• 한국염색가공학회지
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• 제6권2호
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• pp.10-16
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• 1994

Neutral salts have negative or positive effects on the rates of many chemical reactions and also on the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of neutral salt effects on the hydrolysis of ester depends on the charge of esters. Neutral salts accelerate alkaline hydrolysis of esters with negative charge, but decelerate alkaline hydrolysis of esters with positive charge, and have little effect on the alkaline hydrolysis of neutral esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte) (PET), polymeric solid carboxylic polyester with carboxyl end group at the polymer end, is also influenced positively by neutral salts. In the present work, to clarify the mechanism of the neutral salt effect on the alkaline hydrolysis of PET, many salts with different anions like NaF, NACl, NaBr, NaI were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous solutions of many salts in alkali metal hydroxides under various conditions. Some conclusions obtained from the experimental results were summarized as follows. The reaction rate of the alkaline hydrolysis of PET was increased by the addition of neutral salts and In k was increased nearly linearly with the square root of ionic strength of reaction medium. This fact suggested that the ionic strength effect by Debye-Huckel and Bronsted theory was exerted on the reaction. The specific salt effect was also observed. The reaction rate was increased with the decrease in the nucleophilicity of anions of neutral salts, i.e., in the order of $F^-$ <$Cl^-$<$Br^-$<$I^-$. It was thought that the reaction rate was increased in the order of $F^-$ <$Cl^-$<$Br^-$<$I^-$. because the completion of anions with $OH^-$ for carbonyl carbon became weaker with the decrease in the nucleophilicity and with the increase in the size of anions.

• 대한통합의학회지
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• 제4권1호
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• pp.31-39
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• 2016

Purpose : The purpose of this study was to investigate the effects of flexibility and foot pressure on stretching exercise of hamstring muscle with and without pelvis neutral position. Methods : This study was performed on 30 subjects. Thirty subjects were divided into two group; hamstring passive stretching exercise with pelvis neutral position(n=15), hamstring passive stretching exercise without pelvis neutral position(n=15). Both of the group performed the exercise 4 times a week for 6 weeks. The data was analyzed by the paired t-test for comparing before and after changes of factors in each group and the independent t-test for comparing the between groups. Results : The results were as follows. There was statistically significant difference of before and after hamstring flexibility, foot pressure in pelvis neutral position(p<0.05). There was statistically significant difference of before and after hamstring flexibility, foot pressure without pelvis neutral position group(p<0.05). There was no statistically significant difference of between the two group in hamstring flexibility, foot pressure(p>0.05). Conclusion : As a result of this study, though no statistically significant difference of the between groups, we suggest that stretching exercise of hamstring muscle with pelvic neutral may be effective more than stretching exercise of hamstring muscle without pelvic neutral in flexibility, foot pressure.

• 천문학회보
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• 제43권1호
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• pp.51.3-52
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• 2018

Since Voyager 1 passed the Heliopause in 2012, it has provided the observations of the charged particles in the local interstellar medium. However, Voyager 1 only provides the information along with its trajectory. In order to understand the global view of the interstellar plasma flow surrounding the Heliopause, we need another tool. When the interstellar plasmas approach the Heliopause, the ions are deflected around the Heliopause due to the draping of the interstellar magnetic field. The draping of the interstellar magnetic field is strongly connected with the shape of the Heliopause. A fraction of the diverted ions exchanges their charges with the undisturbed primary interstellar neutral atoms, and then the ions become neutral atoms called the secondary interstellar neutral atoms. The newly created neutral atoms carry information on the diverted flow of the interstellar ions, and a fraction of them can travel to the Sun. Therefore, the secondary component of the interstellar neutrals is an excellent diagnostic tool to provide important information to constrain the shape of the Heliopause. The secondary interstellar neutrals are observed by Interstellar Boundary Explorer (IBEX) at Earth's orbit. Since 2009, two energetic neutral atom cameras on IBEX have measured neutral atoms and it has provided sky maps of neutral atoms. In this presentation, we will discuss the directional distribution of the secondary interstellar neutrals at Earth's orbit. In the sky maps, the primary interstellar neutral gas is seen between $200^{\circ}$ and $260^{\circ}$ in ecliptic longitude and the secondary components are seen in the longitude range of $160^{\circ}-200^{\circ}$. We also present a simplified model of the outer heliosheath to help interpret the observations of interstellar neutrals by the IBEX-Lo instruments. We extract information on the large-scale shape of the Heliopause by comparing the neutral flux measured at IBEX along four different look directions with simple models of deflected plasma flow around hypothetical obstacles of different aspect ratios to the flow. Our comparisons between the model results and the observations indicate that the Heliopause is very blunt in the vicinity of the Heliospheric nose, especially compared to a Rankine half-body or cometary shape.

