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Water-hammer in the Pump Pipeline System with and without an Air-Chamber (에어챔버 설치에 따른 펌프관로계의 수격현상)

  • Lee, Sun-Kon;Yang, Cheol-Soo
    • Journal of the Korean Society of Safety
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    • v.26 no.1
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    • pp.1-7
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    • 2011
  • When the pumps stopped in the operation by the power failure, the hydraulic transients take place in the sudden change of a velocity of pipe line. Each and every water hammer problem shows the critical stage to be greatly affected the facts of safety and reliability in case of power failure. The field tests of the water hammer executed at Cheong-Yang booster pump station having an air chamber. The effects were studied by both the practical experiments and the CFD(Computational Fluid Dynamics : Surge 2008). The result states that the system with water hammering protection equipment was much safer when power failure happens. The following data by a computational fluid dynamic analysis are to be shown below, securing the system stability and integrity. (1) With water hammering protection equipment. (1) Change of pressure : Up to $15.5\;kg/cm^2$ in contrary to estimating $16.88\;kg/cm^2$. (2) Change rate of water level : 52~33% in contrary to estimating 55~27%. (3) Note that the operational pressure of pump runs approx. 145 m, lowering 155 m of the regularity head of pump. (4) Note that the cycle of water hammering delays from 80 second to 100 second, together with easing the function of air value at the pneumatic lines. (2) Change of pressure without water hammering protection equipment : Approximate $22.86\;kg/cm^2$. The comprehensive result says that the computational fluid dynamics analysis would match well with the practical field-test. It was able to predict Max. or Min. water hammering time in a piping system. This study aims effectively to alleviate water hammering in a pipe line to be installed with air chamber at the pumping station and results in making the stability of pump system in the end.

Web-Cached Multicast Technique for on-Demand Video Distribution (주문형 비디오 분배를 위한 웹-캐슁 멀티캐스트 전송 기법)

  • Kim, Back-Hyun;Hwang, Tae-June;Kim, Ik-Soo
    • The KIPS Transactions:PartB
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    • v.12B no.7 s.103
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    • pp.775-782
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    • 2005
  • In this paper, we propose multicast technique in order to reduce the required network bandwidth by n times, by merging the adjacent multicasts depending on the number of HENs (Head-End-Nodes) n that request the same video. Allowing new clients to immediately join an existing multicast through patching improves the efficiency of the multicast and offers services without any initial latency. A client might have to download data through two channels simultaneously, one for multicast and the other for patching. The more the frequency of requesting the video is, the higher the probability of caching it among HENs increases. Therefore, the requests for the cached video data can be served by HENs. Multicast from server is generated when the playback time exceeds the amount of cached video data. Since the interval of multicast can be dynamically expanded according to the popularity of videos, it can be reduced the server's workload and the network bandwidth. We perform simulations to compare its performance with that of conventional multicast. From simulation results, we confirm that the Proposed multicast technique offers substantially better performance.

Design and Implementation of a Controllable White Noise Generator for Tinnitus Therapy (이명 치료를 위한 저절형 광역 소음발생개의 설계 및 구현)

  • Yi, Gyu-Dong;Lee, Jeong-Woo;Song, Byung-Seop;Lee, Sang-Heun;Cho, Jin-Ho;Kim, Myoung-Nam
    • Journal of Sensor Science and Technology
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    • v.13 no.1
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    • pp.12-19
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    • 2004
  • The tinnitus which is the one of the auditory disease is a phenomenon that the patients feel the sound in the ear or the head when there is no sound sources. There have been many therapies for this tinnitus so far, but it is known that the TRT (Tinnitus Retraining Therapy) is the most effective therapy. So we designed and developed the controllable white noise generator for TRT. It must be designed as small as possible for user's convenience, such as the ITE (In The Ear) type hearing aids. It used the thermal noise as the white noise source. And filter and tone control circuits are used at the end of the noise generation part to control the white noise characteristics. This link of the controllable circuits is used to change the white noise's characteristic for the various tinnitus patients' characteristic. we can confirm that the designed and implemented controllable white noise generator which is a ITE type operates properly by the experiments of filter and tone control circuit.

