• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.335-338
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• 1996

We attempted to reconstruct basement membrane (BM) in between the epidermal compartment and dermal compartment in the artificial skin preparation and examine its effect on the skin architecture as well as on the epidermal differentiation. Laminin, one of the component of BM, stimulate the migration of the basal cells but type IV collagen which is a major component of the mechanical network of BM did not stimulate epidermal migration. However laminin in the presence of type IV collagen at a 1:1 molar ratio did not stimulate epidermal migration but provide nice demarcation between epidermis and dermis. This mixture of laminin and type IV collagen enhanced epidermal differentiation in the artificial skin based on the morphological observation as well as biochemical criteria. The epidermal acquirement of migratory ability on the laminin-rich substrate suggest that this type of unbalance in the expression of the components of BM may prevail in the area of healing tissue and the invasive transition of the tumor. The result in this study provide the technical improvement in the artificial skin preparation and further application of this technique for the reconstruction of other bio-artificial organ.

• 대한화장품학회지
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• 제23권3호
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• pp.48-74
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• 1997

Retinlyl Palmitate, the skin normalizerm is useful to promote greater skin elasticity, to diminish lipid peroxidation and skin roughness following UV exposure, and promote a youthfulgeneral skin appearance. In manufacturing creams, Retinyl Palmitate, which is a derivative of retinol, is used since reionol is easily oxidized by heat and light. However, only a small mount of retinol, is used since using a large amount of it may be harmful to its stability. In this study, thermal stability and UV stability of W/O-, W/S-, O/W-, and MLV-type creams containing 5% of retinyl palmitate and 10% of tocopheryl acetate are measured by Chroma Meters, and the content of RP is quantitatively analyzed by HPLC at 25 $^{\circ}C$ and 45 $^{\circ}C$. Also, how RP has been changed by heat, light, etc. is measured by HPLC, and toxicity of the changed substance is studied. Particle size of each type of the cream if measured, cellular renewal is measured by using DHP and Chroma Meters in order to study their efficacy and effect, moisture content is measured by using Corneometer and Tewameter, and how much wrinkles are improved is studied by using Image Analyzer. Development of MLV-type cream containing 5% of RP and 10% of TA, and satisfying conditions for better creams has been successful.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.59-63
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• 2005

Compression tests were performed for six types of hat stiffened composite panels with different bonding methods and stiffener section shapes. Six panels showed similar behaviors in buckling and post-buckling region before a skin-stiffener separation failure occurred. The skin-stiffener separation failures occurred in the panels with closed type stiffeners regardless of bonding methods, but not in the panels with open type stiffeners. The separation failures not only reduced the postbuckling strength but also changed buckling mode and postbuckling stiffness. All the separation failures were initiated at the stiffener flange edges closest to skin buckling crests. The co-cured or secondary bonded panels with open type stiffeners had the largest structural performance. Because the post-buckling strength and performance of the composite stiffened panels are reduced by the separation failure, it is important to find bonding methods, stiffener types and manufacturing parameters for preventing of the separation failure.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권12호
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• pp.550-557
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• 2006

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper is proposed two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value(MAV) circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• 대한화장품학회지
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• 제22권1호
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• pp.40-59
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• 1996

Retinol은 열과 빛에 쉽게 산화되기 때문에 그 유도체인 Retinyl Palmitate를 사용하고 있으나 이것 또한 안정성이 우려되어 많은 양을 사용하지 못하고 있다. 본 연구에서는 Retinyl Palmitate 5% 와 Tocopgeryl Acetate 10%를 함유한 W/O, W/S, O/W, MLV Type의 크림에서 열적 안정성 및 UV 안정성을 CHROMA METERS로 측정하였으며, $25^{\circ}C$, $45^{\circ}C$에서 RP의 함량을 HPLC로 정량 분석하였다. 또한 RP가 열, 빛 등에 의해서 어떤 물질로 변화하였는지를 측정하였으며, 변화된 물질의 독성에 대한 연구를 하였다. 각각의 크림 TYPE 마다 입자 SIZE를 측정했으며, DNA와 CHROMA METERS를 사용하여 CELLULAR RENEWAL을 측정하였다.

• Archives of Plastic Surgery
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• 제33권3호
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• pp.269-275
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• 2006

This study is to provide details of the unique anatomical features on the alar lobule region in Korean nose. We hypothesized that the anatomy of this area differs according to the shape of the alar lobule. Based on the prominence and roundness of alar lobules, they were classified into horizontal and vertical types. A total of 20 fresh cadaver noses(10 for each type) were dissected. The anatomical differences between the horizontal and vertical types were investigated by gross and histologic studies. The alar lobule is composed of three layers, i.e., external skin, muscle, and vestibular skin. Profound differences between the two alar lobule types were evident in terms of the volume of the dilator naris anterior muscle, the insertion of the dilator naris posterior muscle, and the thickness of the external skin at the lateral end of the alar circumference. The horizontal type has a greater volume of dilator naris anterior muscle, an additional insertion of the dilator naris posterior muscle, and thicker external skin at the lateral end of the alar circumference than the vertical type. The Korean nose differs anatomically and morphologically from the Caucasian nose. This study shows that there are anatomic differences between the horizontal and vertical types of alar lobules in Korean nose.

