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Experimental Study on the Cooling and Heating Characteristics of System A/C Applying the Digital Scroll Compressor (디지털 스크롤 압축기를 적용한 시스템 에어컨의 냉난방특성에 대한 실험적 연구)

  • Jeon, Yong-Ho;Kim, Dae-Hoon;Kwon, Young-Chul;Jang, Geun-Sun;Lee, Yoon-Soo;Moon, Je-Nyung;Yoon, Baek;Hong, Ju-Tae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.6
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    • pp.454-460
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    • 2003
  • In order to investigate the cooling and heating characteristics of a variable-capacity system A/C applying a digital scroll compressor, the cooling and heating capacities and COP are measured by the psychrometric calorimeter. The capacity of the system is controlled by the digital scroll compressor, which is operated by controling PWM valve and the loading vs. unloading time. In the case of unloading compared that of loading, the consumption power of the compressor is about 11% and the capacity variation of the system A/C is within about 1%. When the system A/C is operated under the cooling and heating standard conditions, COP is nearly uniform but cooling capacity and heating capacity increase at minimum, rated and maximum modes. The system A/C applying the digital scroll compressor is effective for the range with high load or the width of large load variation. When the auxiliary heater is on, at the cold region, the system A/C produces the excellent heating capacity.

Flowering and Maturing Response to Seeding Date and Short-day Treatment in Vegetable Perilla (잎들깨의 개화 및 결실에 미치는 파종기와 단일처리의 영향)

  • 한상익;곽재균;오기원;배석복;김정태;곽용호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.4
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    • pp.466-472
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    • 1997
  • Vegetable perilla, "Ipdlkkae 1"(Perilla frutescens var japonica Hara), was tested about the flowering and maturing responce in summer and winter. In summer season, it was researched about those responses according to the change of seeding date from May 15th to Oct. 15th at one month interval in the field. "Ipdlkkae 1" flowered Oct. 2nd under the day length of eleven hours and fourty-one minutes, compared with Sep. 6th (day length of twelve hours and fourty-three minutes) of "Yepsildlggae". And those responses showed that vegetable perilla was have to seeded before July 15th for two reason. The first is a unique response of perilla to day length. If perilla stay under short-day condition for some days, perilla will flower after four weeks. The second is a weather, especially frost and cold. In the test of latest seeding at Oct. 15th, the plants flowered more late than normal flowering period and they were not able to mature for frost of early winter. And this result showed that any other species, which has the characteristic of later flowering than that of "Ipdlkkae 1", could not able to mature in the field. In winter time, this species was tested about the same responses according to the change of short-day treatments. In the case of the test from May 1st (above fourteen hours day length), even if the test plants were stayed under short-day condition for more than 10 days, they were not able to mature, but flowerd. From the test of Apr. 15th, day length of thirteen hours, the plants were showed variable reaction to the short-day treatment. In this test, 11days for short-day treatment was a basic day to decide whether flowering was delayed or not. In the test from Apr. 1st, perilla seeds were able to harvest at least 5 days short-day treatment. In the final test from Mar. 15th, it had no need to take short-day treatment for harvesting of normal seeds, because the day length of that are twelve hours, which is an enough time to induce flowering and maturing, previously reported.

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The Sensibility Effects of Color Combination and Layout in the Design of Web Site (웹 디자인에서 배색과 레이아웃에 대한 감성효과)

  • 조경자;선지현;한광희
    • Archives of design research
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    • v.17 no.2
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    • pp.209-220
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    • 2004
  • This research was conducted to see the effect of color combination and layout in the design of web sites. Eight color combination samples and four basic layouts were selected and web pages designed from their combinations were used in the experiment. The main sensibility effects were found in the 'light, soft, and rich' color combination and in the 'light, dear, simple, warm, neat, and soft layout, respectively. Among the combinations of two factors, the combination of 'dark, hard, and simple' color combination and 'cold, somber, hard, and urban' layout had the sensibility effect. The results showing sensibility word with the sensibility of color combinations in themselves appeared first implies that much of the sensibility effects were caused by the color combinations. In case of layout, as it went from layout A to layout B, to layout C, and to layout D, that is, as the layout got more complicated, it had a 'rich and urban' impression. As a result, the sensibility effect caused by color combination was bigger than the sensibility effect caused by layout. However, layout is crucial in color combinations, it is also important in the design of web sites.