in Vitro Embryo Production Following Transvaginal Follicular Oocyte Aspiration from Holstein Cows Using a Simple Aspiration Apparatus (간이 난자채취기를 이용한 젖소로부터 난초란의 채취와 체외수정란의 생산)

  • 김일화;손동수;이호준;이동원;최선호;서국현;양병철;이광원
    • Journal of Embryo Transfer
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    • v.12 no.1
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    • pp.111-116
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    • 1997
  • The present study was carried out to produce in vitro fertilized embryos with immature follicular oocytes collected by transvaginal aspiration from Holstein cows. A simple aspiration apparatus consists of two stainless steel tubes, an inner tube (needle holder; 1.2cmdiameter, 55cm long) and an outer tube (1.5cm diameter, 4Scm long), and a hand-operated vacuum pump was used. Under epidural anesthesia, the needle guide was passed into the vagina of the cow to a point next to the cervix. An ovary was placed against the wall of the vagina over the end of the aspiration needle by rectal manipulation. As the needlepassed into the ovary, an assistant was asked to apply vacuum(l00mrnHg) and the ovary was manipulated back and forth in all directions over the needle. When all sites of the ovary was aspirated, the needle was withdrawn and the needle guide was moved to the other side of ovary and the procedure was repeated. When the oocyte aspiration procedure was finished, collected fluid was transported to laboratory. Oocytes surrounded with at least 1 layer of cumulus cells were matured, fertilized and cultured in vitro. The results were as follows; Ninety seven oocytes were collected by transvaginal aspiration from seventeen Holstein cows(5.7 /head). The number of oocytes surrounded with at least 1 layer of cumulus cells were 60(61.9%). Following in vitro maturation, fertilization and culture, the cleavage and development rate to morula+blastocyst were 83.3% and 30.0%, respectively. From this study, transferable in vitro fertilized embryos could be produced with imma- ture follicular oocytes collected by transvaginal aspiration from Holstein cows using a simple aspiration apparatus.

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An Analysis on the Morphological Relationship of Hair Styles with Changes in Necklines and Collars: From 16th Century to 19th Century

  • Kim, Hyoju;Bae, Soojeong
    • Journal of Fashion Business
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    • v.18 no.3
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    • pp.117-133
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    • 2014
  • This thesis aims to investigate the morphologic relationship among the neckline, collar, and hair style, in which the width and height were measured by selecting the representative costumes from 16th to 19th centuries. The pieces of 170 pictures selected by fashion experts were cut in the same condition, with the part of the end of shoulder, head, and chest all placed on the equal level. The products were directly measured by a team of 3 specialists for verification of this study, of which results were calculated into average. The values of output were categorized into the unit of decade and finally into a graph of variation, in which the trend and relationship were evaluated according to the width and height. In 16th century, the width and height of the neckline were inversely proportional to those of hair style, while those of collar were proportional to those of hair style. In 17th century, the width and height of the hair style were proportional to those of neckline and collar. In 18th century, those of the neckline were inversely proportional to the hair style, with no collar found. In 19th century, the width of the neckline and collar were proportional to that of the hair style, while the height of the neckline and collar were inversely proportional to that of the hair style. The analysis of the morphologic relationship among neckline, collar, and hair style resulting from this study revealed that the change of the hair style took place corresponding to those of neckline and collar. Generally, the width of the hair style was found to be more resistant to change, compared to those of neckline and collar that were more susceptible. The height of the neckline was more resistant to change, compared to those of the hair style and collar presenting their frequently fluctuating height. Conclusively, the factor of height rather than that of width showed more dominant proportions, because the various forms of the collar and hair style evolved in terms of the height rather that width, relative to that of the neckline.

