• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.1
• /
• pp.666-671
• /
• 2018

A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.6 no.4
• /
• pp.327-343
• /
• 2004

During tunnel construction, ground failures often occur due to existence of weak zones, such as faults, joints, and cavities, ahead of tunnel face. It is hard to detect effectively weak zones, which can lead underground structure to fail after excavation and before supporting, by using conventional characterization methods. In this study, an enhanced analytical method of predicting weak zones ahead of tunnel face is developed to overcome some problems in the conventional geophysical exploration methods. The analytical method is based on Coulomb's and Gauss' laws with considering the characteristics of electric fields subjected to rock mass. Using the developed method, closed form solutions are obtained to detect a spherical shaped zone and an oriented fault ahead of tunnel face respectively. The analytical results suggest that the presence of weak zones and their sizes, location, and states can be accurately predicted by combining a proper inversion process with resistance measured from several electrodes on the tunnel face. It appears that the skin depth or resistivity in rock mass is affected by the diameter of tunnel face, natural electric potential and noises induced by experimental measurement and spatial distribution of uncertain properties. The developed analytical solution is verified through experimental tests. About 1800 concrete blocks of 5cm by 5cm by 5cm in size are prepared and used to model a joint rock mass around tunnel face. Weak zones are simulated ahead of tunnel face with a material which has relatively higher conductivity than concrete blocks. Experimental results on the model test show a good agreement with analytical results.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.23
• /
• pp.10451-10456
• /
• 2015

Background: We defined melanoma distribution in a large series of Turkish patients and evaluated the prognostic parameters of melanomas. Materials and Methods: A total of 1574 patients' data was retrospectively collected at 18 centers in Turkey. Demographic characteristics were questioned and noted. Prognostic parametres were evaluated based on sentinel lymph node involvement. Results: Mean age was 56.7 (4-99) years. While 844 (53.6%) cases were male, 730 (46.4%) cases were female. One thousand four hundred forty-seven (92%) cases were invasive melanoma and 127 (8%) cases were in-situ melanoma. The most common histopathological form was the superficial spreading melanoma (SSM) which was found in 549 patients (37.9%). It was followed by nodular melanoma in 379 (26.2%), acral lentiginous melanoma (ALM) in 191 (13.2%) and lentigo maligna melanoma in 132 (9.1%), respectively. On univariate analysis, lymphovascular invasion (p<0.001), tumor thickness (p<0.001), histopathological subtype (p<0.001), Clark level (p=0.001), ulceration (p<0.001), ${\geq}6/mm^2$ mitosis (p=0.005), satellite formation (p=0.001) and gender (p=0.03) were found to be associated with sentinel lymph node positivity. Regression was associated with sentinel lymph node negativity (p=0.017). According to multivariate analysis, lymphovascular invasion and tumor thickness were significant independent predictive factors of SLN positivity. Patient age, tumor localization, precursor lesions, lymphocytic infiltration and neurotropism were not related with sentinel lymph node involvement. Conclusions: In this retrospective analysis, it was found that the prevalence of SSM is at a lower rate while the prevalence of ALM is at a higher rate when compared to western countries. According to Breslow index; most of the melanoma lesions' thickness were greater than 2 mm, corresponding Clark IV. Vascular invasion and tumor thickness are the most important factors for sentinel lymph node involvement.

• Journal of fish pathology
• /
• v.14 no.2
• /
• pp.71-80
• /
• 2001

The purpose of this study was to investigate the microbiological characteristics and the distributions of the bacteria causing streptococcicosis occurred in marine fish farm, Korea. Many kinds of cultures fishes suffered from the disease accompanied with typical symptoms, including darkening of the skin, exophthalmia, petechiae inside of the opercula and distended abdomen. The isolates from the diseased fishes were compared with Lactococcus garvieae by biochmical, biophysical and serological methods and polymerase chain reaction(PCR) assay. We isolated 35 strains of the geuns Streptococcus from the diseased olive flounder, Paralichthys olivaceus, yellow tail, Seriola quinqueradiata and Korean rockfish, Sebastes schlegeli. 15 strains out of the isolates were identified to L. garvieae and the others were not because of their different biochemical and biophysical charateristics. Seven strains of the isolates were agglutinated by rabbit serum raised against L. garvieae $KG^+$ phenotypic cells(ATCC49156)as a reference strain. Twenty-one strains of the isolates identified to L. garvieae since they were formed the expected band through performing PCR assay using specific primers, pLG-1(5'-CATAACAATGAGATCGC-3') and pLG-2(5'-GCACCCCGCGGTTG-3'). In the present study, it showed that L. garvieae was a dominant strain causing streptococcicosis in the tested area due to occurrence of 21 strains as L. garvieae out of all the isolates, 9 atrains as Streptococcus sp. and 5 strains as Enterococcus sp.

