• Journal of Periodontal and Implant Science
• /
• v.37 no.3
• /
• pp.613-624
• /
• 2007

Full-mouth disinfection (Fdis) completes the entire scaling and root planing (SRP) in one stage within 24 hours for the prevention of microbial recolonization from untreated sites and ecological niches. The aim of this study is to compare the clinical short-term effects of modified Fdis with those of the conventional SRP in the therapy of moderate and severe chronic periodontitis. Modified Fdis group (5 patients) received the entire SRP within 24 hours using chlorhexidine solution (0.1%) and conventional SRP group (5 patients) received SRP per quadrant at one-week intervals. Clinical parameters were measured at baseline, one month and three months after both therapies. The results of this case report were as follows: 1. There were considerable decreases in sulcus bleeding index and plaque index one month after Fdis. 2. The mean probing depth of single-rooted teeth decreased more in Fdis group than conventional SRP group after therapy and, that of multi-rooted teeth decreased similarly in both groups. 3. The mean probing depth decreased 1.77mm in case of initial probing depth of 4-6mm and it decreased 4.13mm in case of initial probing depth of ${\geq}$ 7mm three months after Felis. 4. There were the smaller increases in gingival recession together with the larger gains in attachment in Fdis group than conventional SRP group after three months. Within the limitations of this study, one could conclude that Fdis has beneficial clinical effects in the treatment of moderate and severe chronic periodontitis and further research would be helpful including more subjects during a longer period to confirm the beneficial long-term effects of Fdis.

• Journal of the Korean Society of Safety
• /
• v.23 no.2
• /
• pp.72-80
• /
• 2008

In a case of an automobile collision, vehicle damage and injury of the driver and the passenger occur. The scale of the collision which is effected by the extent of vehicle damage and the injury of the passenger, depends on the delta-V. Based on the photograph interpretation o the actual case of accidents in the Seoul and the Incheon area, this study measured the depth of crush and calculated the delta-V. Through verifying the correlation of the depth of crush and the change of velocity, relative equation was evaluated and compared with the prior study results to prove that they are almost identical. Thus, the depth of crush can be used as an index of the degree of impact, which can be utilized as the change of velocity to evaluate the level of injury done to the passengers. However, the period of hospitalization and diagnostics claimed by the injured proves to have no correlation with the delta-V and the extent of vehicle damage, this is due to the non-objective way of diagnosis and the anamnesis of the injured. This study established the absolute limit harmlessness and the choosing limit harmlessness, allowing the appraisal for Yes or No of the injury or the harmlessness based on the prior studies. Moreover, utilizing the relative equation formed between the depth of crush and the delta-V, each case of collision was compared and evaluated in comparison to the limit harmlessness to prove that the 90.4% of the so-called 'claiming-to-be-injured' were exaggerating or fabricating.

• Journal of Korea Water Resources Association
• /
• v.47 no.10
• /
• pp.907-919
• /
• 2014

This study presents scour processes and its characteristics around the pile groups using the large eddy simulation (LES) coupled with sediment transport and morphodynamic models. The scour and deposition around pile groups were significantly influenced by the pile interval. In case the non-dimensional pile interval was less than 3.75, the local scours as well as the contraction scour were observed around the pile group. On the other hand, in case the non-dimensional pile interval was more than 3.75, the contraction scour disappeared and only local scours were developed at individual piles. Change in the scour depth at piles located in the upstream was similar with the case of single pile, but the scour depth around piles located in the downstream was lower and showed a significantly different tendency due to the presence of piles in the upstream. The non-dimensional maximum scour depth around the pile group decreased as the pile interval increased.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.25 no.2
• /
• pp.35-41
• /
• 1983

This research is mainly to deal with the effects of submergence treatment on the grain yields of two rice plants, local variety, "Akibare" and Tongil line variety, "Milyang 23". The results obtained are summarized as follows. 1. According to the rice products of each plot the grain yield index was smallest in the plot treated at the early heading stage. The index of the next order became smaller in order of late flowering stage, late reduction division stage, milk ripe stage and dough ripe stage etc. The submerged stage at which the damages were smallest was tillering stage. Under the condition of two thirds or one third submerged depth of plant height, few differences in the grain yield index between Milyang 23 and Akibare was found, but except rooting stage, the damages of milyang 23 by whole submergence during growing period were mostly greater than those of Akibare. Especially the grain yield index of early heading stage at which the damages by whole submergence was most serious showed 45 percentage for one day submergence, 31 percentage for 3 days and 0.7 percentage for 7 days in Akibare plots, and 26.7% percentage for one day submergence, 7.9 percentage for 3 days and none for 7 days in Milyang 23 plots. 2. All the factors such as submerged stage, submerged depth and submerged period in this experimental test were highly recognized significance. The factors of the submerged depth and duration influenced on greater damages than the others. According to the difference in grain yield between plots, the larger the submerged depth and duration were, the larger the significant difference appeared. And between the treated levels at other submerged stages except both early tillering stage and most active tillering stage, the significance in the differences in grain yield was recognized, while only the submergence at early heading stage showed the most serious damages. 3. The decreased rate of grain yield for one day submergence at early heading stage indicated that in case of whole submergence of plant height it was 73 percentage in Milyang 23 plot and 55 percentage in Akibare plot, and in the event of two thirds and one third submergences of it, 20 percentage and 10 percentage in both Mulyang 23 and Akibare plots respectively. Therefore, the current criteria for planning project that restricted allowable submergence duration of more than 30cm submerged depth to 24 hours, should be amended not to exceed the submerged depth of 60cm when the duration of more than allowable submerged depth of 30cm will be limited to 24 hours, or within the limits of 12 hour submerged duration for locai variety and of less than 12 hour duration for Tong-illine variety as long as possible in case that submerged depth will be allowed to more than 60cm depth.ore than 60cm depth.

