• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.63-69
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• 2011

Exhaust gases of a vessel from a main engine, a diesel generator and an incinerator contain very harmful substances like soot, $SO_2$ and NOx. Careful design of funnel shape is required to prevent those harmful exhaust gases from influencing on accommodation and a fan room. Meanwhile, the exhaust gases are also hot enough to damage electronic devices like radar. Therefore the funnel design should be considered so that electronic devices are not directly exposed to the exhaust gas in the strong stern wind. This study may propose guidelines of optimum design criterion for the anti-thermal damage design of the electronic devices and anti-recirculating design of harmful exhaust gas near the accommodation. From CFD analyses, we can understand that the major factors affecting the exhaust gas dispersion are the large scale mixing by separation vortices and the sluggish flow in the recirculation region. We hope that the funnel flow analysis around ship's funnel is used for practical optimum funnel design to minimize the exhaust gas dispersion by adjusting the funnel shape, the position of the exhaust pipe, the shape of bulwark, the exhaust direction of air ventilated an engine room and the angle of the exhaust pipe.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.24.2-24.2
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• 2009

We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on September 2008. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-time brightness disturbance. For these variations, model spots are applied separately to the two data set of Group I (Sep.--Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel-time (LTT) effect due to the gravitational effect of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body or by the effect of magnetic activity with a cycle length of about 12 yr.

• 천문학회지
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• 제39권1호
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• pp.25-30
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• 2006

We completed four color light curves of the near-contact binary CN And during three nights from September to December 2004 using the 61-cm reflector and BV RI filters at Sobaeksan Observatory. We determined four new times of minimum light (two timings for primary eclipse, two for secondary). Newly obtained BV RI light curves and the radial velocity curves from Rucinski et a1. (2000) were simultaneously analyzed to derive the system parameters of CN And. We used the semi-detached mode 4 of the 2003-version of the Wilson-Devinney binary model, and interpreted the asymmetry of the light curve by introducing two spots; a cool spot on the primary component and a hot spot on the secondary component. New photometric parameters are not much different from those of Cicek et a1. (2005), and it is considered that the system is in the era of broken contact. From the orbital period study with all available timings including our data, we found a continous period decrease with a rate of $P_{obs}=--1.82{\times}10^{-7}\;d\;yr^{-1}$ that can be explained with two possible mechanisms. We think the most likely cause of the period decrease is a thermal mass transfer from the primary to the secondary component, rather than angular momentum loss due to a magnetic stellar wind.

• 농업과학연구
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• 제41권3호
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• pp.251-258
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• 2014

In order to set up the basic environmental control systems which the new concept greenhouses have to equip, greenhouse characteristics, environmental management and control systems in domestic glasshouses and plastic houses were investigated and analyzed comparatively. Survey results on the width, length, eaves height, and the number of spans etc. showed that glasshouses were bigger than plastic houses significantly. New concept greenhouses claim to be plastic houses, but it will be reasonable to follow the specifications of the glasshouse. Specifications to be applied to new concept greenhouses were proposed as follows; hot water heating systems, aluminum screens as the thermal curtain, evaporative cooling systems, roof vents on the ridge, circulation fans, $CO_2$ enrichment, hydroponic systems, and automatic irrigation control systems. Environmental measurement systems for the indoor and outdoor temperature, humidity, light, wind speed and indoor $CO_2$ concentration have to be fully equipped. The automatic control system has to be as a complex environmental control system, not a single item control system. Also, for stable dissemination, domestically producing complete greenhouse control system should be made as soon as possible.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.337-341
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• 2016

Purpose: Evaluation of atmospheric conditions for proper timing of spray application is important to prevent off-target movement of crop protection materials. Susceptible crops can be damaged downwind if proper application procedure is not followed. In our previous study, hourly data indicated unfavorable conditions, primarily between evening 18:00 hrs in the evening and 6:00 hrs next morning, during clear conditions in the hot summer months in the Mississippi delta. With the requirement of timely farm operations, sub-hourly data are required to provide better guidelines for pilots, as conditions of atmospheric stability can change rapidly. Although hourly data can be interpolated to some degree, finer resolution for data acquisition of the order of 15 min would provide pilots with more accurate recommendations to match the data recording frequency of local weather stations. Methods: In the present study, temperature and wind speed data obtained at a meteorological tower were re-sampled to calculate the atmospheric stability ratio for sub-hour and hourly recommendations. High-precision evaluation of temperature inversion periods influencing atmospheric stability was made considering strength, time of occurrence, and duration of temperature inversion. Results and Discussion: The results indicated that atmospheric stability could be determined at different time intervals providing consistent recommendations to aerial applicators, thereby avoiding temperature inversion with minimal off-target drift of the sprayed liquid.

