• 대한기계학회논문집B
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• 제28권11호
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• pp.1390-1397
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• 2004

This study is concerned with the thermal analysis during the cool-down period of 135,000㎥ class GT-96 membrane type LNG carrier under IMO and USCG design condition. During the cool-down period, the spraying rate for the NG cooling decreases as the temperature of NG falls down from -4$0^{\circ}C$ to -l3$0^{\circ}C$, and the spraying rate for the cooling of the insulation wall increases as the temperature gradient of the insulation wall is large. It was confirmed that there existed the largest temperature decrease at the first barrier and the first insulation, which are among the insulation wall, especially in the top side of the insulation wall under IMO and USCG design condition. Also, as the NG temperature distribution is fixed, the outer temperature condition under the design condition has influence on the temperature variation at the insulation. By the 3-D numerical calculation about the cargo tank and the cofferdam during the cool-down period, the temperature variation in hulls and insulations is precisely predicted under IMO and USCG design condition. From the comparison between two conditions; IMO design condition shows more severe temperature gradient than USCG design condition, therefore, it provides the conservative estimation of the BOG.

• Tribology and Lubricants
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• 제25권6호
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• pp.367-373
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• 2009

Many research of elastohydrodynamic lubrication (EHL) has been performed under the condition of steady state loading. However, mechanical elements undergo severe high loads that are in the fluctuating modes of frequency and amplitude. Conventional numerical method for the circular contact of EHL study has the difficulty in making the film thickness and pressure of EHL converged in high loads of steady state as well as fluctuating loading conditions. In this work, multigrid multilevel method are used for the stable convergence of film pressure and thickness under the conditions of high as well as varying loads, and very stable solutions of film behaviors with elastic deformation are obtained. Several results of dynamic loading condition are shown and compared with those of steady state condition in the aspects of circular EHL film thickness and pressure.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.636-639
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• 1996

We have developed a part of hydraulic stroke sensing cylinder using magnetic sensor that can detect each position under severe construction fields. In this paper, for evaluating the developed cylinder under various environment condition, thermal control systems and two hydraulic systems to be coupled consist of. The former is composed of an heater case, temperature sensor, and interface circuits which include SCR(silicon controlled rectifier) for the control of the voltage's phase. The latter is composed of an hydraulic cylinder for position control with solenoid valve (ON/OFF motion) and a load cylinder with proportional reducing valve. To obtain the various performance evaluation, it is carried out under high temperature condition in thermal system controlled by using Ziegler-Nichols PID tuning method and artificial disturbances such as impulse or constant force. The results show that the developed cylinder has good performance under the various environment condition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.14-19
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• 2005

An accelerated life test (ALT) is used to estimate the reliability of machinery parts and system with a design specification as soon as possible. However, accelerated life test results with simple and severe conditions are inconsistent with physical phenomena in real service condition. Therefore, to assure the safety of the machinery system, it is necessary to establish the appropriate test condition of the ALT of machinery element. In this study, fatigue analysis of the spur gear as a part of the gear box system in the rolling stock was performed. Moreover, based on the results, appropriate test condition of the ALT is developed using both the probabilistic model of the linear damage rule and accelerated durability analysis simulation.

• Nuclear Engineering and Technology
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• 제44권3호
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• pp.237-248
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• 2012

Corium behavior in the lower plenum of the reactor vessel during a severe accident is very important, as this affects a failure mechanism of the lower head vessel and a thermal load to the outer reactor vessel under the IVR-ERVC (In-Vessel corium Retention through External Reactor Vessel Cooling) condition. This paper discusses the state of the art and technical issues on corium behavior in the lower plenum, such as initial corium pool formation characteristics and its transient behavior, natural convection heat transfer in various geometries, natural convection heat transfer with a phase change of melting and solidification, and corium interaction with a lower head vessel including penetrations of the ICI (In-Core Instrumentation) nozzle are discussed. It is recommended that more detailed analysis and experiments are necessary to solve the uncertainties of corium behavior in the lower plenum of the reactor vessel.

• Journal of Information Processing Systems
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• 제14권1호
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• pp.191-204
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• 2018

To combat the adverse impact imposed by illumination variation in the face recognition process, an effective and feasible algorithm is proposed in this paper. Firstly, an enhanced local texture feature is presented by applying the central symmetric encode principle on the fused component images acquired from the wavelet decomposition. Then the proposed local texture features are combined with Deep Belief Network (DBN) to gain robust deep features of face images under severe illumination conditions. Abundant experiments with different test schemes are conducted on both CMU-PIE and Extended Yale-B databases which contain face images under various illumination condition. Compared with the DBN, LBP combined with DBN and CSLBP combined with DBN, our proposed method achieves the most satisfying recognition rate regardless of the database used, the test scheme adopted or the illumination condition encountered, especially for the face recognition under severe illumination variation.

