• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.8
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• pp.627-635
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• 2012

This study aims at developing an artificial neural network(ANN)-based predictive and adaptive temperature control method to control the openings at internal and external skins, and heating systems used in a building with double skin envelope. Based on the predicted indoor temperature, the control logic determined opening conditions of air inlets and outlets, and the operation of the heating systems. The optimization process of the initial ANN model was conducted to determine the optimal structure and learning methods followed by the performance tests by the comparison with the actual data measured from the existing double skin envelope. The analysis proved the prediction accuracy and the adaptability of the ANN model in terms of Root Mean Square and Mean Square Errors. The analysis results implied that the proposed ANN-based temperature control logic had potentials to be applied for the temperature control in the double skin envelope buildings.

• Toxicological Research
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• v.28 no.1
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• pp.51-56
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• 2012

A novel synthetic hexapeptide (SFKLRY-$NH_2$) that displays angiogenic activity has been identified by positional scanning of a synthetic peptide combinatorial library (PS-SPCL). This study was carried out to investigate the irritation of the SFKLRY-$NH_2$ on the skin. The tests were performed on the basis of Korea Food and Drug Administration (KFDA) guidelines. In results, cell toxicity is not appeared for SFKLRY-$NH_2$ in HaCaT cells and B16F10 cells. SFKLRY-$NH_2$ induced no skin irritation at low concentration ($10{\mu}m$), mild irritation at high concentration (10mM). We consider that this result is helpful for saying about the safety of SFKLRY-$NH_2$ in clinical use.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.14 no.2
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• pp.35-38
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• 2001

Dermatitis herpetiformis (DH) is a chronic disease of the skin marked by groups of watery, itch blisters. It is characterized by urticarial plaques and blisters on the elbows, buttocks, and knees, although other sites may also be involved. The ingestion of gluten (the proteins gliadin and prolamin contained in wheat, rye, oats, and barley) triggers an immune system reponse that deposits a substance, IgA (immonuglobin A), under the top layer of skin. IgA is present in affected as well as unaffected skin. DH is a hereditary autoimmune disease linked with celiac disease. Treatment for DH is twofold. (1) Remove the cause: gluten. (2) Suppress the skin response with drugs such as Dapsone or some other sulphones. The latter is the most common treatment used as it is rapidly relieves the itch. However there are some side effects associated with these medications and they need to be taken under medical monitoring with blood tests to detect side effects. Recently, we experienced a DH and that was successfully treated by the herbal medication and external therapy. The medications taken by the patient were yongdamsagantanggami and external therapy were gosam and gumunhwa. So we report this case with a bief review of the oriental medical and medical literatures.

• Geomechanics and Engineering
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• v.27 no.6
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• pp.595-604
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• 2021

With the advantages of high permeability and strength, pervious concrete piles can be suitable for ground improvement with high water content and low bearing capacity. By comparing the strength and permeability of pervious concrete with different aggregate sizes (3-5 mm and 4-6 mm) and porosities (20%, 25%, 30% and 35%), the recommended aggregate size (3-5 mm) and porosity (30%) can be achieved. The model tests of the pervious concrete piles in soft soil (silt and clay) foundations were conducted to evaluate the bearing characteristics, results show that, for the higher consolidation efficiency of the silty foundation, the bearing capacity of the silty foundation is 16% higher, and the pile-soil stress ratio is smaller. But when it is the ultimate load for the piles, they will penetrate into the underlying layer, which reduces the pile-soil stress ratios. With higher skin friction of the pile in the silty foundation, the pile penetration is smaller, so the decrease of the pile axial force can be less. For the difference in consolidation efficiency, the skin friction of pile in silt is more affected by the effective stress of soil, while the skin friction of pile in clay is more affected by the lateral stress. When the load reaches 4400 N, the skin friction of the pile in the silty foundation is about 35% higher than that of the clay foundation.

• Steel and Composite Structures
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• v.45 no.3
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• pp.467-482
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• 2022

One of the major failure modes in composite sandwich structures is the separation between skins and core. In this study, the effect of employing foam filled composite corrugated core on the skin/core debonding (resistance to separation between skin and core) is investigated both experimentally and numerically. To this aim, triangular corrugated core specimens are manufactured and compared with reference specimens only made of PVC foam core in terms of skin/core debonding under bending loading. The corrugated composite laminates are fabricated using the hand layup method. Also, the Vacuumed Infusion Process (VIP) is employed to join the skins to the core with greater quality. Utilizing an End Notched Shear (ENS) fixture, three point bending tests are performed on the manufactured sandwich composite panels. The results reveal that the resistance to separation capacity and flexural stiffness of sandwich composite has been increased about 170% and 76%, respectively by using a triangular corrugated core. The Cohesive Zone Model (CZM) with appropriate cohesive law in ABAQUS finite element software is used to model the progressive face/core interfaces debonding the difference between experimental and numerical results in predicting the maximum born load before the skin/core separation is about 6 % in simple core specimens and 3% in triangular corrugated core specimens.