A Study of the Costumes and Make-up in the Movie "Anna Karenina"

  • Jung, Jeewon;Kim, Eunsil
    • Journal of Fashion Business
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    • v.19 no.3
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    • pp.14-30
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    • 2015
  • The purpose of this study is to establish how main characters' mental states are expressed through costumes and makeup by understanding and analyzing the relationship between the costumes and the makeup in the movie "Anna Karenina" and to compare the 19th century Russian costumes. The study methods are a literature review and an empirical case study. The results are as follows. First, the costumes in "Anna Karenina" are a mixture of late crinoline and early bustle style in general. However, the costumes were altered after the actress's movements and acting were considered. Regarding colors, Anna wears a lavender robe as the virtuous wife, a wine-colored robe for love and death, and a white robe for innocence, thus reflecting her mental states; through the colors, her changes of mental state are expressed. Second, the costumes of Alexei Vronsky, are similar in style and colors to those of mid-late 19th century Russian military uniforms. White, blue and black costume colors are used to describe his situations and emotional changes. Third, Alexei Karenin wears 19th century costumes of dark and achromatic colors without decorations, representing his conservative, authoritative character. However, he showshis rage with a wine and red-colored costume at the end of the movie. Fourth, regarding the makeup in the movie, Anna wears makeup of a soft pink-gold color influenced by 19th century naturalism. Male characters express their characteristics with their beards and hair styles. Vronsky's Hollywood mustaches and wavy blonde hair show his charm, and Karenin's chin curtain beard and bald head reveal his conservative character. The costumes of the three main characters in the movie are not very different from 19th century style in general, but mental states and situations are expressed through accessories, and colors maximize all of the effects. Through this research, it is illustrated that the costumes and makeup in a movie can not only express characters' emotional changes but also show the relationships between the characters in different scenes.

A study on the body types of women's models in their 20s for making clothes for fashion models (패션모델용 의복 제작을 위한 20대 여성 모델 체형 연구)

  • Lee, Moon-Suk;Park, Myung-Ja;Uh, Mi-Kyung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.20 no.4
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    • pp.31-40
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    • 2018
  • The purpose of this study is to identify the body type characteristics of fashion models by comparing body dimensions and body types of fashion models with ordinary women in their 20s in Korea. To that end, the study selected 71 people, with 28 being female university students in the Seoul area and 43 professional fashion models. One hundred and fifty-seven ordinary woman were selected who ranged from 20 to 29 years old, and 588 women from the 7th Size Korea fit for research purposes. Body measurement items were selected for the direct measurement data for Size Korea, which included 20 items of body size and 10 items of calculation needed for clothing production. The results of the study were as follows. According to the analysis of fashion models and ordinary woman in their 20s, their body size showed significant differences in 25 out of 30 items. The five items that do not show significant differences are bust point-bust point, waist back length, front interscye length, hip circumference-bust circumference, and neck point to bust point to waistline-waist front length. If you integrate the results, the fashion model is much taller than the ordinary woman, has a longer lower body, and has an 8.05 head figure. Also, the fashion model found itself to be the ideal type that ordinary women prefer because of the slimmer waist and bent shape, which is more than that measured in normal women.

Comparison of complete surgical excision and minimally invasive excision using CO2 laser for removal of epidermal cysts on the face