• Journal of fish pathology
• /
• v.5 no.2
• /
• pp.135-142
• /
• 1992

The absorption and excretion times of oxolinic acid(OX) used in farms as new aquatic antibiotics commonly were evaluated with determination of the effects of water temperature and feeding to parameters by using the bioassay technique. On the same time, antibacterial activity and the complex formation of oxolinic acid with serum proteins of two different fishes were compared to those oxytetracycline(OTC). With more than 10 times lower MIC values than those of OTC in the strains among 13 analyzed fish pathogens. OX did not show the decresed antibacterial activity by the binding of serum proteins in carp and tilapia. It implies more powerful potential of OX as aquatic medicine OTC. The serum concentration of OX after different administrations the oral, i.m., i.v and dipping methods were compared. The higher beginning concentration in serum and faster excretion times were obserbed in i.m. and dipping methods respectively. In the oral and i.m. administration, peak serum concentration after 24－48 hrs and slow excretion times demonstrated in both methods. These pharmacokinetic characteristics similar at $30^{\circ}C$ and $20^{\circ}C$ water temperature conditions, however, beginning serum concentration of OX in fish dipped in $50mg/\ell$ sol after starvation for 2 wks was appeared lower than those of fed fish. It suggests the importance of biological condition of the gill or skin for absorption of antibiotics after dipping administration.

• Journal of Environmental Health Sciences
• /
• v.43 no.3
• /
• pp.167-175
• /
• 2017

Objectives: Children may be more exposed to certain environmental contaminants because they react with greater sensitivity and have different food intakes and breathing rate per unit of body weight compared to adults. The aim of this study was to determine general exposure factors such as skin surface area, period and frequency of exposure, and others among Korean children aged ${\leq}18$ years old. This study was carried out as the first of its kind in Korea. Methods: We developed 23 recommended exposure factors for Korean children aged 0 to 18 years by reclassifying raw data from the National Health and Nutrition Examination Survey and the National Statistical Information Service, as well as through investigation by experiments in the absence of related data. Results: Reflecting the activity patterns of about 9,000 children, the daily inhalation rates for long-term exposure ranged from $9.49m^3/day$ for children from birth to <2 years to $14.98m^3/day$ for children aged 16 to <18 years. The research found that Korean children spent an average of 22.21 hours indoors, 0.67 hours outdoors, and 1.12 hours in-transit every day. Young children (${\leq}2$ years old) spent approximately 34 more minutes outdoors on weekends than they did on weekdays. Conclusion: Various physiological variables in the human body reflect characteristics of children that can directly influence risk exposure. Therefore, the identification of general exposure factors based on Korean children is required for appropriate risk assessment.

• The Korean Journal of Ecology
• /
• v.28 no.3
• /
• pp.129-134
• /
• 2005

The monthly variations of physico-chemical and microbiological water quality were investigate in the artificial Lake Geumgang near estuary barrage. Sixty heterotrophic bacteria were isolated and identified by amplification and sequencing of 16S rDNA. Water temperature, pH, and inorganic nutrients($NH_4$-N, $NO_2$-N, $NO_3$-N, $PO_4$-P) were measured. Concentrations of DO, BOD, and inorganic nutrients were lower than in the middle-stream of Geum river The population densities of heterotrophic bacteria and total coliforms varied from $4.1{\pm}1.0\times10^2$ to $6.7{\pm}1.1{\times}10^3\;cfu\;ml^{-1}$, and 0 to $2.3{\pm}0.6{\times}10^2\;cfu\;ml^{-1}$, respectively. Among the measured numbers of physiological groups of bacteria, cellulolytic bacteria showed higher population densities than those of other physiological groups. Bacterial community structure was analysed based on 16S rDNA partial sequencing. Among 60 isolates, dominant genus was Pseudomones (20 strains).

• Korean Journal of Occupational Health Nursing
• /
• v.9 no.1
• /
• pp.5-17
• /
• 2000

The occupational health nursing guideline for primary care was developed by the Korean Academic Society of occupational health nursing and the organization for occupational health nurses (currently known as the Korean Association of Occupational Health Nurses) in 1993. Since then, there have been many changes in the health care environment and job performance of occupational health nurses. Appropriate revisions are necessary of the guidelinea based on this background. The purpose of this study was to describe the use of the occupational health nursing guideline for primary care and to analyze the characteristics of primary care activities by occupational health nurses. The questionnaire was mailed to 150 occupational health nurses(OHNs) with the response rate of 64%. The results can be summarized as follows; 1. 65.6% of OHNs have been using the guideline for primary care and 75.9% of them agreed that the guideline was be helpful for their job. 2. Common symptom care, emergency care and chronic illness care were more frequently implemented than occupational disease care by OHNs. In manufacturing industries, emergency care was more frequently implemented than chronic illness care in contrast to the service industries. 3. Most frequent common symptoms treated by OHNs were indigestion, diarrhea, abdominal pain, headache, and coughing. In the case of chronic illness, OHNs more frequently treated diseases of the gastro-intestinal system, skin and sensory organs, and the respiratory system. Emergency care for bruises, burn, and abrasions was more frequently provided. VDT syndrome was the most common occupational disease cared by OHNs in manufacturing and service industries. 4. OHNs prescribed the medicine for external application more frequently than internal medicine. Remedy for colds, analgesics, vitamins, and digestives were more frequently used. From these results, we suggest that the guideline should be revised to emphasize the activities consisting problem finding such as health assessment, physical examinations, monitoring and screening, and to renew the drug list in the range of over- the counter medication (OTC). In the future, the guideline will include the strategies for the role as the case manager.

