• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.925-930
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• 2003

Kinetic studies of the reaction of Z-aryl cyclopropanecarboxylates with X-pyridines in acetonitrile at 55.0 ℃ have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterionic tetrahedral intermediate, $T^{\pm}$. These mechanistic conclusions are drawn base on (i) the large magnitude of ρx and ρz, (ii) the positive sign of ρxz and the larger magnitude of ρxz than normal $S_N2$ processes, (iii) a small positive enthalpy of activation, Δ$H^≠$, and a large negative, Δ$S^≠$, and lastly (iv) adherence to the reactivity-selectivity principle (RSP) in all cases.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.19-21
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• 2004

This paper considers pulse width modulation (PWM) methods which are used in 3-phase brushless DC motor controller. Due to many disadvantages of bipolar PWM method, unipolar PWM method is mostly used in industrial field. In constant speed control application, the unipolar PWM method shows a good performance of speed control. But in the wide range of speed control application, it shows a poor performance especially when deceleration is needed. So we propose hybrid PWM method that utilizes two PWM methods according to the sign of speed controller output. The simulation and experimental result shows that the proposed method improves a speed control performance of the brushless DC motor which is applied to industrial sewing machines.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.444-446
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• 1999

The structure and composition of anodic films, formed on 6063 commercial aluminium alloy at constant current density of $1.5A/^dm2$ with various superimposed cathodic current ratio, in the range 0~33%, in the 11% $H_2SO_4$ with various concentration of $CuSO_4{\cdot}5H_2O$, in the range 0~75 g/l, without cathodic current are generally porous-type and no sign of Cu co-deposition appearance, suggesting that cathodic current is an important factor in the Cu co-deposition. Comparison with the anodic film thickness measurement results obtained from anodic film formed by direct anodic current and anodic film formed by superimposed various portion of cathodic current, the portion of cathodic current of input current increases with decrease of anodic film thickness and increases with increase of concentration of $Cu_2S{\;}and{\;}Cu_2O$ in the anodic film.

• Archives of design research
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• v.16 no.2
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• pp.189-196
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• 2003

The purpose of this study is to examine and understand decoding process of the Advertising - text to users a various aspects of semiotic approaches. Further more, through this study, show the sign- structures of the ad-text. For this purpose this study has chosen about the AD of publication of constant period that explore the variable characteristics, access the audience's meaning - structures. Through this analysis , grasp the point of internal and external linked structures. The results of this study can be summarized as follows; ㆍ The AD were applied using the transformational signifier of sign-system rather than the reflection of life's quality and products itself. Moreover to show itself meaning, the ad should do selection of transformation of thought than information-oriented. ㆍ The AD-text can be produced its productive efforts as well as decoding process of audience through various linked channel. Association, structured linking, audience's decoding, thematic structures are very important points in order to read the AD.

• The Journal of Art Theory & Practice
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• no.7
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• pp.89-123
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• 2009

The Philippines was colonized by Spain for about centuries, from 1521 to 1898, and ruled by America for around four decades, from 1899 to 1946. After recovering from the Second World War, the government started to harness human labor as export itself. In the present time the overseas Filipinos keep the economy afloat with their steady transfer of money to relatives and dependents. Through the art works, the issue which Filipinos were exploited and exported by its government has been reflected as the various allegories. As Filipinos traditionally follow and keep Catholic belief, themes of Christ's sacrifice has allegorically been represented as salvation, struggle, suppression, and emancipation of people. Through the allegory, we can interpret both the intrinsic and superficial texts. Also we can identity certain modes of the visuality of allegory in selected works from Philippine art history that in their complex mediations materialize the people and dignity of their predicament and their prevailing. Philippine art can be divided as three different features: passion, vagrancy, and mass formation. The passion stage was depicted as deep structure of Christian thought and devotional feeling, harsh capitalist system. In the pictures of vagrancy, under the regime of Ferdinand Marcos, the themes of drift, deprivation, and homelessness are reckoned through the images of pictures. The stories represented with allegory have been played an important role to bring local issues up as national ones. Those stages take us to the processes of mass formation or the depiction of the people as a moment in the totality of force. The allegorical sign refers to another sign that precedes it, but with which it will never able to coincide reach back to a previous stage and in this constant attempt at return incorporates a structural distance from its origin. The true people's art is one that radically generates transformative technologies and techniques so that it irrevocably breaks the plane of "art". In the painting, the truth is represented by functioning as foundation of a rhetoric of the image. And at this axis, the passional, the vagrant, and the mass formation tend to come together because they render the form of contingency that must be suffered and hopefully surpassed, a Filipino subjectivity that must be stitched in time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.131-142
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• 1994

This paper analyzes the properties of such algorithm that corresponds to the nonlinear adaptive algorithm with additional update terns, parameterized by the scalar factors ${\alpha}1,\;and\;{\alpha}2$. The analysis of concergence leads to eigenvalues of the transition matrix for the mean filter coefficient vector. Regions in which the algorithm becomes stable are demonstrated. The time constant is derived and the computational complexity of the QFG algorithm is compared with those of the conventional LMS. sign, and LFG algorithm. The properties of convergence in the mean square error is derived and the neccessary condition for the CFG algorithm to be stable is attaned. In the computer simulation a channel equalization is utilized to demonstrate the performance feature of the QFG algorithm. The QFG algorithm has the more computational complexities but the faster convergence speed than LMS and LFG algorithm. Since the QFG algorithm has smoother convergence, it may be useful in case where error bursting is a problem.