  • Kim, Keun Tae;Sun, Hook;Chung, Eui Han
    • Archives of Craniofacial Surgery
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    • v.20 no.2
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    • pp.84-88
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    • 2019
  • Background: Epidermal cysts are benign, slow growing cysts that often develop on the head, neck, chest, and back of adults. The most common method of surgical excision involves the use of a scalpel and often leaves a scar proportional to the size of the cyst. Therefore, minimally invasive techniques are required. Among these techniques, the $CO_2$ laser-based technique is minimally invasive and has lower complication rate, shorter recovery times, and lesser scarring. This paper aimed to compare the results and postoperative complications associated with a $CO_2$ laser-based excision against conventional surgical excision for epidermal cysts. Methods: We surveyed 120 patients, aged 16 to 65 years, with epidermal cysts on the face measuring 0.5 to 2.2 cm in diameter. Twelve months later, we compared the scar length, recurrence rate, patient satisfaction, and complications between patients treated with $CO_2$ laser excision versus surgical excision. Results: The mean scar length (12 months postoperative) after $CO_2$ laser excision was $0.30{\pm}0.15cm$, and that following surgical excision was $1.23{\pm}0.43cm$ (p= 0.001). The procedure time (time from incision after local anesthesia to the end of repair) was $16.15{\pm}5.96minutes$ for $CO_2$ laser excision versus $22.38{\pm}6.05minutes$ for surgical excision (p= 0.001). The recurrence rates in the surgical excision group and $CO_2$ laser excision group were 3.3% and 8.3%, respectively; this difference was not statistically significant (p= 0.648). Conclusion: The cosmetic outcome of $CO_2$ laser excision is excellent. For epidermal cysts measuring 2.2 cm or smaller, $CO_2$ laser excision is recommended, especially when aesthetic outcome is considered important.

Influence of zirconia and titanium fixture materials on stress distribution in abutment screws: a three-dimensional finite element analysis (지르코니아 및 티타늄 고정체 소재가 지대주 나사의 응력 분포에 미치는 영향: 3차원 유한 요소 분석)

  • Kim, Eun Young;Hong, Min-Ho
    • Journal of Technologic Dentistry
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    • v.43 no.2
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    • pp.42-47
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    • 2021
  • Purpose: The purpose of this study was to evaluate the stability of abutment screws used with the zirconia fixture-based implant system and compare them with those used with the existing titanium fixture system via the finite element method. Methods: A single implant-supported restoration was designed for the finite element analysis. A universal analysis program was used to set 8 occlusal points along the direction to the long axis of the implant, and an occlusal load of 700 N was applied. Results: In all models (Zir and Ti-fixture model), the screw threads presented with the highest von Mises stress (VMS) values, whereas the head and end presented with the lowest VMS values. The VMS of the screw used in the zirconia-fixture model was 5.97% lower than that used in the titanium-fixture model (261.258 vs. 276.911 MPa, respectively) despite statistical significance. Furthermore, the zirconia fixture (352.912 MPa) had a higher stress value (8.42%) than the titanium fixture (332.331 MPa). In a completely tightened titanium fixture implant system, the stress was concentrated in the implant-abutment connection interface, the zirconia fixture presented with a stable stress distribution. Conclusion: Although the zirconia fixture demonstrated a high VMS value, owing to the stiffness and elasticity coefficients of the material, the stress generated in the abutment screws was similar in all models. In conclusion, the zirconia fixture-based implant system presented with a more stable stress distribution in the abutment screws than the titanium fixture-based implant system.

『The Death of a Salesman』 reinterpreted by Media Transformation: Focusing on (2017) by Asghar Farhadi (매체 변환을 통해 재해석된 『세일즈맨의 죽음』: 아쉬가르 파라디 감독의 영화 <세일즈맨>(2017))

  • Choi, Young-hee;Lee, Hyun-Kyung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.4
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    • pp.193-198
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    • 2022
  • Arthur Miller's play has been reproduced for a long time, and has been made into a film several times. Director Asghar Farhadi made a film set in Iran in the 21st century, showing the film (2017), which excludes "Death" from the original title. is not just a movie of . In , the play is summoned in the form of performing a play. There are many movies in this form, but is an exquisite fabrication so that the reality outside the play and the content in the play harmonize with each other. The play depicts the tragedy of the head of the family who falls at the end of the American dream. The movie transforms this tragedy into a conflict between a young couple living in Iran in the 21st century. In addition, is completed as an independent work that not only rearranged the space and characters of the original work, but also reinterpreted the meaning of death, creating the effect of media conversion such as theater and film.