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Glomus Tumors of the Fingers -A Report of 66 Cases - (수지의 사구체 종양 - 66예 증례 분석 -)

  • Chon, Han-Kyong;Roh, Hyong-Rae;Lee, Han-Dong;Lee, Yu-Sang
    • Archives of Reconstructive Microsurgery
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    • v.21 no.1
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    • pp.50-55
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    • 2012
  • Purpose: We reviewed 66 cases of the glomus tumors in the hands. The purpose of this study was to review the characteristic signs and symptoms of glomus tumors and the surgical outcomes. We made hypothesis that (1) our guideline for surgical excision are reliable and (2) our surgical technique is efficient and less harmful to the nail root. Materials and Methods: The clinical diagnosis was made with occasional radiological studies and surgical excision was performed according to our indications. Patients with electrical shock-like pain by touching (the essential symptom) and at least 2 of 4 clinical signs and symptoms (cold hypersensitivity, paroxysmal pain that radiated proximally, blue discoloration, nail deformity for dorsal tumor or a palpable nodule for pulp tumor) underwent surgical excision. Results: The duration of symptoms of the patients was about 5.3 years. No difference of prevalence was found in both hands, but the thumb and the middle finger were more affected than the other fingers. The mean follow up period was 2.4 years and none of the patients complained the same characteristic pain at the last visit. Conclusion: To the best of our knowledge, this report is the largest case series about glomus tumors in the finger tip. The clinical signs and symptoms are important to make a diagnosis of glomus tumors, and surgical excision is the treatment of choice.

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Measurements of Thermal Diffusivity of Heavy Rolled Low Carbon Steel Plate With Laser Flash Technique (레이저 섬광법에 의한 압연된 저탄소강 판재의 열확산계수 측정)

  • 배신철;임동주
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.1
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    • pp.157-171
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    • 1990
  • The heat transfer problem associated with pulse technique for measuring thermal diffusivity was solved by means of Green function. The obtained general solution was discussed so as to apply for all possible cases; kinds of boundary condition and heat source, irradiation positions of heat pulse, radius of heat pulse, one-and two-dimensional heat flow, finite pulse time effects and radiation heat loss systems. Experimentally, the laser flash lamp was used as heat source for measuring thermal diffusivity of low carbon, aluminium chilled steel plate, which was heavily rolled in order to measure the variation of thermal diffusivity in the temperature range from room temperature through 500.deg. C. The derived results are (1) materials produced from same furnace showed a somewhat different thermal diffusivity values. (2) the thermal diffusivity value of rolled material was smaller than unrolled material and the difference decreased as increasing temperature. (3) the thermal diffusivity value of an annealed and temper rolled material was larger than the value of a cold rolled material, even thought smaller than unrolled material. (4) In case of heavy rolled material, there was no consistent relationships between the thermal diffusivity and the reduction in thickness.

Atmospheric Icing Effects on the Aerodynamic Characteristics and Performance of Wind Turbine Blade (풍력 블레이드의 결빙에 의한 공력특성 및 성능 변화)

  • Park, Ji-Ho;Myong, Rho-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.2
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    • pp.134-143
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    • 2014
  • A significant degradation in the aerodynamic performance of wind turbine system can occur by ice accretion on the surface of blades operated in cold climate. The ice accretion can result in performance loss, overloading due to delayed stall, excessive vibration associated with mass imbalance, ice shedding, instrumental measurement errors, and, in worst case, wind turbine system shutdown. In this study, the effects of ice accretions on the aerodynamic characteristics of wind turbine blade sections are investigated on the basis of modern CFD method. In addition, the computational results are used to predict the performance of three-dimensional wind turbine blade system through the blade element momentum method. It is shown that the thickness of ice accretion increases from the root to the tip and the effects of icing conditions such as relative wind velocity play significant role in the shape of ice accretion.

Peritonitis associated with Streptococcus equi subsp. zooepidemicus in a thoroughbred horse (더러브렛 말의 Streptococcus equi subsp. zooepidemicus 감염에 의한 복막염)

  • Cho, Jung-Joon;Kang, Sang-Chul;Yang, Hyoung-Seok;Yang, Jae-Hyuk;Son, Won-Geun;Bae, Jong-Hee;Kim, Jae-Hoon
    • Korean Journal of Veterinary Research
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    • v.47 no.3
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    • pp.315-319
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    • 2007
  • Fibrinopurulent peritonitis and abdominal abscesses associated with Streptococcus (S.) equi subsp. zooepidemicus is reported in a 1-year-old female thoroughbred horse. The horse died after showing 5-day history of the cold, severe abdominal distention, abdominal breathing, hyperthermia, anorexia, and loss of intestinal sound. At necropsy, several liters of turbid yellowish green fluid were seen in the abdominal cavity. Yellowish creamy and fibrinous or bloody materials were presented on the serosa of various abdominal organs that were intensively adhered with each other. Spleen and mesenteric lymph node were remarkably enlarged. Affected lobes of the lung showed severe congestion, hemorrhage and doughy consistency. Histologically, the lung showed hemorrhagic pneumonia with diffuse congestion and edema. Severe diffuse fibrinopurulent peritonitis with Gram-positive bacterial cocci and adjacent fibrosis were showed in the serosa of various abdominal organs such as liver, spleen, stomach, and intestine. And multifocal abscess pouches were presented in the granulation tissue of abdominal viscera. S. equi subsp. zooepidemicus was isolated from the peritoneal swab, abdominal organs, and lung. Hematogenous dissemination of bacteria from hemorrhagic pneumonia is proposed as the route of infection in this case.

