• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2527-2534
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• 2002

An efficient method is proposed for the design of six-bar function generators with complex design tasks. Especially, the desired functions are defined for the entire motion ranges of the input variables. The design problem is defined as a nonlinear optimization problem. A concept of a weighted structural error is introduced for the definition of the objective function. Also simple branch identifiers are incorporated to eliminate the branch problems commonly encountered in a typical linkage synthesis problem. Two example problems of designing a Watt-II type double dwell mechanism and a Stephenson-III type double beat-up mechanism are demonstrated with numerical results. Constraints such as on the Grashof conditions and on the transmission angles are included for practical solutions.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.178-184
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• 1971

Samples of refined soybean oil were irradiated with lights from a 20-watt incandescent tungsten lamp, a 20-watt fluorescent daylight type lamp, a 20-watt low-pressure mercury vapor germicidal lamp, and direct sunlight for an experimental period of 147 days. Some samples were stored in a dark room throughout the period as a control. The peroxide values of all samples were measured every week. The induction period of the samples was arbitrarily taken as the time required for the samples to reach a peroxide value of 15. The induction period of the control was estimated at 198 days. Those of the samples irradiated with the incandescent light, the fluorescent light, the ultraviolet light, and the sunlight were estimated at 196, 119, 52 and 6 days, respectively. The sunlight showed by far the strongest prooxidant activity whereas the incandescent light showed the weakest but distinct prooxidant activity. The small temperature differences observed among the various samples throughout the experimental period did not seem to affect the oxidation rates of the irradiated samples in any significant way.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.88-98
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• 1998

In many automatization applications, a rigid body is required to go forward and backward repeatedly through a set of given position/orientations precisely while a crank is rotated. Such a motion can be generated by 6 bar mechanism adding a dyad to a 4 bar mechanism. If this is the case for 3 position synthesis of the 4 bar mechanism, the feasible solution area for designing the 4 bar mechanism will be limited over the general solution area. This paper proposes a procedure to synthesize 4 bar mechanism to be used to generate the required motion. It is found that the only input crank of the 4 bar mechanism should be limited to satisfy the condition. And the feasible design area for the circle point/ center point of the input crank is identified so that design of the undesired mechanism could be avoided. The method is tested and the results are shown.

• Journal of the Korean institute of surface engineering
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• v.21 no.2
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• pp.76-82
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• 1988

The bright nickel electroplatings were carried out the Watt bath containg a solobel saccharin as class I brightner and para substituted benzaldehydes as class II one. Extended Huckel MO calculation was done and polarization was measured to examine between $\pi$-electron density and the brightness. The correlation is also investigated between $\pi$-electron density of oxygen atom of aldehyde group and slope of polarization curve. As a result of the analysis of rate equation of nucleation, the surface energy of the deposited particle was obtained from the slope of the plot of $\ell$nI against 1/η2, and also the reat equation of nucleation found to influnced on the leveling on the basis of adsorption theory. We have proposed the general electroplating mechanism that is applied other to all other electroplating but nickel one. The above elucidated mechanism can be extended can be extended to the all electroplating other than bright nickel electroplating.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.123-130
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• 2011

In the precedent study it was presented that the comparison of thermal resistivity using various backfill materials including river sand regarding water content, dry unit weight and particle size distribution. Based on the precedent study, this study focused on developing the optimized backfill material that would improve the power transfer capability and minimize the thermal runaway due to an increase of power transmission capacity of underground power cables. When raw materials, such as river sand, recycled sand, crush rock and stone powder, are used for a backfill material, they has not efficient thermal resistivity around underground power cables. Thus, laboratory tests are performed by mixing Fly-ash, slag and floc with them, and then it is found that the optimized backfill material are required proper water content and maximum density. Through various experimental test, when coarse material, crush rock, is mixed with recycled sand, stone powder, slag or floc for a dense material, the thermal resistivity of it has $50^{\circ}C$-cm/Watt at optimum moisture content, and the increase of thermal resistivity does not happen in dry condition. The result of experiments approach the optimization of the backfill materials for underground power cables.

• Archives of Reconstructive Microsurgery
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• v.2 no.1
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• pp.62-69
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• 1993

Recently, conservative and bloodless operative procedures have been focused, so that endoscopic laser have been used. However application of endoscopic laser surgery for laryngeal lesion is capable for followings: (1)capability of delivery through an operating microscope, (2) vaporization of ultraspot. $CO_2$ laser which has been used, has limitations for voice improvement because of 700 micron beam spot. KTP-532 laser which is capable of delivery through an operating microscope vapore 200 micron ultraspot has developed and applied to microlaryngeal surgery. We have experienced 60 cases who were contracted with hoarseness(53 cases of benign lesions vocal nodule 13, vocal polyp 13, bilateral diffuse polyposis of vocal cords 11, intracordal cyst 8, vocal papilloma 5, laryngocele 1, laryngeal stenosis 2 and 7 cases of malignant lesions : laryngeal carcinoma stage I and II) since 1991. We operated them with KTP-532 Laserscope(3 Watt/0.05 sec., pulsed or continuous. San Jose, Calif, USA). Forty eigh cases(90.6%) of 53 bengin laryngeal lesions and 4 cases(57.1%) of malignant lesions were significantly improved in their voices. There were a few complications and technical problems, but laser surgery alone had a limitation to eradicate the disease.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.487-495
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• 2022

This paper describes the design and development of a high-power transmit receive module(TRM) for mounting on X-band synthetic aperture radar(SAR) of the NEXTSat-2. The TRM generates a high-power pulse signal with a bandwidth of 100 MHz in the target frequency range of X-band and amplifies a low-noise on the received signal. Tx. path of the TRM has output signal level of more than 200 watts (53.01 dB), pulse droop of 0.35 dB, signal strength change of 0.04 dB during transmission signal output, and phase change of 1.7 ˚. Rx. path has noise figure of 3.99 dB and gain of 37.38 ~ 37.46 dB. It was confirmed the TRM satisfies all requirements. The TRM mounted on the NEXTSat-2 flight model(FM) which will be launched using the KSLV-II (Nuri).