• 대한기계학회논문집
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• 제13권5호
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• pp.991-998
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• 1989

본 연구에서는 충돌각을 변수로 한 실험적 연구를 수행하기 위하여 여타의 변수를 고정하였으며, 유속은 R$_{e}$=5.2*$10^{4}$의 결과를 제시하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.358-363
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• 2008

The spray cross-section characteristics of two-phase spray that using external-mixing nozzle injected into a subsonic cross flow were experimentally studied with various ALR ratio that is $0{\sim}59.4%$. Suction type wind tunnel was used and experiments were conducted to ambient environment. Several plain orifice nozzles with L/d of 30 and orifice diameter of 0.5 mm and orifice length 1.5 mm were tested. Free stream velocity profiles at the injection location were measured using hot wire. Spray images were captured to study collision point and column trajectory. Phase Doppler particle analyzer(PDPA) was utilized to quantitatively measuring droplet SMD, volume flux. Measuring probe of PDPA positions was moved 3-way transverse machine. SMD distributions were layered structure and peaked at the top of the spray plume and low value at bottom of the spray. Volume flux of spray was distributed to the two side region and volume flux quantity decreased when ALR ratio increased. It was found that the perpendicularly injected two-phase spray jet of external mixing into a cross flow showing that mistlike spray moved away from the test section bottom region.

• 한국도로학회논문집
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• 제13권2호
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• pp.139-145
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• 2011

최근 10년간 전세계적으로 아스팔트 포장을 재활용하는 기술이 급속도로 확산되고 있으며 노후 아스팔트 포장을 폼드 아스팔트 또는 유화 아스팔트를 사용하여 현장에서 바로 100% 재활용하는 현장 상온 재생 아스팔트 포장기술이 다양하게 적용되고 있다. 특히, 아이오와 주에서는 교통량이 적은 지방도로에서 기존 포장의 수명을 연장 시켜주는 현장 상온 재생 아스팔트 공법을 많이 적용하고 있다. 일반적으로 현장 상온 재생 아스팔트 포장층은 수분의 침투나 교통하중으로부터 보호하거나 포장설계를 만족시키기 위해 가열 아스팔트 포장으로 덧씌우기를 한다. 일반적으로 현장 상온 재생 아스팔트 포장층 위에 가열 아스팔트 포장으로 덧씌우기 할 시기는 대부분에 감독자들은 일정한 양생기간 또는 최대 함수비에 근거하여 결정하고 있다. 따라서, 본 연구에서는 감독자가 최적에 덧씌우기 아스팔트 포장 시기를 결정할 수 있도록 현장 상온 재생 아스팔트 포장층의 현장 함수비를 간단하게 측정하여 덧씌우기 시기를 결정할 수 있는 수분 감소계수를 개발하는 것이다. 먼저, 현장 상온 재생 아스팔트 포장층의 함수비를 TDR 함수량계를 사용하여 측정하였고 현장 상온 재생 아스팔트 포장이 시공되는 기간 동안에 강우량, 대기온도, 습도, 바람속도 등 기상정보를 수집하였다. 마지막으로 현장 상온 재생 아스팔트 포장의 초기 함수비, 대기온도, 습도, 바람속도를 변수로 하는 수분 감소계수를 개발하였다. 실제 현장 상온 재생 아스팔트 포장에서 측정한 값을 사용하여 개발한 수분 감소계수는 감독자가 연속적으로 현장 상온 재생 아스팔트 포장층의 함수비를 측정하지 않고 최적의 덧씌우기 포장 시점을 결정할 수 있다.