Temperature and Dependence of the Microhardness of Rhenium Sheets (리늄판의 미세경도 온도 및 응력의존성)

  • Yun, Seok-Yeong;Lagerlof, K.P.D.
    • Korean Journal of Materials Research
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    • v.10 no.5
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    • pp.335-342
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    • 2000
  • The microhardness of rhenium sheets was determined as a function of indentation load and temperature. The temperature dependence of the microhardness between room temperatures and $1000 ^{\circ}C$was studied using a hot microhardness tester equipped with a Vickers indenter. The load dependence of the microhardness was investigated using oth a Vickers and a Knoop indenter. The indentation size effect (ISE) was well explained using the normalized Meyers law. The hardness of the annealed rhenium sheet approached that of the as-rolled sheets at large indentation loads because of work-hardening under the indenter during indentation. The hardness at zero load(obtained from extrapolation of the load dependence of the hardness) suggested that the hardness is controlled by two different mech-anisms having different thermal activation. At low temperature the activation energy for the mechanism controlling the hardness was approximately 0.02 eV , Whereas at higher temperatures that was approximately 0.15eV. The tranisi-tion temperature between the two different controlling mechanisms was about $250^{\circ}C$.

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Exploratory Spatial Data Analysis (ESDA) for Age-Specific Migration Characteristics : A Case Study on Daegu Metropolitan City (연령별 인구이동 특성에 대한 탐색적 공간 데이터 분석 (ESDA) : 대구시를 사례로)

  • Kim, Kam-Young
    • Journal of the Korean association of regional geographers
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    • v.16 no.5
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    • pp.590-609
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    • 2010
  • The purpose of the study is to propose and evaluate Exploratory Spatial Data Analysis(ESDA) methods for examining age-specific population migration characteristics. First, population migration pyramid which is a pyramid-shaped graph designed with in-migration, out-migration, and net migration by age (or age group), was developed as a tool exploring age-specific migration propensities and structures. Second, various spatial statistics techniques based on local indicators of spatial association(LISA) such as Local Moran''s $I_i$, Getis-Ord ${G_i}^*$, and AMOEBA were suggested as ways to detect spatial dusters of age-specific net migration rate. These ESDA techniques were applied to age-specific population migration of Daegu Metropolitan City. Application results demonstrated that suggested ESDA methods can effectively detect new information and patterns such as contribution of age-specific migration propensities to population changes in a given region, relationship among different age groups, hot and cold spot of age-specific net migration rate, and similarity between age-specific spatial clusters.

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Clinical evaluation of Acupuncture on Herniated of Cervical Intervertebral Disc by DITI (컴퓨터 적외선(赤外線) 전신체열촬영(全身體熱撮影)으로 본 경추추간판(頸椎椎間板) 탈출증(脫出症)의 침구치료효과(鍼灸治療效果))

  • Lee, Geon-Mok
    • The Journal of Korean Medicine
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    • v.16 no.1 s.29
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    • pp.132-140
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    • 1995
  • Object : This study is designed to evaluate the correlation between the data of DITI(Digital Infrared Thermographic Imaging)examination and the changes of clinical symptom after the therapy of acupuncture in the patients with herniated cervical intervertebral disc. Content : The conservative therapy with acupuncture was performed during $4{\sim}5$ weeks, The acupuncture points of SI3, B62, TE3, G34, LI4, S36, GV26, G21, SII5 were used. In the pre- and post therapy, DITI examinations were performed in patients who had HIVD and were treated by acupuncture simultaneously, and then tried to correlate the results of clinical symptoms with the difference of thermographic findings at pre-acupuncture and post-acupuncture. Setting : The standard routine thermoghaphic examinations were performed with thermography(DITI) in the 15 patients with lumbar disc herniations at pre- and post acupuncture. Patient : Thermographic imaging of 15 cases were analyzed. They has disc herniations in X-ray, CT scan and MRI and they were treated by acupuncture theraphy in our hospital from March, 1994 to January, 1995. Result : 1) The causes were trauma(60%), retention of phlegm and fluid(8.7%) and cold & moisture(33.3%) 2) Levels of herniated cervical disc are C2/3(1 case). C3/4(2 cases), C5/6 & C6/7 (2 cases), C6/7(4 cases), Normal(6 cases). 3) Classifications of thermographic pattern are radiculopathy(80%), spot(13.3%), and nonspecific(6.7%) in order. 4) In evaluation Results of clinical symptom are Excellent(80%), Good(6.7%), and Poor(6.7%). Data of DITI are Excellent(80%), Good(6.7%), Fair(6.7%), and Poor(6.7%). Conclusion ; Acupuncture showed good results over 86.7% in clinical evaluation and 86.7% in DITI. Thermographic examination was valuable in the evaluation of therapeutic effect of acupuncture treatment.

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