• 한국농공학회논문집
• /
• 제56권6호
• /
• pp.121-128
• /
• 2014

Development of the economic methods and the design of the standard sections needs the more project fund and land than ever leads to the objection of enlarging canal arrangement to need economic construction method development and standard design for supporting it. The objective of this study was to evaluate the performance of selected sediment reduction methods to reduce sediment discharges from drain and irrigation of different land types (Mountain, Flatten, Reclaimed land). This study was carried out to analysis for the soil loss and sediment of drain and irrigation by comparing RUSLE method and amount of sediment from amount of dredging data of Korea Rural Corporation. The results of study were analyzed and summarized as follow. Size of soil sediment from the upper region of drain and irrigation of mountains bigger than lower region. But in case of flatten and reclaimed land, size of soil sediment from the upper and lower region of drain and irrigation did not classified. In case of comparison drain and irrigation without classifying of land type, size of soil sediment from irrigation is bigger than drain.

• 한국안전학회지
• /
• 제14권1호
• /
• pp.78-85
• /
• 1999

The removal characteristics of H$_2$S from IGCC process over the natural manganese ore(NMO) containing several metal oxides($MnO_x$ : 51.85%, $FeO_y$ : 3.86%, CaO : 0.11%) were carried out in a batch type fluidized bed reactor(I.D.=40mm, height=0.8m). The $H_2S$ breakthrough curves were obtained as a function of temperature, initial gas velocity, initial gas concentration, and aspect ratio. The effect of particle size ratio and particle mixing fraction on $H_2S$ removal were investigated with binary system of different particle size. From this study, the adsorption capacity of $H_2S$ increased with temperature but decreased with excess gas velocity. The breakthrough time for $H_2S$ is reduced as the gas velocity is increased which leaded to gas by-passing and gas-solid contacting in a fluidized bed reactor. The results of the binary particle system with different size in batch experimental could predict to improve the behavior of continuous process of $H_2S$ removal efficiency. The natural manganese ore could be considered as potential sorbent in $H_2S$ removal.

• 교육시설
• /
• 제9권3호
• /
• pp.13-21
• /
• 2002

The new design concept for the middle school is developed as the seventh curriculum is published. However, the credible data for a plan study and spatial organization, and the type of rooms, and using area are hardly found. On this background, the purpose of this study is to provide fundamental resources for the design of middle schools and to recognize national status of plan organizations of middle schools with analizing the space and the type of rooms of collecting 150 schools' architectural plan drafted by city, province education office for 4 years(from 1997 to 2000) As a result, we know that although the class size of school is same, the area for school buildings is very diverse. Then, in order to increasing the area and to develop school buildings' quility, the meaning of standard level should be changed urgently minimum size to optimun size.

• Journal of Chest Surgery
• /
• 제54권5호
• /
• pp.338-341
• /
• 2021

As diagnoses of small ground glass nodule (GGN)-type lung adenocarcinoma are increasing due to the increasing frequency of computed tomography (CT) screening, surgical treatment for GGN-type lung adenocarcinoma has rapidly become more common. However, the appropriate surgical extent for these lesions remains unclear; therefore, several retrospective studies have been published and prospectively randomized controlled trials are being undertaken. This article takes a closer look at each clinical study. Convincing evidence must be published on 2 issues for sublobar resection to be accepted as a standard surgical option for GGN lung adenocarcinoma. In the absence of such evidence, it is better to perform lobar resection as long as the patient has sufficient lung function. The first issue is the definition of a sufficient resection margin, and the second is whether lymph node metastasis is conclusively ruled out before surgery. An additional issue is the need for an accurate calculation of the total size and solid size on CT. Given the results of clinical studies so far, wedge resection or segmentectomy shows a good prognosis for GGNs with a total size of 2 cm or less. Therefore, sublobar resection will play a key role even in patients who can tolerate lobectomy.

