III ma)occlusion and received presurgical orthodontic treatment and orthognathic surgery at Yonsei university dental hospital. Lateral cephalograms were analysed at pretreatment(T1), orthodontic Prediction(T2), immediately before surgery(T3) and designated the landmark as coordinates or X and Y axes. The samples were divided according to ALD, upper and lower incisor inclination(Ul to SN, IMPA), COS, extraction, the position of extracted teeth and the statistical significance was tested to find out the factors contributing to the prediction. The results were as follows: 1. Differences between preorthodontic prediction values and actual postorthodontic values(T2-T3) were statistically significant(p<0.05) in the x coordinates of U6mbc, L1x and in y coordinates of U1i, U1x, U6me, U6mbc, L6mbc 2. The accuracy of prediction is relatively higher in horizontal changes compared to vortical changes. 3. The statistical significance(p<0.05) between prediction and actual values is observed more in the landmarks of the maxilla than the mandible. 4. Differences between prediction and actual values of incisor and first molar were statistically significant(p<0.05) according to extraction vs non-extraction, extraction type, ALD in the maxilla and according to ALD, IMPA in the mandible. Discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to the prediction must be considered in treatment planning of Cl III surgical patients to increase the accuracy of prediction. Furthermore future investigations are needed on the prediction of vortical changes.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.275-281
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• 2009

Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Journal of radiological science and technology
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• v.32 no.2
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• pp.177-182
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• 2009

Purpose : This study presents the optimization of flip angle (FA) to obtain higher contrast to noise ratio (CNR) and lower specific absorption rate (SAR). Materials and Method : T1-weighted images of the cerebrum of brain were obtained from 50$^\circ$ to 130$^\circ$ FA with 10$^\circ$ interval. Signal to noise ratios (SNRs) were calculated for white matter (WM), gray matter (GM), and background noise. The proper FA was analyzed by T-test statistics and Kruskal-wallis analysis using R1 = 1- exp ($\frac{-TR}{T1}$) and Ernst angle cos $\theta$ = exp ($\frac{-TR}{T1}$). Results : The SNR of WM at 130$^\circ$ FA is approximately 1.6 times higher than the SNR of WM at 50$^\circ$. The SNR of GM at 130$^\circ$ FA is approximately 1.9 times higher than the SNR of GM at 50$^\circ$. Although the SNRs of WM and GM showed similar trends with the change of FA values, the slowdown point of decrease after linear fitting were different. While the SNR of WM started decreasing at 120$^\circ$ FA, the SNR of GM started decreasing at less than 110$^\circ$. The highest SNRs of WM and GM were obtained at 130$^\circ$ FA. The highest CNRs, however, were obtained at 80$^\circ$ FA. Conclusion : Although SNR increased with the change of FA values from 50$^\circ$ to 130$^\circ$ at 3T SE T1WI, CNR was higher at 80$^\circ$ FA than at the usually used 90$^\circ$ FA. In addition, the SAR was decreased by using smaller FA. The CNR can be increased by using this optimized FA at 3T MR SE T1WI.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.1-23
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• 1979

The use of barley seeder attached to rotary tiller in the rural area has a significant meaning not only for the solution of labor peak season, but also for the increase of land utilization efficiency. The facts that presently being used barley seeders are all based on the mechanical principles of the reverse rotation, center drive and are all using forward rotating tine, which is used to be easily and heavily worn out when it rotates reversely, raise problem of recommending them to rural area in Korea. Therefore, the main objective of the study was to develop new type of rotary tine attachable to barley seeders. To attain the objective the following approaches were applied. (1) The kinematic analysis of reverse rotating barley seeders. (2) The studies on the soil bin and artificial soil. (3) The comparative experiment on the power requirement of prototype tine. The results obtained from the studies are summarized as follow: 1. The kinematic analysis of barley seeder attached to rotary tiller: The following results were obtained from the kinematic analysis for deriving general formulae of the motion and velocity characterizing the rotary tine of barley seeders presently being used by farmers. a) The position vector (P) of edge point (P) in the rotary tine of reverse rotating, center drive was obtained by the following formula. $$P=(vt+Rcos wt)i+Rsin wt j+ \{ Rcos \theta r sin \alpha cos (wt- \beta +\theta r) +Rsin \theta r sin \alpha sin (wt-\beta + \theta r) \} lk $$ b) The velocity of edge point $(P^')$ of reverse rotating, center drive rotary tine was obtained by the following formula. $$(P^')=(V-wR sin wt)i+(w\cdot Rcoswt)j + \{ -w\cdot Rcos \theta r\cdot sin \alpha \cdot sin (wt-\beta +\theta r) + w\cdot Rsin \theta r\cdot sin \alpha \cdot cos (wt- \beta + \theta r \} k $$ c) In order to reduce the power requirement of rotary tine, the angle between holder and edge point was desired to be reduced. d) In order to reduce the power requirement, the edge point of rotary tine should be moved from the angle at the begining of cutting to center line of machine, and the additional cutting width should be also reduced. 2. The studies on the soil bin and artificial soil: In order to measure the power requirement of various cutting tines under the same physical condition of soil, the indoor experiments Viere conducted by filling soil bin with artificially made soil similar to the common paddy soil and the results were as follows: a) When the rolling frequencies$(x)$ of the artificial soil were increased, the densIty$(Y)$ was also increased as follows: $$y=1.073200 +0.070780x - 0.002263x^2 (g/cm^3)$$ b) The absolute hardness $(Y)$ of soil had following relationship with the rolling frequencies$(x)$ and were increased as the rolling frequencies were increased. $$Y=37.74 - \frac {0.64 + 0.17x-0. 0054x^2} {(3.36-0.17x + 0.0054x^2)^3} (kg/cm^3)$$ c) The density of soil had significant effect on the cohesion and angle of internal friction of soil. For instance, the soil with density of 1.6 to 1.75 had equivalent density of sandy loam soil with 29.5% of natural soil moisture content. d) The coefficient of kinetiic friction of iron plate on artificial soil was 0.31 to 0.41 and was comparable with that of the natural soil. e) When the pulling speed of soil bin was the 2nd forward speed of power tiller, the rpm of driving shaft of rotary was similar to that of power tiller, soil bin apparatus is indicating the good indoor tester. 3. The comparative experiment on the power requirement of prototype tine of reverse rotating rotary: According to the preliminary test of rotary tine developed with various degrees of angle between holder and edge pcint due to the kinematic analysis, comparative test between prototype rotary tine with $30 ^\circ $ and $10 ^\circ$ of it and presently being used rotary tine was carried out 2nd the results were as follows: a) The total cutting torque was low when the angle between holder and edge point was reduced. b) $\theta r$ (angle between holder and edge point) of rotary tine seemed to be one: of the factors maximizing the increase of torque. c) As the angle between holder and edge point ($\theta r$) of rotary tine was $30 ^\circ $ rather than $45 ^\circ $, the angle of rotation during cutting soil was reduced and the total cutting torque was accordingly reduced about 10%, and the reduction efficiency of total cutting torque was low when the angle between holder and edge point ($\theta r$) of rotary tine was $10 ^\circ $, which indicates that the proper angle between holder and edge point of rotary tine should be larger than $10 ^\circ $ and smaller than $30 ^\circ $ . From above results, it could be concluded that the use of the prototype rotary tine which reduced the angle between holder and edge point to $30 ^\circ $, insted of $45 ^\circ $, is disirable not only decreasing the power requirements, but also increasing the durabie hour of it. Also forward researches are needed, WIlich determine the optimum tilted angle of rotary brocket, and rearrangement of the rotary tine on the rotary boss.