• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.606-613
• /
• 2019

In this paper, a new method for flat sweeping automatic hold of wavelength swept laser has proposed. Through the performance test on the implemented laser, even 5 hours passed, the flat sweeping has held up well, and 56nm flat sweeping range, 1kHz sweeping frequency, and 8.8mW average optical power were obtained. This showes that the proposed can eliminate the necessity of hand-operated polarization control required for previous swept lasers in case of long time operation and also optical spectrum analyzer needed to monitor the sweeping spectrum status.

• Journal of the Korean Society of Visualization
• /
• v.16 no.3
• /
• pp.16-25
• /
• 2018

PIV experiments were carried out to visualize the velocity distribution of the sweeping jet impinging onto a flat plate and kinematic behavior of the jet from the fluidic oscillator. Two parameters such as four different Re cases and four different jet-to-wall distances were examined. Time-resolved two dimensional PIV measurements were performed for both streamwise and normal planes respect to the jet axis. Ensemble averaged and phase averaged velocity fields were obtained for the tested range of parameters. The sweeping frequency of the jet increases linearly with increase of Re. The kinetic energy of the sweeping jet decreases as the distance from the jet to the impinging plate increases. In addition, turbulence flow is generated due to the swinging motion of sweeping jet, and various vortices such as primary and secondary vortex are observed near the impinging wall.

• Journal of Sensor Science and Technology
• /
• v.26 no.5
• /
• pp.324-330
• /
• 2017

In this paper, the automation of sweeping center setting for wavelength swept laser used in SS-OCT has implemented. For 3 regions where the initial FFP-TF pass wavelength can be located, each different DC voltage pattern is applied to FFP-TF. Through its performance test to the laser, fast and exact setting to sweeping central wavelength, flat sweeping with ${\pm}0.5dB$ fluctuation range, and 10 mW average optical power were obtained. This shows that the realized automatic setting process can replace an inconvenient manual setting operation used for current wavelength swept laser. Additionally it cuts costs for optical spectrum analyzer necessary to laser spectrum monitoring.

• Journal of Sensor Science and Technology
• /
• v.26 no.1
• /
• pp.44-49
• /
• 2017

In this paper, the automatic sweep flattening for wavelength swept laser of SS-OCT has implemented. Through its performance test applied to the laser, 50 nm flat sweeping range, ${\pm}0.5dB$ fluctuation range, 22 sec the time required, and 10 mW average optical power were obtained. This shows that the realized automatic process can replace the inconvenient manual operation used for polarization control of current sweeping laser. Additionally it cuts costs for optical spectrum analyzer necessary to sweep monitoring.

• Membrane Journal
• /
• v.8 no.2
• /
• pp.102-108
• /
• 1998

Permeation behavior of the semiconductor rinsing wastewater containing Si particles was examined by ultrafiltration using the polysulfone plate membrane. The permeation flux was gradually decreased with time. It was due to the growth of cake deposited on the membrane surface and the pore plugging by Si particles. Permeation flux of cross flow type was 1.4 times higher than that of the dead end flow type. Nitrogen back flushing which is the removing method of membrane fouling was superior to the water sweeping. With nitrogen back flushing, the decrease of permeation flux due to the fouling was recovered about 85 % to the initial flux in the flat plate membrane system. The rejection rate of Si particles was about 90 % and the size of Si particle in the permeate was about 70 nm.

• The Research Journal of the Costume Culture
• /
• v.3 no.2
• /
• pp.241-260
• /
• 1995

