• 한국산업융합학회 논문집
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• 제25권2_1호
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• pp.149-159
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• 2022

Biomass is material that is comprehensive of carbonaceous materials from plants, crops, animals, and algae. It has been used as one of heating fuel since the beginning the emergence of human beings. Since biomass is regarded as carbon-neutral energy source, it has recently been attracting attention as an energy source that can replace fossil fuels. The most widely applied field is distributed power generation, and a method of generating electric power by driving an internal combustion engine with syngas produced by gasifier is chosen. While the composition of the syngas produced in gasifiers changes depending on the air flowing into the reactor, commercialized gasifiers so far do not control the air flowing into the reactor. When the inner pressure in reactor increases, the air sucked into the reactor is reduced. That change of amount of air makes the composition of syngas varied. Those variations of composition of syngas cause the incomplete combustion hence the power output of engine drops, which is a critical weakness of the gasification technology. In this paper, to produce the uniformly composed syngas, PID control is applied. The result was shown when the amount of air into the reactor is supplied with the constant amount using PID control, the standard deviation of caloric values of syngas is around 2[%] of its average value. Meanwhile the gasifier without PID control has the standard deviation of caloric values is around 7[%]. Therefore, Adopting PID control to supply constant air to the gasifier is highly desirable.

• 대한치과보철학회지
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• 제30권1호
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• pp.15-24
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• 1992

The purpose of this study was to analyze the mandibular asymmetry of the patients with the temporomandibular dysfunction. In this study, 20 dental students aged between 22 and 27 years, Chosun University, who did not possess any restoration and symptoms like the temporomandybular joint click, pain, and opening limitation of the mandible were selected as the normal group. And 80 patients who were analyzed into the patients with the temporomadibular dysfunction(TMD) were divided into group I as the internal derangement and group II as external derangement. Both the normal group and the TMD Group were faked submento-vertex cephalogram by routine methods after that the unilateral mandibular length(L) and the amount of mandibular asymmetry and deviation were measured and analyzed. The results were as follows : 1, Unilateral mandibular length(L) of the normal group and the TMD group were $112.7{\pm}10.20mm\;and\;102.65{\pm}8.10mm$ respectively (P<0.01). 2. The amount of mandibula asymmetry of the normal group and the TMD group were $5.95{\pm}4.63mm\;and\;5.68{\pm}4.35mm$ respectively (P<0.5). 3. The amount of mandibular deviation of the normal group and the TMD group were $6.00{\pm}4.07\;and\;4.67{\pm}3.40mm$ respectively (P<0.3). 4. In the TMD group, unilateral mandibular length(L) in the affected site and the non-affected site were $102.73{\pm}8.68mm\;and\;102.53{\pm}7.68mm$ respectively (P<0.5).

• 한국실내디자인학회논문집
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• 제20권5호
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• pp.143-151
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• 2011

Since it is important to understand data acquiring characteristics through relationship between spatial types and spatial elements and apply it to spatial plans for smooth communication between designer and user of space, the conclusions gained from analysis of data acquiring characteristics of spatial elements through image evaluation by types of interior space can be summarized as in the followings: First, for the amount of acquired data by types of interior space, it shows that the acquired amount of data is to change by types and data acquiring method (phrase and image) even though the spatial elements are same. Second, for the data acquiring process of spatial types by gender, it shows that there is a big difference in acquiring of data according to the evaluation method by phrase and image. Third, for the amount of acquired data of spatial types by gender, it shows that there is a difference between male and female, which is by "classic ${\rightarrow}$ modern ${\rightarrow}$ natural" in case of male and "classic ${\rightarrow}$ natural ${\rightarrow}$ modern" in case of female. regarding both of phrase and image. Fourth, for the evaluation by gender, it shows that there is a deviation in the value of difference according to the elements by which data acquiring characteristics evaluate space. It is considered that this deviation characteristic is in need of reflection in the process of spatial evaluation. This study analyzed data acquiring characteristics of space user's spatial elements through image evaluation by types of space to understand how data acquiring would be changed of spatial elements according to type and gender. Through this study, it expects to make clear that, when a designer is planning a certain space, if the space can be a space for the user by understanding of which elements should be exposed to users by types to acquire more data.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.69-74
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• 2006