• Current Research on Agriculture and Life Sciences
• /
• v.18
• /
• pp.33-42
• /
• 2000

A field case study was performed to investigate the effect of shallow ponding in paddy field on irrigation water requirement of direct seeded rice. In addition, an economic analysis was made to see the effect of no-till direct seeded rice on cost reduction. A field study was performed at a 2.1ha paddy field in Kimjae city, Chonbuk province from 1991 to 1999. Various direct seeding methods such as dryland seeding, wetland seeding, and no-till wetland seeding were introduced. Then, cost reductions due to the direct seeding and no-till were calculated. In addition, to investigate the effect of shallow ponding on irrigation water requirement, field measurements such as irrigation water volume, drainage water volume, rainfall depth, and ponding depth, were made at a 40a plot within the same area in 1988 and 1990. The results of the shallow ponding study showed that the irrigation water depth, rainfall, and the drainage depth were 379mm, 458mm, and 448mm in 1988 growing season, and 274mm, 819mm, and 736mm in 1990, respectively. The shallow ponding irrigation method saved irrigation water by about 20% with higher yield compared with the traditional method. The economic analysis showed that won \640,000 per ha can be saved by direct seeding due to no nursery cost, and \1,220,000 per ha due to no-till and no nursery cost. The yields ranged 540 to 640 kg per 10a during the study period with an average of 590kg per 10a. If these cropping techniques with no-till direct seeding and shallow ponding depth for rice cropping prove to be advantageous with further study, they can be adopted for the most of the paddy fields in Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.20 no.3
• /
• pp.255-267
• /
• 2008

Using the commercial CFD code FLOW-$3D^{(R)}$ which has an implicit General Moving Object (GMO) method, the ship-induced wave has been simulated. In the implicit GMO method of the FLOW-$3D^{(R)}$, a rigid body's motion which is either user-prescribed (prescribed motion) or dynamically coupled to fluid flow (coupled motion) can be computed with six degrees of freedom (DOF). The simulated horizontal wave patterns are agree with the wave patterns represented by depth Froude number. The model has been well-simulated to generate the depth-dependent wave transformation in comparison of uniform depth case to complicated depth case. Additionally, it shows that ship-induced waves have been reasonably generated by two ships passing each other and by a ship moving in a curve. Therefore, it is suggested that the FLOW-$3D^{(R)}$ model calibrated with observed data should provide more accurate prediction for the ship-induced wave in a certain fairway or harbor.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.9 s.174
• /
• pp.115-122
• /
• 2005

Errors resulting from magnification variations of a optical system are largely generated in three-dimensional shape measurements based on depth-from-focus. In the case of measuring the surface morphology of tiny objects based on DFF, images are acquired with a very small interval so that magnification changes can be minimized. However, the magnification variations are actually existed in the acquired images and so focus measures are wrongly or ambiguously extracted. In this paper, a methodology with linear magnification calibrations, based on DFF, is proposed to make more accurate measurement in surface morphology with high depth discontinuity, compared with previous ones. Several experiments show that the proposed method outperforms existing ones without magnification calibrations.

• Textile Coloration and Finishing
• /
• v.15 no.4
• /
• pp.1-7
• /
• 2003

We investigated the effect of color depth on polyester fabrics by plasma treatment. In this study, although it have many paper about effects of plasma treatment, we observed interfacial electrokinetic potential of polyester fabrics by plasma treatment and also we investigated relationship between deep coloring agent and plasma treatment to get the effect of color depth on polyester fabrics. The results obtained are as follows, 1. Plasma treatment did not enhanced the effect of color depth of polyester fabrics by plasma treatment independently. 2. In the case of using the deep coloring agent with plasma treatment on polyester fabrics, lightness was more decreased than using the deep coloring agent itself. 3. Plasma treatment could not affect surface shape and tensile strength of treated polyester fabrics.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.6 no.1
• /
• pp.77-83
• /
• 2000

En coastal area, many submarine facilities such as pipes and cables are installed on/under the sea bed. Also, there are heavy traffic due to numerous vessels which call in ports or navigate passages in adjacent water. Therefore, the frequency of dropping anchors will be increased to avoid various dangerous situations. When an anchor is dropped from vessel on the sea bed, the anchor strikes on the sea bed, and then, the anchor penetrates to certain depth into the sea bed. In this case, sometimes submarine facilities on/under the sea bed may be damaged by the strike or the maximum penetrating depth of anchor. In this paper, some approximate equations on the strike and the penetrating depth of anchors have been derived on the basis of actual data, and the results are expected to use as basic design data of related facilities.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.3
• /
• pp.21-27
• /
• 1997

This paper aims to clarify the effects of grinding conditions in form grinding of Sr-ferrite with the electro-plated diamond wheel. The main conclusions obtained were as follows. (1) The flexural strength and surface roughness of ferrite became the best at the peripheral wheel speed of 1700 m/min. (2) In the case of the depth of cut larger than 0.4mm, crack layers is induced in the ground surface, and the fracture type of chips exhibits slight ductile mode in the depth of cut smaller than 0.2mm. (3) Whe the depth of cut exceeds 0.6mm, the wheel life becomes extremely severe due to the large chipping and brack- age in the diamond grains. However, at the depth of cut .leq. 0.05mm, the diamond grain shows abrasive wear. (4) The decrease of flexural strength and the increase of surface roughness is in proportion to the increase of the feed rate. (5) Most effective nozzle setting angles with various delivery conditions of the grinding fluid, such as nozzle position .PHI. , flow rate Q, etc., were made clear.