• 대한통합의학회지
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• 제8권2호
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• pp.63-73
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• 2020

Purpose: To investigate breathing-related changes in the balance ability of healthy adults. Methods: The participants were 36 healthy adults in their 20s and 30s. All participants were trained in three breathing (neutral, thoracic, and abdominal) methods one week before measurements. We used AccuSway to measure each participant's balance ability, using each breathing technique, in two postures (bipedal and unipedal). Results: During the bipedal balance task, abdominal breathing produced significant increases in path length and sway velocity. Abdominal breathing resulted in significant changes in sample entropy at the anteroposterior location compared with neutral breathing (p<.05). In the normalized anteroposterior location, there were significant changes in backward movement during thoracic and abdominal breathing compared with those during neutral breathing (p<.05). During the unipedal balance task, path length and sway velocity increased significantly during voluntary breathing compared with those during neutral breathing (p<.05). There was a significant change in backward movement when abdominal breathing-compared with neutral breathing-was used in the normalized anteroposterior location (p<.05). In the normalized left-right location, there was a significant shift to the right during thoracic breathing compared with that during neutral breathing (p<.05). Conclusion: Compared with neutral breathing, altered voluntary breathing patterns affect balance in healthy adults. Our results indicated that that static balance was more affected by abdominal breathing than by neutral breathing. Future studies should examine variables such as the breathing volume, rhythm, and method.

• 생명과학회지
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• 제11권6호
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• pp.595-602
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• 2001

The prelectin histochemical methods had been applied to study mucosubstances properties of esophageal mucous cells in four teleostean species, i, e.. sebastes schlegli, Halichoeres poecilopterus, Bryzoichtys lysimus and Takifugu pardalis. The following methods were used: periodic acid Scheff"s(PAS) reaction, alcian blue(AD) pH 2.5, AB pH 1.0, AB pH 2.5-PAS, aldehyde fuchsin (AF) pH 1.7-AB pH 2.5 and high iron diamine (HID)-AD pH 2.5 stainings. The number size and shape of esophasgeal mucous cells studied depend on the fish species. Esophageal mucous cells of Sebastes schlegli and Halichoeres poecilopterus were mixed with large, medium sized and small mucous cells, but these cells of the species were mixed with medium sized and small mucous cells. The large esophageal with moderate to considerable amount of acid mucin. Most of the large mucous cells in these species contained neutral mucin and strongly sulfomucin, whereas a few mucous cells contained neutral mucin, strongly sulfomucin, and sialomucin. Medium sized and small mucous cells of these species contained considerable to large amount of neutral mucin, and small to considerable amount of acid mucin, Most of the medium sized and small mucous cells contained neutral mucin and sialomucin, but a few mucous cells contained neutral mucin and strongly sulfomucin or neutral combined with strongly sulfomucin and sialomucin. Most of the esophageal mucous cells pf Bryzoichthys lysimus contained small amount of neutral mucin, while on the other hand a feww mucous cells contained small amount of neutral mucin and minimal amount of sialomucin. But the esophageal mucous cells of Takifugu pardalis contained considerable amount of neutral mucin only.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.19-23
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• 2009

This paper focuses on vehicle fuel economy improvement using D-Range neutral control of automatic transmission. The system objected to reducing of fuel consumption during idle. Usually, turbine of conventional auto transmission is mechanically linked to wheel during idling condition. Therefore speed ratio of torque converter is zero for that period. This causes needless power loss by the torque converter slip. To improve this inefficiency automobile makers develops electronically-controlled D-range neutral control system. The D-range neutral control system minimizes slip on the torque converter by shifting gear to a neutral position during vehicle stoped with D-range gear position. However there's insufficient study about the effect of D-range neutral control system on vehicle fuel economy. In this paper, researches are performed on effect of D-range neutral control system on vehicle fuel economy by experiment with two different vehicle. And it is also estimated the effect on vehicle fuel economy using computer simulation. As a result, 1.8% of LA-4 mode fuel economy improvement can be achieved in a vehicle by D-range neutral control system.