The Maori's traditional clothing materials, basic forms of dress, and the pattern and technique of tatoo were examined in the present study in order to deepen the appreciation of the cultural heritage of the Maori. The research method employed was the analysis of written materials. And a fild-trip was also made for the study. The study was limitted to the traditional culture of body adornment of the Maori including the clothing which is preserved and practicing by them at the present day, and the origin and the process of the historical development of those are not included in the scope of the present study. Followings are the results of the study: (1) By far the most widely used fiber for Maori clothing is abtained from what is commonly called New Zealand Flax. The fiber of kiekie(Freycinetia baueriana) and cabbage trees(Cordyline spp.) may also be used. The strong, long-lasting fiber of toi(cordyline indivisa) is used for a prestige warrior's cloak. Flat strips of ti kauka(Cordyline australi) are also used as thatch on rain cloaks. (2) Regardless of technique used, Maori weaving is always worked horizontally from left to right. Traditionally the work was suspended between two upright turuturu or weaving sticks. As the work progressed a second pair of uprights was used to keep the work off the ground. These uprights were moved forward as required. Because the weaver sat on the ground, the working edge was kept at a height that was comfortable to reach. No weaving tools are used, the wefts(aho) being manipulated by the fingers. The two main Maori weaving techniques are whatu aho patahi(single-pair twining) and whatu aho rua(double-pair twining). (3) The Maori wore two basic garments - a waist met and a cloak. The cloth of commoners were of plain manufacture, while those of people of rank were superior, sometimes being decorated with feather or dyed tags and decorated borders. Children ran more-or-less naked until puberty, being dressed only for special events. Some working dress consisted of nothing more than belts with leaves thrust under them. Chiefs and commoners usually went barefoot, using rough sandals on journeys over rough country (4) The adornment of men and women of rank was an important matter of tribal concern as it was in chiefly persons that prestige of the group was centred, The durable items of Maori persons adornment were either worn or carried. Ornaments of various kinds were draped about the neck or suspended from pierced earlobes. Combs decorated the head. Personal decorations not only enhanced the appearance of men and women, but many had protective magical function. The most evident personal ornament was the hei-tiki made of jade or other material. Maori weapons were treasured by their owners. They served on bottle and were also personal regalia. A man of rank was not fully dressed without a weapon in hand. Also weapons were essential to effective oratory. (5) No man or woman of rank went without some tattoo adornment except in extremely rare instances when a person was too sacred to have any blood shed. The untattooed were marked as beeing commoners of no social standing. This indelible mark of rank was begun, with appropriate rite and ritual, at puberty. And tattoo marked the person as being of a marriageable age. Maori tattoo was unlike most traditional tattoo in that its main line were 'engraved' on the face with deep cuts made by miniature bone chisels. The fill-in areas were not tattooed with cuts but with the multiple pricks of small bone 'combs' that only lightly penetrated the skin surface. The instrument of tattoo consisted of small pots of pumice or wood into which was placed a wetted black pigment made from burnt kauri gum, burnt vegetable caterpillars or other sooty materials. A bird bone chisel or comb set at right angles on a short wooden handle was dipped into the gigment, that a rod or stick was used to tap head of this miniature adze, causing penetration of the skin surface. Black pigment lodged under the skin took on a bluish tinge. A full made facial tattoo consisted of major spirals with smaller spirals on each side of the nose and sweeping curved lines radiating out from between the brows over the forehead and from the nose to the chin. The major patterns were cut deep, while the secondary koru patterns were lightly pricked into the skin.

• Korean journal of applied entomology
• /
• v.49 no.4
• /
• pp.313-324
• /
• 2010

With growing interest in biodiversity in rice paddies, efficient sampling methods for quantitative evaluation of aquatic macroinvertebrates are needed because of their important role in rice paddies' food webs. For this reason, we sought a proper sampling method through comparing data collected by using aquatic net, quadrat, and core in rice paddies located in Chuncheon-si, Kangwon-do, Hongseong-gun, and Chungcheongnam-do. Because the frame of the net was rectangular and had a flat bottom, the area, sampledwith the aquatic net, was calculated by multiplying the net width by the sweeping length, All samples were taken from the space between the rows of rice plants. Twenty four taxa of macro invertebrates were collected in Chuncheon and 28 taxa in Hongseong. In Chuncheon, the number of taxa was similar among three sampling methods (17-18 taxa), but the number of individuals was different (aquatic net, $1,317/m^2$; quadrat, $1,368/m^2$; core, $1,810/m^2$. In Hongseong, the number of taxa sampled by aquatic net was the highest (aquatic net, 25 taxa; quadrat, 21 taxa; core, 16 taxa), but the core was the highest in the number of individuals (aquatic net, $1,586/m^2$; quadrat, $2,595/m^2$; core, $3,704/m^2$. The efficiency of samplers differed among taxa. Most of aquatic insect taxa were more abundant in the aquatic net, while those living on or in the paddy substratum such as Oligochaeta and Chironomidae were collected more in the quadrat sampler. To collect quantitative data for aquatic insects as well as to produce inventory of rare taxa, we suggest, based on samplers used in this study, to take quantitative samples of 6 replications from each of the edge and inner zones of a rice paddy by using an aquatic net, and to take qualitative samples both from sides of levees and the inner zone of rice paddy by using an aquatic net.