• 대한기계학회논문집B
• /
• 제21권8호
• /
• pp.1056-1067
• /
• 1997

Present study visualized flow pattern and investigated spray characteristics of twin-fluid atomization with converging-diverging nozzles. Particle sizes were measured by using the Malvern particle analyzer, and the radial size distributions were evaluated by using the tomographic transform technique. The results show that the SMD generally increases in the radial direction at a prescribed liquid flow rate and the increasing rate in the SMD becomes gradual as atomizing gas pressure increases. The SMD decreases as the liquid flow rate increases at a fixed GLR (gas/liquid mass ratio). The atomization performance of the protrusion-type nozzle turned out to be superior to that of the flush-type. However, in the case of the protrusion-type, flow separation occurs outside the liquid delivery tube when the pressure at the gas nozzle chamber is high enough, which may deteriorate the atomization performance.

• 대한기계학회논문집B
• /
• 제27권6호
• /
• pp.781-788
• /
• 2003

In the present study, the heat and flow characteristics of a parallel-flow heat exchanger are numerically analyzed by using three-dimensional turbulent modeling. Heat transfer rate and pressure drop are evaluated using the concept of the efficiency index by varying the locations, the shapes and angles of inlet/outlet, and the protrusion height of flat tube. It is found that negative angle of the inlet improves the heat transfer rate and pressure drop. Results show that the locations of the inlet and outlet should be toward the right side and the left side to the reference model, respectively, in order to enhance the heat transfer rate and pressure drop. Increasing the height of the lower header causes pressure drop to decrease and yields the good flow characteristics. The lower protrusion height of flat tube shows the improvement of the heat transfer rate and pressure drop. The heat transfer rate is greatly affected by the parameters of outlet side such as the location and angle of the outlet. However, the pressure drop is influenced by the parameters of inlet side such as the location and angle of inlet and the height of the header.

• 복식문화연구
• /
• 제9권1호
• /
• pp.11-18
• /
• 2001

The purpose of this study is to survey women′s poor breast shapes depending on their ages and breast types, and thereupon, analyze the differences and correlations among them, and thereby, provide for some basic data useful to the development of the comfortable brassiere which can serve to correct the poor breast. 1. As a result of categorizing the types of schematic breast sides, "type 1" was characterized by medium lower part, greatest pro trusion of breast itself, volumed upper part and visible breast outside, while "type 2" be characterized by medium lower part, most flatness, poor upper part, smallest outside size and medium outside, and "type 3" was characterized by least poor lower part, medium protrusion of breast, poor upper part, medium outside size , and "type 4" was characterized by poorest lower part, medium protrusion of breast, poor upper part, medium outside size and poorest outside. 2. The breast locations could be categorized depending on brest side types; "type 1" a higher location of breast than the other types, "type 2"had a lower location of breast except for the nipples thant the other types, "type 3" had the lowest location of breast and "type 4" had a comparatively low location of breast but had the highest nipples.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권2호
• /
• pp.248-256
• /
• 1998

The effects of fuel injection system on the performance in a V8-type diesel engine was stuided in this paper. Fuel injection system is important factor which influence the engine performance and exhaust emission bcasuse the properties in the injected fuel depend on the atomization characteristics. In this study using diesel engine of 17.7:1 compression ration the engine performance and exhaust emission are measured experimentally according to 1000, 1400, 2200rpm in the full-load conditions. The chosen parameters for the major system are such diameter shape of combustion chamber and intake system. The results are as follows: As the nozzle hole diameter and injection angle become smaller and as the injection timing gets advanced the fuel consumption and concentration of smoke are decreasing whereas concentration of $NO_{x}$ is increasing. Andconcentration of $NO_{x}$ is increasing in accordance with the increase of injection pipe diameter and nozzle protrusion. Also it is shown that re-entrant type combustion chamber is more effective than that of toroidal type in the improvement of $NO_{x}$ reduction.

• 한국의류학회지
• /
• 제28권7호
• /
• pp.1019-1028
• /
• 2004

The purpose of this study was to compare the body measurements of cyclists and non-cyclists and to classify cyclists＇ body types to offer basic information for the bicycle apparel manufacturer in Korea. The anthropometric data was collected including both direct and indirect measurements of 81 cyclists (40 female, 41 male) aged from 19 to 24. Anthropometric measurements were analyzed using percentiles, T-test, factor and cluster analysis. The results were as follows; Comparison of anthropomeoic data between cyclist and non-cyclist was to clarify that cyclists have bigger size than non-cyclists; especially the thigh circumference shows big differences. As the result of factor analysis, 5 factors, which explain 74% of variance, were extracted from all items for male and female cyclists. The results of cluster analysis classified body types into 3 groups. Cluster 1 among three female cyclist groups has biggest torso and had an erect back. Cluster 2 has small size among three female group and drooping shoulders. Cluster 3 has the bended forward shoulders and shows the protrusion back. In case of male cyclists, cluster 1 has thin body type owing to big height measurements and small girth measurements. Cluster 2 among three male groups has the biggest torso and thigh circumference. Cluster 3 has big forward angle of shoulders and shows the protrusion of the back as female cyclist.