• Toxicological Research
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• v.21 no.1
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• pp.15-21
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• 2005

There is now a growing concern about the possible toxicity of heavy metals in cosmetics. Heavy metals can be used as cosmetic ingredients or may be present as low level impurities in some of the raw materials. Chromium derivatives are used as pigments in cosmetics. Chromium is essential and toxic trace elements. Chromium may cause skin allergy. However, the regulations related to cosmetic products give no limit values for Chromium. Hexavalent chromium is significantly more toxic than trivalent chromium. Hexavalent chromium may present a carcinogenic risk at high concentrations. Therefore, it is important to consider oxidation state of chromium when analyze chromium. The purpose of this study is to determine the concentrations of water-soluble trivalent and hexavalent chromium in samples of makeup products, and to assess the safety of cosmetics on the basis of animal sensitization tests using guinea pig. The present study of chromium in 48 makeup products of 12 manufacturers provides a basis for assessing safety of makeup products. Water-soluble hexavalent chromium was not detected in any product. Water-soluble trivalent chromium was detected in only 9 eye shadows out of 48 makeup products, and could not be quantified 3 out of 9 eye shadows. The highest level of water-soluble trivalent chromium was about 10 mg/kg in spite of 90,000 mg/kg of total chromium. The results of animal sensitization tests show that 200 mg/kg of trivalent chromium and 5 mg/kg of hexavalent chromium have no harmful effect. No cross-reaction among these metals was found. Accordingly, the concentrations of water-soluble chromium in makeup products seemed to be safe. The overall results indicate that chromium in cosmetics probably have no significant toxicological effects. However, It is necessary to set guidelines on the maximum permissible concentration of water-soluble chromium in cosmetics.

• Journal of agricultural medicine and community health
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• v.40 no.4
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• pp.240-249
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• 2015

Objectives: Farmers are known to be exposed to a variety of allergens related to the work environment. This study was conducted to determine the sensitization rates as well as South Korea that they are sensitized to certain allergens farmers through the skin prick test. Methods: By targeting a total of 1143 people living in the rural town of Gyeonggi Province, it was conducted a questionnaire containing demographic and occupational risk factors and underwent skin prick tests with 15 types of allergens(including positive and negative controls). Multivariable logistic regression analysis was used to analyze the association between occupational risk factors and skin prick test positivity. Results: Except for the 30 people whose result is invalid, positive rate of the skin prick test was 18.6% in 1,113 people. The species of house dust mite, Dermatophagoides pteronyssinus and Dermatophagoides farinae was the highest at 8.7% and 8.6%. After adjusted by age, gender, smoking and education level, odds ratio of flower plant farmers is 4.467(95% CI: 2.094-9.527) and fruit farmer is 2.275(95% CI: 1.096-4.721). In addition, the rate of sensitization to grass pollen mixture of the flower plant farmers is significantly higher(15.9%, p<0.001) than other allergens. Conclusions: Even farmers, the rate of sensitization to allergens related to the general environment, such as house dust mite is relatively dominant. However, given the presence of potential cross-reactivity between the allergens or distribution showed that the unique aspects of allergen sensitization in the flower growers, occupational cause is not be completely ruled out.

• Geotechnical Engineering
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• v.14 no.5
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• pp.163-172
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• 1998

To study the carrying capacity behavior of pile, dynamic pile testis and static load tests were carried out on two instrumented piles during and some time after pile driving. Cone Penetration Test( CPT) and Standard Penetration Test(SPT) were also performed at the test site before pile tests to investigate the relationship between unit skin friction of piles and cone tip resistance values and SPT N values. Total static capacity of pile reached the ultimate stage at the pile head settlement of about 0.055D (D : Pile diameter), at which skin friction of Pile already Passed the maximum value, but the end bearing was still increasing with the pile head settlement. The carrying capacity of pile increased in the form of natural logarithmic function with the time after pile driving. The increase in skin friction with time was very substantial the increase in skin friction 40 days after pile driving was 4.6 times of that determined during pile driving. The contribution of skin friction to the total capacity twas insignificant in the beginning, but became substantial 40 days after pile driving. This implies that the tested pile initially responded as an end bearing pile and later behaved as a friction pile. It was also noted that unit skin friction of pile might be ielated to cone tip resistance values(q.) and SPT N values, though the coefficient of this relationship might differ from one soil group to another and was somewhat greater than the value used in the design practice of Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.487-497
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• 2020

The study examined the effects, strength, and weakness of chemical peeling and physical peeling, which are some types of peelings that are commonly used for cosmetic skin management for women. For this study, of which the study period was from November 1 to December 27, 2011, 20 female subjects with the compound skin type were investigated. Ten women were assigned to the chemical peeling group, and the other 10 were assigned to the physical peeling group. The experiment continued for six weeks, with one test session per week, totaling six tests. During each session, a skin measurement instrument was used to measure the oil, keratin, pore, wrinkles, and pigments. The results of the tests showed that, in the case of chemical peeling, both glycolic acid peeling and lactic acid peeling were effective in preserving the skin moisture. With physical peelings, crystal peeling was more effective on wrinkles, while diamond peeling was more effective in keratin and pigment improvement. A comparison of the peeling with different media revealed physical peelings to have more effect on more items, but chemical peeling was more effective in moisture and oil changes.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.9
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• pp.110-118
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• 2007

ISB (Inner structured and bonded) panel with a pyramidal inner structure is actively developing to reduce the weight and to improve the crashworthiness of the material. The objective of this paper is to investigate into the variation of impact characteristics of ISB panels with a pyramidal inner structure according to joining types between skin sheets and inner structures. Several drop impact tests have been performed. In order to examine the impact characteristics at a drawing condition, drawing type of experimental set-up has been proposed. From the results of the experiments, the influence of joining types between skin sheets and the inner structures on the characteristics of the deformation, the energy absorption and the failure has been quantitatively examined. In addition, it has been shown that maximum load decreased and the maximum displacement increases as the joining type changes from the bonding to the welding. The results of the observation of the specimen have been shown that major wrinkles form in the minor crimping direction irrespective of the joining types. Through the comparison of the experimental results for bonding and welding specimens, it has been shown that the absorption energy of the bonded specimen is nearly 1.3-1.5 times of the welded specimen at the same displacement.