• 전기학회논문지
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• 제64권10호
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• pp.1523-1527
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• 2015

Traction power is supplied by three-phase alternating current of 154 kV power grid and electric trains are operated on single phase feeding system. It becomes important to use all the three phases equally and convert them into two-phase electric power (90 degree phase rotation) for traction supply. This is achieved by special transformer from the adjacent traction substation which is separated by a neutral section. Neutral section locations are in front of the substation and between the two substations. The first stage of the Seoul-Busan high-speed railway, design curve radius is larger than 7,000 m and the greatest slope is 25‰. The railway track conditions are evaluated as good enough to install a neutral section at the first stage, but a few factors of coasting operation of the train should be considered at the second stage of Seoul-Busan high-speed railway. The neutral section was located at Kim-cheon substation, which made some neutral section problems produced by the operating train, and the neutral section was moved about 1.5 km to the south toward Dong Dae-gu station due to the track operation condition. Some of the trains which stopped at the existing Kim-cheon Gu-mi station produced another motor block failure after moving the neutral section. In this paper, power quality, system performance and track condition, etc. are suggested to solve the problems.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.37-44
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• 2013

Phase to ground faults are possibly one of the maximum number of faults in power distribution system. During a ground fault the maximum fault current and neutral to ground voltage will appear at the pole nearest to the fault. Distribution lines are consisted of three phase conductors, an overhead ground wire and a multigrounded neutral line. In this paper phase to neutral faults were staged at the specified concrete pole along the distribution line and measured the ground fault current distribution in the ground fault current, three poles nearest to the fault point, overhead ground wire and neutral line. A simplified equivalent circuit model for the distribution system under case study calculated by using MATLAB gives results very close to the ground fault current distribution yielded by field tests.

• 한국의상디자인학회지
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• 제22권3호
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• pp.111-126
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• 2020

The purpose of this study is to understand the gender-neutral phenomenon, to grasp the flow of design, and to seek the future direction of modern fashion design. As for the scope and method of the study, this study was performed based on relevant literature. In terms of visual data, website photos were collected from the collection of S/S in 2016 to F/W in 2020. To assess the properties of the gender-neutral, analysis was implemented on the results after arranging the factors for gender neutrality and the characteristics suggested in the related papers. The fashion-related expert group analyzed the properties of the gender-neutral style from 1,031 pictures, where the gender-neutral style of fashion design collections was applied. As a result of the analysis, the characteristics of the gender-neutral were analyzed and divided into the extended body-positive performance style, the mashup style- respecting the conflicting culture, the street style of coexisting genders, and the fluid style of changing directions. In this study, the attributes were derived as acceptability, playfulness, and sustainability. Accordingly, it is expected that this study will play a fundamental role in the creative fashion design development and unfolding of the fashion industry and fashion designers.

• Journal of Power Electronics
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• 제12권2호
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• pp.344-356
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• 2012

In recent years, multilevel technology has become an effective and practical solution in the field of moderate and high voltage applications. This paper discusses an APF with a three-level NPC inverter. Obviously, the application of such converter to APFs is hindered by the problem of the voltage unbalance of DC capacitors, which leads to system instability. This paper comprehensively analyzes the theoretical limitations of the neutral-point voltage balancing problem for tracking different harmonic currents utilizing current switching functions from the space vector PWM (SVPWM) point of view. The fluctuation of the neutral point caused by the load currents of certain order harmonic frequency is reported and quantified. Furthermore, this paper presents a close-loop digital control algorithm of the DC voltage for this APF. A PI controller regulates the DC voltage in the outer-loop controller. In the current-loop controller, this paper proposes a simple neutral-point voltage control method. The neutral-point voltage imbalance is restrained by selecting small vectors that will move the neutral-point voltage in the direction opposite the direction of the unbalance. The experiment results illustrate that the performance of the proposed approach is satisfactory.