• 소성∙가공
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• 제32권5호
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• pp.247-254
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• 2023

This study conducted the wear tests on bending punches coated with PVD CrN and examined the surface quality of the product formed by each punch in the forming of uncoated TRIP1180 sheets. The study quantitatively estimated the surface quality of the product by measuring the roughness and imaging the product surface. The correlation between the punch wear depth and the product surface roughness was quantitatively analyzed. The results showed that before failure occurs, the product roughness was comparable with that of the as-received, and the product surface was smooth without scratches and defects. However, after failure, the punch wear is caused by fretting wear mechanism, and a punch whose coating is not completely peeled plows the product surface, resulting in severe scratches with grooves and ridges on the product surface. Severe wear on the punch surface caused by fretting wear can rapidly degrade the product surface quality as it is directly affected by the punch surface condition, and the product surface quality accurately reflects the punch wear condition.

• 사상체질의학회지
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• 제24권4호
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• pp.28-39
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• 2012

Objectives : This study is aimed to develop the algorithm to diagnose Taeeumin's symptomology, by the method of literature research on Sasang Constitutional Medicine. Methods : Applying the sequential differentiations of Taeeumin's symptomology, or exterior-interior disease differentiation, favorable-unfavorable pattern differentiation, and mild-severe-dangerous-urgent pattern differentiation, "Donguisusebowon" and related literatures have been reviewed. Results and Conclusions : 1) 1st step: Taeeumin's exterior pattern and interior pattern are differentiated by the indexes of whole-body cold or heat pattern, sweating, and facial complexion. 2) 2nd step: The favorable pattern of the Taeeumin's exterior disease can be detected by indexes of the existence of fever, generalized pain while the unfavorable one by indexes of the abnormal condition of digestion and feces, and fearful throbbing. The favorable pattern of the Taeeumin's interior disease can be diagnosed based on indexes of eye pain, dry nose, dry throat, and heat symptoms that occur in various parts of the body, while the unfavorable one by indexes of thirsty, urination, feces and specific symptoms which can be induced by dryness. And in the both unfavorable patterns the dark complexion on the faces is revealed. 3) 3rd step: The mild-severe patterns of the favorably exterior disease are differentiated in terms of the condition of fever, while the mild-severe patterns of the favorably interior disease are in differentiated based on whether abnormal symptoms are revealed in the gastrointestinal tract. Both of the unfavorably dangerous-urgent patterns in exterior and interior diseases are differentiated by the symptoms such as tinnitus, dim vision, weakness of legs and back pain, and lack of strength in legs and thighs.

• 한국생활과학회지
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• 제21권6호
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• pp.1199-1210
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• 2012

This study investigated the influence of obesity on depression and stress by analyzing the results of the national survey on health and nutrition. Relationships between normal, obese, and severely obese groups were investigated. The results of the study are as follows. First, obesity caused by demographic variables showed a relationship to both gender and average monthly income. In the case of the seriously obese group, females had higher rates of depression than males, and the high obesity group had lower average monthly income than the normal and obese groups. Second, obesity caused by health-related variables found that high blood pressure, hyperlipidemia, and diabetes that was not angina-related displayed higher rates of depression in the serious obesity group than in the other groups. As for subjective evaluations of one's own health condition, the serious obesity group showed a high tendency to evaluate their own health conditions negatively. Third, the difference between depression and stress related to obesity level showed no difference between the normal weight group and the obesity group; however, the seriously obese group demonstrated relatively higher occurrences of depression and higher stress scores. Fourth, the result for depression and stress level caused by demographic variables, health-related variables, and obesity demonstrated a direct relationship to gender, subjective level of satisfaction with one's personal finances, average monthly income, subjective perception of one's own health and severely obesity status. More specifically, it was found that the ratio of depression and stress score was higher when the subject was female, among those whose subjective evaluation of their own finances and health condition was negative, and those who suffered from severe obesity.

• Archives of Plastic Surgery
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• 제35권3호
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• pp.349-353
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• 2008

Purpose: There are 3 well-known surgical procedures to treat Pierre Robin sequence: tongue-lip adhesion, distraction osteogenesis of mandible, and tracheostomy. The classical tongue-lip adhesion is an effective way to keep airway. The tongue, however, becomes quite non-mobile and appears dormant until the patient could control upper airway and the adhesion can be maintained for prolonged period. Most of all, this procedure does not provide the correction of the micrognathia. Distraction osteogenesis is a good technique to correct micrognathia and to prevent tracheostomies in patients with Pierre Robin sequence. But airway keeping procedure is needed during the distraction period. The purpose of this study is to determine the usefulness of temporary tongue-lip traction during the initial period of mandibular distraction in Pierre Robin sequence patients with severe airway problems requiring operative procedure. Methods: It was a prospective study of 2 Pierre Robin sequence patients aged between 4 months and 6 months requiring surgical procedure to correct recurrent and severe pulmonary complications. Two patients underwent distraction osteogenesis of mandible. During the operation, deep one tension suture was performed to tract the tongue and lip. When the patient gained control of upper airway at the initial period of distraction and micrognathia was corrected, the traction suture was removed. Results: All patients were followed up. No patients complained severe pulmonary complications and tracheostomy could be avoided. No patients had severe pulmonary complication. The pulmonary condition of patients was good. Conclusion: In severe Pierre Robin sequence case, temporary tongue-lip traction is a good assistant method in distraction osteogenesis because this method can avoid tracheostomy.