• Archives of Craniofacial Surgery
• /
• v.21 no.4
• /
• pp.229-236
• /
• 2020

Background: Oncologic resection of the scalp confers several obstacles to the reconstructive surgeon dependent upon patient-specific and wound-specific factors. We aim to describe our experiences with various reconstructive methods, and delineate risk factors for coverage failure and complications in the setting of scalp reconstruction. Methods: A retrospective chart review was conducted, examining patients who underwent resection of fungating scalp tumors with subsequent soft-tissue reconstruction from 2003 to 2019. Patient demographics, wound and oncologic characteristics, treatment modalities, and outcomes were recorded and analyzed. Results: A total of 189 patients were appropriate for inclusion, undergoing a range of reconstructive methods from skin grafting to free flaps. Thirty-three patients (17.5%) underwent preoperative radiation. In all, 48 patients (25.4%) suffered wound site complications, 25 (13.2%) underwent reoperation, and 47 (24.9%) suffered from mortality. Preoperative radiation therapy was an independent risk factor for wound complications (odds ratio [OR], 2.85; 95% confidence interval [CI], 1.1-7.3; p=0.028) and reoperations (OR, 4.45; 95% CI, 1.5-13.2; p=0.007). Similarly, the presence of an underlying titanium mesh was an independent predictor of wound complications (OR, 2.49; 95% CI, 1.1-5.6; p=0.029) and reoperations (OR, 3.40; 95% CI, 1.2-9.7; p=0.020). Both immunosuppressed status (OR, 2.88; 95% CI, 1.2-7.1; p=0.021) and preoperative radiation therapy (OR, 3.34; 95% CI, 1.2-9.7; p=0.022) were risk factors for mortality. Conclusion: Both preoperative radiation and the presence of underlying titanium mesh are independent risk factors for wound site complications and increased reoperation rates following oncologic resection and reconstruction of the scalp. Additionally, preoperative radiation, along with an immunosuppressed state, may predict patient mortality following scalp resection and reconstruction.

• Research in Community and Public Health Nursing
• /
• v.1 no.1
• /
• pp.582-594
• /
• 1989

The purpose of this study is to analyze the factors affecting the school health teachers' self-confidence. This study was conducted with 87 school health teachers working in Jeonbuk province, from September to December, 1986, The results are follows; 1. Demographic characteristics of school health teachers 1) Age mean ; 34, range; 23-54 2) School Nursing experience mean; 11 years, range; 0-24 3) Clinical experience mean; 1.5 years, range: 0-13 2. Status of school health resources & nursing activities 1) Personnel resource school health teacher: pupils : 1 : 1,436 'classes=1:31 'general teacher=1:39 2) Budget Total school operating budget: School health budget : 100 : 4.2 (52.2 thousand Won) Half of the school health budget expend on medicine. 3) Clinic 80% of all schools have health clinic seperately. 71.32 of all schools have less than $35m^2$, 23.9%, $36-66m^2$. 4) Only 20% of all schools have organization for health 5) Average of clinic visitor for 1 year; 2,084 Major problem is on digestive system. And other problem: respiratory, skin, musculo - skeletal system, dental problem, etc... 6) Literal message for 1 year; 12 times. For health education (4), vaccination (3), examination of parasites (2), etc... 3. The degrees of the school health teachers' self-confidence 1) Program planning & evaluation; 2.9. 2) Clinic management; 2.8 3) Health education; 2.8 4) Management of school environment; 2.7 5) Health care services; 2.5. 6) Operating of school health organization; 2.3 4. Significances to self-confidence on school health nursing activities 1) Program planning & evaluation: home message (r=.228, p<.05) No. of clinic visitor (r=.220, p<.05) expending time for clinic management (r=.229, p<.05) religion (t: 2.5, p<.05) level of school (F=6.3, p<.005) 2) Clinic management: age of school health teacher (r=-.202, p<.05) school health experience (r=-.211, p<.05) salary step (r=.187, p<.05) expending time for clinic management (r=.315, p<0.1) marital status (t=3.97, p<.005) level of school (F=3,139, p<0.5) 3) Management of school environment: level of school (F=3.899, p<.05) expending time for clinic management (r=-,216, p<0.5) 4) Health care service: age of school health teacher (r=-.186, p<.05) marital status (t= 3.67, pH.005) 5) Health education: expending times for clinic management (r=-.252, p<05) level of school (F=5.343, p<.01) 6) Operating of health organization; age of school health teacher (r=-.258, p<.01)salary step (r=.188, p<.05) Based on the above results, the suggestions are as follows; 1. Need to raise ,appointment rate school health teacher. 2. Need to raise self-confidence on school health nursing activities through the inservice education or re-inforcement. 3. Need to secure adequate budget for school health. 4. Participation of school health teacher and support of school master for school health services are required. 5. Need for use the health clinic seperately, adequate facilities and free utilization by visitors.