• 대한한방소아과학회지
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• 제12권1호
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• pp.111-131
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• 1998

1. In oriental medicine, the case of sinusitis can be explained, not only external invasion such as PUNG HAN(wind-cold), PUNG YUL(wind-hot), SHUP YUL(damp-heat), but also functional disorder of internal organ such as spleen(脾), lung(肺), kidney(腎) The western medicine classified the cause of sinusitis as two factors. That is bacterial infection factor-Haemophilus influenza, streptococcus pyogeues, streptococcus pneumonia- and viral infection factor-Rhinovirus, parainfluenza, Echo28, Coxsacki21, Sinusitis is complicated to allergic rhinitis, chronic otitis media purulent, chronic tonsilitis, sinubronchitis. On the condition of nasal septum deformity, turbinates deformity, nasal septum deviation, sinusitis can be developed. the predisposing factors of sinusitis is swimming, air pollution, malnutrition, shortage of immunity.2. According to survey, sinusitis occurred that children from 4 to 12 years old and from 5 to 7 years old occupied 70% 3. From the past history data, they experienced chronic tonsillar hypertropy(20%), otitis media, atopic dermatitis, allergic rhinitis, bronchial asthma, pneumonia, bronchiolitis, chronic sore throat, urticaria, milk allergy in sequence. 4. the symptoms of sinusitis is nasal obstruction, postnasal dripping, purulunt(yellow)or white discharge, cough, nose bleeding in sequence. nasal obstruction take the portion of 95%, postnasal dripping 65%, night time or early morning cough 60%. 5. The suffering period of sinusitis is 6 month minimum, 4 years maximum, most cases are included in a year. The suffering period of children was shorter than adult. 6. Diagnosis depend on inspection of nasal cavity, postnasal dripping, X-ray finding. 75% of patient(15case) showed both maxillary sinusitis, 25%(5cases) showed left or right maxillary sinusitis. 7. Treatment of oriental medicine, consist of Herb-medicine, acupuncture and exposing of Lazer beam. Kamihyunggyeyungyotang(加味荊芥蓮翹湯) is administered mainly as the medical therapy, Kamigwaghyangjeungkisan(加味藿香正氣散) Kimizwakwieum(加味左歸飮), Kamihyangsosan(加味香蘇散) is administered for a additional symptoms which occurred by influenza recurrence. Kamijeonxibackchulsan(加味錢氏白朮散) is administered to treat gastro-intestine trouble patients who have sinusitis. 8. The period of treatment is varied with patient conditions and X-ray finding. The minimal period is 35days, maximal period is 202days. So it took about 86days in average and about 50% of patient(10cases) is recovered in one or two month.

• 해양환경안전학회지
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• 제22권5호
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• pp.508-520
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• 2016

본 연구에서는 7년(2009-2015)간 한반도 주변을 통과한 태풍의 이동 경로에 따른 수온의 변동을 분석하였다. 자료는 위성관측 수온영상, 동해 연안의 양양, 강릉, 삼척, 영덕에서 실시간 계류부이에서 관측한 수온과 기상청에서 제공한 바람을 분석하였다. 위성 영상을 이용한 태풍 통과 전후의 근해 수온의 차이는 태풍의 이동 경로에 따른 바람의 방향뿐만 아니라 해면 가열과 해면 상승의 시기와도 관계가 깊게 나타났다. Muifa, Chanhom, Nakri, Tembin과 같은 태풍들의 오른쪽에 위치한 동해 연안의 수온은 남풍계열의 바람에 의한 연안용승으로 표층뿐만 아니라 15m, 25m의 수온까지 하강하는 것을 알았다. 특히, 태풍 Chanhom과 Tembin에 의한 수온의 하강은 각각 $8-11^{\circ}C$와 $16^{\circ}C$ 하강하였다. 한편 그 반대편에 태풍이 위치할 때는 외해쪽에 있는 고온의 해수를 연안쪽으로 이동하여 침강시킴으로서 중층과 저층의 수온이 상승하였다. 또한, 태풍 통과 이후에 동해 연안에서 남풍(북풍)계열의 바람에 의한 하강(상승)된 수온의 혼합은 1-2일 및 4일간 지속되었다.