• 치과방사선
• /
• 제14권1호
• /
• pp.39-50
• /
• 1984

The aim of this study was to evaluate the dentofacial relationship of the Korean adult females who had excellent profile using roentgenocephalometry. The subjects were 35 females from 19 to 24 years of age selected among the professional models, beauty contest winners and performing stars. And, as the control group, 37 females from 18 to 23 years of age with normal occlusion and acceptable profile were selected. In both groups, each variable was measured and evaluated statistically introducing 24 reference points, 22 reference lines and 17 reference angles respectively. Conclusions from this study were as follows; 1. There was no significant difference between the two groups. But SNA and convexity angle which had indicated the maxillary protrusion were lesser in the professional models, beauty contest winners and performing stars than in ~he control group. 2. In the professional models, beauty contest winners and performing stars, the maxillary and mandibular incisors were more upright than in the control group. 3. The protrusion of the upper and lower lip was lesser in the professional models, beauty contest winners and performing stars than in the control group. 4. Professional models, beauty contest winners and performing stars revealed more straight profile than the control group and were similar to that of the Caucasian. 5. Generally, it was the tendency that the straight profile was accepted as esthetics.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제46권5호
• /
• pp.335-340
• /
• 2020

Objectives: This study sought to evaluate the efficacy of injecting botulinum toxin into the masseter and temporal muscles in patients with temporomandibular myofascial pain and sleep bruxism. Materials and Methods: The study was conducted based on a clinical record review of 44 patients (36 females and eight males; mean age, 35.70±12.66 years). Patients who underwent the injection of botulinum toxin into the masseter and temporal muscles for the management of temporomandibular myofascial pain and sleep bruxism were included in the study. Patients were diagnosed based on the Diagnostic Criteria for Temporomandibular Disorders. Sleep bruxism was diagnosed according to the criteria defined by the American Academy of Sleep Medicine. The values of the visual analogue scale (VAS) and range of jaw motion, including unassisted maximum mouth opening (MMO), protrusion, and right and left laterotrusion, were observed preoperatively and postoperatively at one-, three-, and six-month follow-up visits. Results: MMO, movements of the right and the left laterotrusion, and protrusion increased significantly (P<0.05), while VAS ratings decreased significantly at the three follow-up points relative to baseline values (P<0.05). Conclusion: Botulinum toxin is an effective treatment for patients with temporomandibular myofascial pain and sleep bruxism.

• 한국공작기계학회논문집
• /
• 제14권4호
• /
• pp.32-40
• /
• 2005

The purpose of this study is to investigate variation of spark plug protrusion and PDA valve on the exhaust emission in a gasoline engine. Swirl is one of the important parameters that affects the characteristics of combustion. PDA valve has been developed to satisfy requirements of sufficient swirl generation for improving the combustion and reducing of emission level. Also, especially, the variation of spark plug protrusion have an important effect to the early flame propagative process. This is largely due to the high flame speed by short of flame propagation distance. So, this is forced that injection timing, spark timing and intake air motion govern the stable combustion. As a result, using two combustion chamber, without charge of engine specification and the variable spark plug location and PDA valve could be reduced exhaust gas at a part load engine conditions(1500rpm imep 3.9bar, 2000rpm imep 3.2bar, 2400rpm imep 3.9bar).

• Archives of Plastic Surgery
• /
• 제34권4호
• /
• pp.535-537
• /
• 2007

Purpose: We experienced a patient with posttraumatic duplication of the sternoclavicular joint causing a protruding deformity, whose major complaint was aesthetic. The patients history, radiologic findings, and surgical treatment are reported. Methods: A 41-year-old bus driver complained a bony prominence at the left medial clavicle, which had developed after a fracture. The patient was annoyed by the protrusion, which was even visible, when he was wearing a pullover. A three dimensional CT scan showed that the medial head was split into two portions, of which the anterior portion was protruding. In general anesthesia the anterior portion of the medial head was excised. Results: The bony prominence was corrected successfully. Follow up three dimensional CT scans showed that the anterior cortex of the clavicle had regenerated completely at the resection line one year after the operation. Conclusion: Surgical interventions for complications after clavicular fracture are usually carried out, only if there is a limitation of function or if it is painful. We report of a patient with posttraumatic bifurcation of the medial clavicular head, most probably caused by malunion. Upon the patient's request, the deformity causing protrusion of the medial clavicular area was successfully resected for cosmetic reasons.

• Journal of Advanced Marine Engineering and Technology
• /
• 제29권4호
• /
• pp.443-452
• /
• 2005

The purpose of this study is experimentally to analyze the effects of intake port swirl, injection system and turbocharger on the engine performance and the emission characteristics in a V8 type turbocharger intercooler D.I. diesel engine of the displacement 16.7L, and to suggest the improvement of engine performance. Generally to enhance engine power, TCI diesel engine is put to practically use turbocharged intercooler in order to increase volume efficiency which is cooled boost air. As results of considering the factors of the intake port of swirl ratio 2.25, compression ratio 17.5. re-entrant $8.5^{\circ}$ combustion bowl, nozzle hole diameter ${\phi}0.33{\ast}3+{\phi}0.35{\ast}2$. nozzle protrusion 3.18mm, injection timing BTDC $12^{\circ}CA$ and turbocharger(compressor 0.6A/R+46Trim. turbine 1.0 A/R+57Trim) is the best in the full load in the engine performance and the exhaust characteristics of NOx concentration. Therefore. their factors are appropriated as intake system, injection and turbocharger system.