• Journal of Photoscience
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• v.9 no.2
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• pp.240-242
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• 2002

In Drosophila melanogaster, it is known that the circadian clock consists of an autoregulatory feedback loop, which includes so-called clock genes, such as per, tim, dClk and cyc and produces periodical expression of per. It is recently suggested, however, that the circadian oscillation without the rhythmical expression of per is involved in the regulation of circadian locomotor rhythms. In the present study, we examined the existence and the property of the possible per-less oscillation using arrhythmic clock mutant flies carrying per$^{01}$, tim$^{01}$, dClk$^{Jrk}$ or cyc$^{01}$. When temperature cycles consisting of 25$^{\circ}$Ｃ and 30$^{\circ}$Ｃ with varying periods (T = 8~32 hr) were given, they showed rhythms synchronizing with the given cycle under constant darkness (DD). per$^{01}$ and tim$^{01}$ flies always showed a peak around 7 hr after the onset of thermophase irrespective of Ts of temperature cycles, while dClk$^{Jrk}$ and cyc$^{01}$ flies did not. In addition, several days were necessary to establish a clear temperature entrainment in per$^{01}$ and tim$^{01}$ flies, when they were transferred from a constant temperature to a temperature cycle under DD. These results suggest that per$^{01}$ and tim$^{01}$ flies have a temperature-entrainable weak oscillatory mechanism. The fact that dClk$^{Jrk}$ and cyc$^{01}$ flies did not show any sign of the endogenous oscillation suggests that the per-less oscillatory mechanism may require CLK and CYC.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.11-21
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• 1999

For microelectronic packaging application, the crystallizable glass powder in CaO-$A1_2O_3-SiO_2-B_2O_3$system was mixed with various amounts of alumina inclusions (\approx 4 $\mu \textrm{m}$), and its sintering behavior, crystallization behavior, and dielectric constant were examined in terms of vol% of alumina and the reaction between the alumina and the glass. Sintering of the CASB glass powder alone at $900^{\circ}C$ resulted in full densification (99.5%). Sintering of alumina-filled composite at $900^{\circ}C$ also resulted in a substantial denslfication higher than 97% of theoretical density, In this case, the maximum volume percent of alumina should be less than 40%. XRD analysis revealed that there was a partial dissolution of alumina into the glass. This alumina dissolution, however, did not show the particle growth and shape accommodation. Therefore, the sintering of both the pure glans and the alumina-filled composite was mainly achieved by the viscous flow and the redistribution of the glass. Alumina dissolution accelerated the crystallization initiation time at $1000^{\circ}C$ and hindered the densification of the glass. Dielectric constants of both the alumina-filled glass and the glass-ceramic composites were increased with increasing alumina content and followed rule of mixture. In case of the glass-ceramic matrix composites showed relatively lower dielectric constant than the glass matrix composite. Furthermore, as alumina content increased, crystallization behavior of the glass was changed due to the reaction between the glass and the alumina. As alumina reacted with the glass matrix, the major crystallized phase was shifted from wollastonite to gehlenite. In this system, alumina dissolution strongly depended on the particle size: When the particle size of alumina was increased to 15 $\mu\textrm{m}$, no sign of dissolution was observed and the major crystallized phase was wollastonite.

• Clinics in Shoulder and Elbow
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• v.7 no.1
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• pp.23-29
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• 2004

It has been reported that rotator cuff tear have good response to arthroscopic or open repair even if the range being so wide. However, the majority of this literature regarding the diagnosis and treatment of tear focused on lesion of the supraspinatus and infraspinatus tendons. But involvement of the subscapularis tendon with rotator cuff tear should be thought to be less common and poorer to open operative repair. Furthermore, some europian author have stated that the rotator cuff tear including the subscapularis tendon are sufficiently distinct in their clinical presentation and prognosis as to merit separate consideration of their diagnosis and treatment. The purpose of this study is to evaluate result of arthroscopic or open repair in patient with rotator cuff tear that include the subscapularis tendon. Of the 128 rotator cuff repairs performed from 1998 through 2003, 12 had a tear that include the subscapularis tendon in combination with the supraspinatus (8 cases) and infraspinatus (4 cases). Mean duration of symptoms before surgical treatment was 6 months (range 3 to 12 months). All 12 patient demonstrated a positive lift off sign. Shoulder function was assessed using the Constant- Murley score, which ranges from 30 to 58. Pain was assessed using a linear visual analogue scale range from 0 to 10. Postoperative Constant score range from 40 to 64 (average 47.8). Pain score improved from 5.5 to 8.5, but there are postoperative pain improvement on nothing in 5 patient. The overall result for 12 patient were satisfy in 2, fair in 5 and dissatisfy in 5: Therefore satisfactory result were noted only in 16 % of this overall group. In conclusion, we have failed to make good result in patient with rotator cuff tear that included the subscapularis tendon. At the result, outcome after surgical repair of this type of rotator tear is comparatively inferior to the result of operative repair of rotator cuff not involved the subscapularis tendon.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.2
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• pp.69-80
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• 2002

In this paper, signed-rank based nonparametric detectors are used for direct sequence code division multiple access pseudo-noise code acquisition systems in frequency-selective Rician fading channels. We first derive the locally optimum rank detector, and then propose the locally suboptimum rank (LSR) and k-th order modified signed-rank (MSRk) detectors using approximate score functions. We compare the serial and hybrid parallel double-dwell schemes using the LSR and MSRk detectors with those using the conventional squared-sum (SS) using the cell averaging constant false alarm rate processor and modified sign detectors. From the simulation results, it is shown that the LSR and MSRk detectors perform better than the SS detector using the cell averaging constant false alarm rate processor.