• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.2
• /
• pp.139-146
• /
• 2012

A multi-tasking machine tool for large scale marine engine crankshafts has been developed together with design technologies for its special devices. Since work pieces, that is, crankshafts to be machined are big and heavy; weight of over 100 tons, length of 10 m long, and diameter of over 3.5 m, several special purpose core devices are necessarily developed such as PTD (Pin Turning Device) for machining eccentric pin parts, face place and steady rest for chucking and resting heavy work pieces. PTD is a unique special purpose device of open-and-close ring typed structure equipped with revolving ring spindle for machining eccentric pins apart from journal. In order to achieve high rigidity of the machine tool, structural design optimization using TMSA (Taguch Method based Sequential Algorithm) has been completed with FEM structural analysis, and a hydrostatic bearing system for the PTD has been developed with theoretical hydrostatic analysis.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.55-57
• /
• 2007

$CO_2$ laser sees that is most suitable to get this effect through minimum formation damage and advantage that is root enemy of effect that happen in minimum cellular tissue depth of 0.1mm is stable living body organization or internal organs institution. Formation damage by ten can be related in formation's kind or energy density, length of evaporation time. If shorten evaporation time, surroundings cellular thermal damage 200 - because happen within 400ums laser beam in rain focus sacred ground surroundings cellular, tissue without vitiation me by evaporation Poe of very small floor as is clean steam can. Application is possible to vulva cuticle cousins by a paternal aunt quantity, uterine cancer, cuticle tumor by laser system that $CO_2$ laser gets into standard in obstetrics and gynecology application. Because effect that super pulse output is ten enemies of laser if uniformity one pulse durations are short almost is decreased, most of all pulse module special quality of pulse style $CO_2$ laser for obstetrics and gynecology mode stabilization by weight very, in this research to get into short pulse duration and higher frequency density, do switching by high frequency in DC-DC Converter output DC's ripple high frequency to be changed, high frequency done current ripple amount of condenser for output filter greatly reduce can. Ripple of output approximately to Zero realization applying possible inductor realization through a special quality experiment do.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.8 no.1
• /
• pp.29-37
• /
• 2004

The overstrength factor and the ductility factor are the two important factors that determine response modification factors used in current seismic codes, In this paper the overstrength and ductility factors of special concentric braced frames are determined by performing pushover analysis of model structures with various stories and span lengths. and by using those factors the response modification factors are obtained. According to the analysis results. the overstrength and the ductility factors are larger than the values proposed by the codes in low-rise structures. and the opposite is true in medium to high-rise structures, It is also found that the factors increase as the height of structures decreases and the span length increases.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.4 no.4
• /
• pp.22-27
• /
• 1967

The general mutual impedance expression for two staggered parallel, centerfed, linear antennas of unequal length and confirmed that the general expression being applied to a special case, reduced to the equation presented by other. Furthermore, calculation is done for a special cast, and it is confirmed that the general mutual impedance expression is applicable to the calculation of radiative curreut distribution on antenna system given above.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.857-862
• /
• 2004

This paper analyzes properties of the recently developed nonlinear optimization method, Dynamic Encoding Algorithm for Searches (DEAS) [1]. DEAS locates local minima with binary strings (or binary matrices for multi-dimensional problems) by iterating the two operators; bisectional search (BSS) and unidirectional search (UDS). BSS increases binary strings by one digit (i.e., zero or one), while UDS performs increment or decrement to binary strings with no change of string length. Owing to these search routines, DEAS retains the optimization capability that combines the special features of several conventional optimization methods. In this paper, a special feature of BSS and UDS in DEAS is analyzed. In addition, a effective global search strategy is established by using information of DEAS. Effectiveness of the proposed global search strategy is validated through the well-known benchmark functions.

• Kyungpook Mathematical Journal
• /
• v.60 no.2
• /
• pp.375-385
• /
• 2020

Minkowski spaces have long been investigated with respect to certain properties and substructues such as hyperbolic curves, hyperbolic angles and hyperbolic arc length. In 2009, based on these properties, Chung et al. [3] defined the basic concepts of special relativity, and thus; they interpreted the geometry of the Minkowski spaces. Then, in 2017, E. Nesovic [6] showed the geometric meaning of pseudo angles by interpreting the angle among the unit timelike, spacelike and null vectors on the Minkowski plane. In this study, we show that hyperbolic angle depends on time, t. Moreover, using this fact, we investigate the angles between the unit timelike and spacelike vectors.