Recently, spillways are need to control stable water level for supporting main dams because of floods by unusual change of weather such as Typhoon Rusa. This study has been focused on the amount of leakage through the rock mass distributed fractures and joints under the opened emergency spillway. It is very important to evaluate the amount of leakage as these affect stability of spillway by interaction between effective stress and pore pressure. The commercial program MAFIC has been used for analyzing groundwater flow in fractured rock mass. The results showed that the values of range, average and deviation of leakage were $2.85\sim\;3.79\times10^{-1}$, $3.32\times10^{-1}$ and $1.70\times10^{-2}\;m^3/day/m^2$ respectively. Secondary, we have estimated the effect of grouting after the transmissivity$(T_f)$ of joint 1 as main pathway of leakage known from above results was changed from $1.78\times10^{-7}$ to $1.59\times10^{-9}\;m^2/s$. The results showed that the values of range, average and deviation of leakage were $7.80\times10^{-4}\sim1.53\times10^{-3}$, $1.18\times10^{-3}$ and $1.32\times10^{-4}\;m^3/day/m^2$ respectively. As the result, the amount of leakage after grouting has been decreased by a ratio of 1 to 277.

• 한국전기전자재료학회논문지
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• 제18권9호
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• pp.815-820
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• 2005

ZnO varistor ceramics were fabricated with variation of addition of glass-frit amount and the sintering temperature was $1100^{\circ}C$. The average grain sizes were showed increased from $8.6{\mu}m\;to\;10{\mu}m$, and varistor voltages were decreased from 506V to 460V by added amount of glass-frit. Nonlinear coefficient $\alpha$, of all were with increasing the amount of glass-frit more than 70, in case of added on $0.03wt\%$ glass-frit was 83. And leakage current were less than $1{\mu}A$ with applied at $82\%$ of varistor voltage. The clamping voltage ratio of the specimens added $0.03wt\%$ glass-frit was 1.41 at applied 25A $[8/20\;{\mu}s]$. In the specimen added $0.03wt\%$ glass-frit, endurance of surge current and deviation of varistor voltage were $6200A/cm^2,\;\Delta-1.67\%$, respectively and clamping voltage ratio was 2.33. In the Specimen added $0.03wt\%$ glass-frit were superior to any other compositions on High Temperature Load Test(HTLT) for 1000 hr at $85^{\circ}C$, and deviation of the varistor voltage were $\Delta-1.29\%$.

• 한국환경과학회지
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• 제9권4호
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• pp.295-302
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• 2000

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone, nitrogen dioxide and meteorological data for 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was the highest at Dongsamdong in Spring(35.4ppb), at Kwangbokdong in Fall(25.1ppb) and the lowest Dongsamdong(22.2ppb) and Kwangbokdong(16.0ppb) in Winter. Relative standard deviation indicating clearness of observation site was 0.42 at Dongsamdong and 0.49 at Kwangbokdong that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong and Kwangbokdong showed maximum at 1500~1600LST and minimum 0700~0800LST that typical pattern of ozone concentration. In ozone episode period(Sept. 10~15, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface. During the episode days peak ozone concentrations are much higher than the normal values, wind speeds are always lower, and solar radiation is high with the exception of the September episode.

• 환경영향평가
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• 제8권2호
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• pp.21-29
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• 1999

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone and meteorological data of 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was highest in Spring(35.4ppb) and lowest in Winter(22.2ppb). Relative standard deviation indicating clearness of observation site was 0.42 that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong showed maximum at 15~16LST and minimum 07~08LST that typical pattern of ozone concentration. In ozone episode period(May 18~23, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface.