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.451-462
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• 1975

The qualities of the grape wines brewed with the varieties of Steuben, Muscat Bailey A, Merlot, Campbell Early and Alden were compared, and studied the mashing methods of the wine with a variety of Muscat Bailey A. and then investigated the aging effects of ultrasonic wave and the baking treatments on the new wines. The results obtained were as follows. 1. Extracts of the new wines brewed with the varieties of Steuben and Alden were 2.55 and 1.88 per cent respectively and the color densities of the wines with Merlot and Alden were 3.5 and 1.05 (optical density) respectively, and the other contents were not significantly different beween varieties. On the Otherhand, the results of sensory test showed that the order of favorite was the wines brewed with Steuben, Muscat Bailey A, Merlot, Campbell Early and Alden. 2. The effect of pasteurization ($55^{\circ}C$, 20 min.) on the inhibition of the growth of undesirable microorganism was appeared almost the same degree as the case of sulfiting (100 ppm), and the pasteurized must was more dense in color but slightly turbid than the case of sulfiting. 3. Glucose syrup was in adequate as a materials for supplemental sugar, and the quality of the new wine further fermented the free-run wine added the alcohol to be a constant alcohol content was almost the same as that of control. 4. Baking at $50^{\circ}C$. for 50 days to t he new wine from 0.45 to 0.65 per cent, and color density was also thicken from 2.8 to 3.17 (O. D). 5. Baking at $40^{\circ}C$. for 50days to the new wine brewed with Muscat Bailey A, increased the ester content of the wine from 0.37 to 0.65 per cent and color density was-also thicken from 3. to 4.2 (O.D). 6. Ultrasonic wave (150 watt, 20Kc) treatment for 10 hours to the new wine brewed with Muscat Bailey A, increased the ester content of the wine from 0.37 to 0.47 per cent.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3943-3955
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• 1975

The purposes of this study are to evaluate the utilization characteristics of electrical power consumption, to grasp the present trends in the use of electrical equipments, to estimate the demand factor and load factor being held, and to evaluate the efficiency of electical uses for the recently electrified farms cultivating paddy rice. For the purposes, 109 sample farms located in eleven villiages electrified in six different years from 1968 to 1973, were chosen at random and investigated on 35 items concerning to electrical uses and wiring systems. The survey was carried out in 1975, in the vinicity of Suweon city. The results are summarized as follows: i) The average annual power consumption on sample farms is considered to be low, being 242.9 Kwh. in 1974, and varied according to the different electrified year and size of cultivated land, respectively. It has significant positive correlation to the area of farm, too. ii) Between the number of year of electrical uses and the power consumption, there is very significant positive correlation, which could be expressed as Y=43.041+16.108 X, where X represents the number of years of electrical uses. The annual increment of power consumption is much greater at the beginning of the electrification than that at the later years, its average being approximately 20 percent. However, it is recommended that any estimation of long-term increments should be carefully investigated. iii) The monthly power consumption varies considerably throughout a year, in which the heaviest farm load occurs in November. Observing the seasonal variation of consumption, the winter-time is the heaviest season while the summer is the lowest. The result implies house lighting is chief contribution to the present electrical consumption on the farms. Comparing the variation of monthly consumption ratios between the sample farms and industries, the electrical uses on the farms are independant of the industrial uses, and further, the agricultural uses are of inverse pattern to the farms from the results that there is negative correlationship between them, iv) The number of electrical equipments used on the farms are occupied chiefly by lighting sources. Next to the lighting sources, household appliances of small quantity and some motors are used. The mean electrical quantity is about 1, 127.4 watt, which corresponds to about 37.6 per cent to the contracted quantity. The composition of quantity is chiefly occupied by the electrical motor of about 1.5 hp., single-phased. The number of the annual utilization hours of each equipment is tabulated in Table IV-5. In contradiction to the high utilization of lighting sources and small household appliances, the motor is poorly used for approximately 22 hours in a year. v) More than 55 per cent of farms want to purchase new electrical equipments such as small household appliances and electrical motors in their number. The impulse of purchasing such items is stimulated by the contacts to the mass media and their knowledge on such equipments. Consequently, the increase of electrical uses could be prompted by such trials as education and demonstration. vi) The demand and load factors on the farms vary considerably according to the greater variation of the power consumption, daily or monthly. The daily demand factor is 22.4 per cent and load factor 18.6 per cent, while the annual demand factor is 1.3 per cent and load factor 70 per cent approximately. Therefore, the low efficiency of construction cost requires re-evaluation of the present contracted quantity of 3 Kw. or increase of electrical uses. vii) The electrical energy on the farms devoted chiefly to lighten the farm residences does not contribute to the farm incomes. Consequently, the cost of electrical consumption presses considerably upon the farm economy. Therefore, there is great need to build up the electrical uses on the farms through the development of new works and techinques to utilize any electrical equipments on the production of farm products. Further more, such the development should be related to increase the actual income of the farm consumers.