• 대한두개안면성형외과학회지
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• 제19권1호
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• pp.79-82
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• 2018

Formation of an ideally-shaped tragus remains one of the most challenging issues during staged tragus reconstruction in microtia patients. The authors describe a new method used to treat a unique case of concha-type microtia in which the 10-year-old male patient had only a portion of pre-existing cartilage at the tragus site. An anomalous skin lump was also present. During the initial stages of the reconstruction, the two-stage Nagata method was used for surgical correction of the microtia. An autologous rib cartilage graft was used to form the ear framework. A temporoparietal fascia flap was also constructed. Remnant skin tags and anomalous cartilage that accompany microtia are usually removed during microtia repair. However, the cartilage and skin lump were preserved during the reconstruction. The skin lump was later used to form a vascularized chondrocutaneous island flap that supplemented the portion of cartilage during tragus formation. The result was a new tragus that was satisfactorily improved in both size and shape. Patients with concha-type microtia may benefit from the use of this new method for tragus formation.

• 유통과학연구
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• 제18권10호
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• pp.65-75
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• 2020

Purpose: This study aims to examine how to review contents of experiential and utilitarian products (e.g., skincare products) and how to affect review helpfulness by applying natural language processing techniques. Research design, data, and methodology: This study uses 69,633 online reviews generated for the products registered at Amazon.com by 13 Korean cosmetic firms. The authors identify key topics that emerge about consumers' use of skincare products such as skin type and skin trouble, by applying bigram analysis. The review content variables are included in the review helpfulness model, including other important determinants. Results: The estimation results support the positive effect of review extremity and content on the helpfulness. In particular, the reviewer's skin type information was recognized as highly useful when presented together as a basis for high-rated reviews. Moreover, the content related to skin issues positively affects review helpfulness. Conclusions: The positive relationship between extreme reviews and helpfulness of reviews challenges the findings from prior literature. This result implies that an in-depth study of the effect of product types on review helpfulness is needed. Furthermore, a positive effect of review content on helpfulness suggests that applying big data analytics can provide meaningful customer insights in the online retail industry.

• KSBB Journal
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• 제29권1호
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• pp.42-49
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• 2014

The aim of this study was to develop a composite human skin equivalent for wound healing. Collagen type1 and acellular dermal matrix powder were utilized as the scaffold with dermal fibroblasts and keratinocytes for the development of a composite human skin equivalent. Fibroblast maintained the volume of composite skin equivalent and also induced keratinocytes to attach and proliferate on the surface of composite skin equivalent. The composite human skin equivalent had a structure and curvature similar to those of real skin. Balb-C nu/nu mice were used for the evaluation of full-thickness wound healing effect of the composite human skin equivalent. Graft of composite skin equivalent on full-thickness wound promoted re-epithelialization and granulation tissue formation at 9 days. Given the average wound-healing time (14 days), the wound in the developed composite skin equivalent healed quickly. The overall results indicated that this three-dimensional composite human skin equivalent can be used to effectively enhance wound healing.

• 한국화재소방학회논문지
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• 제31권1호
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• pp.98-107
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• 2017

본 논문은 피난 안전성 평가를 통해 이중외피 구조가 적용된 건축물에서의 피난 성능 개선방안을 제시하고자 한다. 이중외피 구조가 적용된 건축물은 화재 발생시 굴뚝효과로 인한 상층 연소확대 현상이 빠르고 그 특성이 각 구조별로 다른 특성을 갖고 있으며 설계 및 제도적 기준 또한 미비하여 일반 건축물에 비해 피난 안전성을 확보하기 어렵다. 따라서 본 논문에서는 10층의 단일 피난계단이 적용된 이중외피 건축물로 가상의 모델링을 구성하였으며, 피난 성능을 개선하기 위한 방안으로 피난 완료시점을 옥외로의 탈출까지로 변경하고, 각 구조별 위험도를 고려한 경보방식을 제안하였다. 그 결과 기존의 경보방식과 비교하여 박스형은 약 26.4%, 복도형은 약 29.1%, 샤프트-박스형은 약 23.4%, 전면형은 약 26.3%의 피난 성능이 개선되었고, 전층의 재실자의 안전을 확보 할 수 있었다.