• 한국의류산업학회지
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• 제21권6호
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• pp.821-829
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• 2019

This study investigated the location of grading lines and grading amount for a jacket item by the target age groups (20-30, 30-40, and 40-50) for 17 women's wear brands. This study then utilized 7th SizeKorea data to analyze the increase rate of body size and to suggest the grading deviation distribution ratio of the jackets using regression analysis. The increase in neck girth of the jackets targeting aged 30-40s did not reflect the human body change rate. The shoulder length increased by 4.6%-8.1% with the bust girth increase; however, the brands produced longer shoulder length reflecting 20-35% of the bust girth increase. The armhole girth was 54.9% - 59.7% of bust circumstance increase rate. However, the 20-30 target age group brands distributed 80% of bust girth to armhole girth and the 30-40 and the 40-50 target age group brands distributed 50% of the bust girth to armhole. In particular, the 20-30 target age group brands were found to produce a large margin around the armhole. When it came to length items, the brands targeting 20-30s and the 40-50s reflected deviation distribution rate of length from underarm to waist and length from waist to hip in comparison with the overall jacket length deviation. The 30-40 target age group brands, 8 out of 20 brands distributed the jacket length deviation in the length from the back of neck to the underarm; consequently, only 22% percent should be distributed in this part.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.61-65
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• 2009

Purpose: Most nasal bone fractures involve the septum; either or both of the ethmoidal perpendicular plate(EPP) and quadrangular cartilage(QC). Unlocked tension from the underlying quadrangular cartilage and poorly reducted bony septum are obstacles to the successful reduction of nasal bone. So we compared the preliminary outcome of septoplasty as a primary treatment with the untreated septum in nasal bone fractures. Methods: We performed a retrospective study of 215 patients underwent reduction of nasal fracture between January 2002 and February 2008. We graded patients into four groups according to the amount of deviation and direction of force by CT. Our indication for septoplasty and combined procedures was the deviation of EPP or QC over 50% from the midline. We interviewed part of the patients by telephone regarding the subjective esthetic and functional outcomes. Results: Forty five of 215 patients (21 percent) underwent septoplasty and combined procedures (cartilage graft, etc) after the informed consent. Patients who underwent septoplasty significantly satisfied with the outcome of esthetic appearance and nasal patency compared with patients who underwent simple closed reduction despite of having septal deviation over 50 percent from the midline. (p < 0.05) Conclusion: Septal surgery and esthetic consideration shoud be made even in simple nasal reductions. And if CT scans reveal severe deviation of septum, septoplasty should be considered as a primary treatment.

• 대한금속재료학회지
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• 제46권10호
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• pp.609-616
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• 2008

Conventional bake-hardenable(BH) steels should be annealed at higher temperatures because of the addition of Ti or/and Nb which forms carbides and raises recrystallization start temperature. In this study, the development of new BH steels without Ti or Nb addition has been reviewed. The new BH steels have nearly same mechanical properties as the conventional BH steels even though it is annealed at lower temperature. The steels also show smaller deviation of the mechanical properties than that of the conventional BH steels because of the conarol of solute carbon content during steel making processes. The deviation of mechanical properties in conventional BH steels is directly dependent on the deviation of solute carbon which is greatly influenced by the amount of the carbide formers in conventional BH steels. Less alloy addition in the newly developed BH steels gives economical benefits. By taking the advantage of sulfur and/or nitrogen which scarenge in Interstitial-Free or conventional BH steels, fine manganese sulfides or nano size copper sulfides were designed to precipitate, and result in refined ferrite grains. Aluminum nitrides used as a precipitation hardening element in the developed steels were also and resull in fine and well dispersed. As a result, the developed steels with less production cost and reduced deviation of mechanical properties are under commercial production. Note that the developed BH steels are registered as a brand name of MAFE(R) and/or MAF-E(R).