• Journal of the Korean Mathematical Society
• /
• v.37 no.6
• /
• pp.1043-1057
• /
• 2000

This paper is devoted to the investigation of mixed Fourier-Bessel transformation (※Equations, See Full-text) We apply the method of [6] which provides the estimate for weighted L(sub)$\infty$-norm of the spherical mean of │f│$^2$ via its weighted L$_1$-norm (generally it is wrong without the requirement of the non-negativity of f). We prove that in the case of Fourier-Bessel transformatin the mentioned method provides (in dependence on the relation between the dimension of the space of non-special variables n and the length of multiindex ν) similar estimates for weighted spherical means of │f│$^2$, the allowed powers of weights are also defined by multiindex ν. Further those estimates are applied to partial differential equations with singular Bessel operators with respect to y$_1$, …, y(sub)m and we obtain the corresponding estimates for solutions of the mentioned equations.

• Korean Journal of Child Studies
• /
• v.28 no.4
• /
• pp.209-227
• /
• 2007

A structured questionnaire was distributed to families using some of the ten specialized caring facilities throughout Gyeongbuk Province. Of the 294 responses, 242 were usable. Results showed that (1) facilities were most used by families of children with autism (31.3%) and by families with severely handicapped children (96.3%). (2) Suggestions for improving facilities, included physical-, performance-, and language-therapies (60%) and teachers with expertise in special education (47.8%).(3) More than half of the respondents were satisfied with the degree of care. (4) Satisfaction with degree of caring services varied with academic background of mothers, mothers' job status, degree of child's disability, length of usage, average expenditure for hospital visits, and burden to the family.

• Journal of the Korean Society of Costume
• /
• v.55 no.5 s.95
• /
• pp.108-119
• /
• 2005

The objective of the study is was investigate the condition of the battle dress uniform worn by male members of the Korean Police Special Weapons Attack Team(KP-SWAT), identify problems, and provide basic raw materials for developing improved design of BDU. For this purpose, the researcher conducted a questionnaire survey on 92 male members of SWAT (Special Weapon Attack Team) units in Seoul using a questionnaire developed through observation and interview. Also, the body sizes of male SWAT members were measured. According to the results of body size measurements, male SWAT members generally require uniforms with a target bust girth, armhole, biceps circumference, thigh and calf circumference, longer jacket length, sleeve length, and trouser length to the knee. According to the results of the questionnaire survey, they reported dissatisfaction with the fit. In addition, they said that the Pockets are positioned too low for convenient use. Many subjects reported that their trousers were too short because of the rubber rings at the bottom of the legs. In addition, many subjects requested the alteration of the inconveniences caused by the designs finished with velcro on the bottom collar of the upper uniform, the marks and ensigns of the upper uniform, the bottom of the upper and lower uniform, and several pockets. Furthermore, there were many complaints concerning how they had to wear their uniform. The most frequently worn out and the body parts most often injured in field training and operations, they were reported, on the upper uniform, as the elbow, collar, neck, armpit, shoulder, and sleeve hem in that order, and on the lower uniform, the knee, interior calf, waist (belt rings), buttocks (rear pockets), and the bottom of the trousers (ankle) in that order As for questions concerning priorities in the improvements of the operational uniform and preferred design, the subjects recommended improvement in safety (protectiveness), workability (motional flexibility), design (shape), fit (size), comfort, ease in terms of putting on and taking off, etc., and the majority preferred two-piece designs ($67.4\%$), followed by one-piece ($30.4\%$), or both ($2.2\%$).

• Korean Journal of Cognitive Science
• /
• v.21 no.4
• /
• pp.481-503
• /
• 2010

In the present study, we examined global and local characteristics of eye movements while 17 Korean third-graders read a Korean story and an expository text. In story reading, children fixated for about 213ms at an eojeol(word cluster), made a forward saccade of about 3.6 characters to the next eojeol, and regressed backward at 30.8% on average. In expository text reading, children fixated for about 214ms at an eojeol, made a forward saccade of about 3.3 characters to the next eojeol, and regressed backward at 31% on average. In addition, the effects of eojeol length, word frequency and landing position were examined. The gaze duration in the long ejoels was longer than in the short eojeols. In a further analysis where the repeatedly used eojeols were excluded, the eojeol length effect appeared in the low-frequency words, but seemed to disappear in the high-frequency words. In terms of landing position, the eyes seemed to land near the center of an eojeol more frequently than on the boundaries. When the eyes landed at the boundary of an eojeol, the eyes tended to fixate the eojeol again.