• 한국산업융합학회 논문집
• /
• 제26권4_2호
• /
• pp.571-576
• /
• 2023

In this study, the harmless crack size(a_hml) according to the residual stress depth was evaluated using the fatigue limit of SCM440 steel by quenching-tempering(QT) and induction hardening(IH), and threshold stress intensity factor of QT steel. Because the residual stress increased rapidly as the crack depth increased, a_hml was determined at the depth of all the crack aspect ratio(As) regardless of Type I-III, and a_hml also increased according to the residual stress depth. a_hml was minimal at As=1.0 and maximal at As=0.1, but was almost similar on each Type. a_hml was small the dependence on As.

• 대한가정학회지
• /
• 제42권6호
• /
• pp.103-110
• /
• 2004

Among accessaries, headwear is important to protect one's face and head from the sun, wind and cold. This study was performed to provide fundamental data on college female students' head shape by classifying their head shapes and by analyzing the characteristics of each head shape in order to improve the fitness of headwear. The subjects were 193 Korean college female students. The subjects were directly measured anthropometrically and indirectly analyzed photo-graphically. By direct and indirect measurement, 5 factors were extracted through factor analysis and those factors comprised 76.34% of the total variance. 3 clusters as their head shape were categorized using 5 factor scores by cluster analysis. Type 1 was characterized by long head type and having smallest head thickness and head girth. Type 2 had average size and the most round-head type. Type 3 was characterized by short head type and the largest head thickness and head girth.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.550-553
• /
• 2008

In this paper, experiments of air-breathing proton exchange membrane fuel cell (PEMFC) for mobile devices were carried out according to the cathode conditions. These conditions are defined by the cathode flow field plate type (the channel type, the open type) and the cathode surface direction. Single cell and 6-cell stack were used in this experiments. The experimental results showed that the open type cathode flow field plate gave better performance for small size PEMFCs because the open type cathode plate allowed better air convection than the channel type cathode plate. In the experiments related to the direction of the slits on the cathode flow field plate, the horizontal slit cell was better than the vertical slit cell. With respect to the cathode surface direction, when the cathode surface is placed in the direction normal to the ground, PEMFC generated more stable power in the mass transport loss region.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.313-318
• /
• 1999

This study is aim to evaluate of the flexure toughness of fiber reinforced concrete with ring type steel fiber. The experiment proceeding ASTM C 78 is performed to make a comparision between the ring type flber and the double-hook type fiber which is recently come in to use. The size of the test specimen is 10$\times$10$\times$35mm and the flexture test is proceeded by third-point loading method. The test lasts until 2mm deflection and the loading speed is 0.01mm/min by deflection control. From the experimental results, the specimens with ring type fiber of 30kg/㎥ and 30mm diameter of ring circle show much higher toughness indices than those of the double-hook type fiber of 30kg/㎥ and 30mm long.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권2호
• /
• pp.243-251
• /
• 2004

Absorption chiller/heater can utilize the unused energy of the daily life waste heat, the industry waste heat. the solar energy and the earth energy. These can contribute to energy savings. But the absorption chiller/heater has a demerit that the size of absorption chiller/heater is larger than that of the vapor compression type based on same capacity. In this study. the experimental apparatus of an absorber is manufactured as a plate. which is newly applied in an absorber. The experimental apparatus is composed of a plate type absorber. which can increase the heat exchange area per unit volume and thus facilitating to deeply investigate more detail features instead of that done by the existing type. i.e.. horizontal tube bundle type. The characteristics of heat transfer and refrigeration capacity are studied experimentally. The absorption enhancement by using surfactant is closely examined through the experiment and comparative figures are presented in quantitative and qualitative analysis.

• 대한기계학회논문집B
• /
• 제27권9호
• /
• pp.1256-1261
• /
• 2003

Since the viscous effect increases as the size of device decreases, viscous-driven micropump is a promising mechanism in microscale applications. In the present study, a dual-rotor type pump which contains two counter-rotating cylinders for improving performance characteristics is proposed. First, for flows in the single-rotor type pump, the present unstructured grid simulation method is validated by comparing its results to the previous results. Next, the performance of the dual-rotor type pump is evaluated by the parametric studies and is compared to that of the previous single-rotor type pump. The flow characteristics are qualitatively similar to those of single-rotor type pump. However, the performance of the micropump with tandem rotors is still better than that of previous pumping type, e.g. much larger flow rate, smaller driving region, higher efficiency, and wider operation range.