미세변화신증후군 환아에서의 각종 면역지표의 변화

박용훈,김정란,신정애 대한신장학회 1988 Kidney Research and Clinical Practice Vol.7 No.2

A prospective study was conducted to see the changes of various immunologic indices and its significance in minimal change nephrotic syndrome (MCNS). Study population consisted of 51 children with MCNS (7 infrequent relapser; IR, 38 frequent relapser steroid depen- dent; FR/SD and 6 partial responder; PR), in whom diagnosis was confirmed by percutaneous renal biopsy. Disease activity was divided into 3 stages; stage I- relapse period, stage II-within 30 days of remission and stage III-over 30 days of remission. The following results were obtained: Urinary N-acetyl-b-D-glucosaminidise (nM/min/mg- creatinine) showed elevated levels in stage I (72.7±60.3) and stage II (23.6±16.2) compared with stage III (6.8±4. 8) and control (4.0±+1.6). Urinary neopterin (mmol/mol creatinine) showed in- creased level in stage I (280+20) and stage II (198+22) compared with stage III (167±63) and control (170±36). The total T cell count (%) showed no changes between stages, nor between study group and control. However, T cell subset analysis showed T, cell count (%) lower in stage I (20.4±11.6). And stage II (20.1±7.6) compared with stage III (28.3 ±10.4). The T,/T, ratio was lower in stage I (0.64±0.41) and stage II (0.75± 0.56) compared with stage III (1.58± 1.08), and this lowering of T,/T, ratio was mainly caused by increase of T, cells. The total B cell count (%) showed no changes between stages, nor between study group and control. During relapse period, serum IgG was lower than control (344±248 versus 1.045±300 mg/dl). Serum IgE was also elevated in study patients compared with control (316±350 versus 49±37 mg/dl), and the elevation of IgE was more marked in FR/SD and PR group than IR group (67% versus 25%). In summary, it can be concluded from the present study that intimate relationship exists between MCNS and immune abnormality. The most pronounced changes has been noted in 8 subset and serum IgE, and marked elevation of serum IgM could be used as a predictor for frequent relapse or partial response in MCNS children.

자동차 1 천만대 시대

박용훈 대한지방행정공제회 1997 도시문제 Vol.32 No.341

Fabrication of Degradable Carboxymethyl Cellulose (CMC) Microneedle with Laser Writing and Replica Molding Process for Enhancement of Transdermal Drug Delivery

박용훈,하상근,최인욱,Kyu Sik Kim,박제량,최낙원,김범상,성종환 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

Transdermal drug delivery system (TDDS) may provide a more reliable method of drug delivery than oral delivery by avoiding gut absorption and first-pass metabolism, but needs a method for efficiently crossing the epidermal barrier. To enhance the delivery through the skin, we have developed a biocompatible, dissolvable microneedle array made from carboxymethyl cellulose (CMC). Using laser ablation for creating the mold greatly improved the efficiency and reduced the cost of microneedle fabrication. Mixing CMC with amylopectin (AP) enhanced the mechanical and tunable dissolution properties of the microneedle for controlled release of model compounds. Using the CMC microneedle array, we observed significant enhancement in the skin permeability of a fluorescent model compound, and also increase in the anti-oxidant activity of ascorbic acid after crossing the skin. Our dissolvable microneedle array provides a new and biocompatible method for delivery of drugs and cosmetic compounds through the skin.

클라이언트가 이동하는 환경에서 효율적인 연속 k-최근접 질의 처리를 위한 색인 구조

박용훈,서동민,윤종현,신재룡,최길성,유재수 한국정보과학회 2010 데이타베이스 연구 Vol.26 No.2

The interest of Location-Based Services (LBS) has highly increased according to the development of location aware techniques and mobile devices and also the researches on LBS have been progressed in recent years. In this paper, we propose ISR-tree (Incremental Search R-tree) which processes continuous k-NN queries efficiently in the environment composed of static objects and moving clients submitting queries. In ISR-tree, the leaf-nodes maintain the entries of their neighbor nodes and the entries help to find the neighbor leaf-nodes without visiting internal nodes when k-NN queries are processed. As a result, ISR-tree saves the cost to visit internal nodes. We prove the superiority of ISR-tree through the comparison with previous works. 최근 위치 인식 기술과 휴대 장치의 발달로 인해 이동하는 객체를 기반으로 하는 위치 기반 서비스(Location Based Service, LBS)의 관심이 점점 증가하고 있고 그에 관련된 연구들이 활발하게 진행되고 있다. 본 논문에서는 고정된 객체와 이동하는 질의 환경에서 연속 k-최근접 질의를 효율적으로 수행하는 색인구조인 ISR-tree(Incremental Search R-tree)를 제안한다. 이 구조는 단말 노드에서 이웃 노드들의 정보를유지하여 k-최근접 질의 처리시 중간 노드에 대한 탐색횟수를 감소시켰을 뿐만 아니라 연속 질의 처리를 위한질의 재수행시 중간 노드를 탐색하지 않는다. 제안하는 기법의 우수성을 평가하기 위해 R-tree와의 비교를수행하였다.

그리드 기반의 질의 색인을 통한 효율적인 연속 영역 질의 처리

박용훈,복경수,유재수,Park, Yong-Hun,Bok, Kyoung-Soo,Yoo, Jae-Soo 한국정보처리학회 2007 정보처리학회논문지D Vol.14 No.5

본 논문에서는 기존 그리드 기반의 질의 색인 기법을 변형하여 보다 적은 저장 공간을 사용하면서 보다 빠른 연산을 수행하는 연속 영역 질의 처리 기법을 제안한다. 제안하는 기법의 주요 특징은 두 가지 이다. 첫째, 각 질의에 비트 식별자를 부여하고 그리드의 각 셀은 이러한 비트 식별자의 조합으로 이루어진 비트 열을 이용하여 질의들의 겹침 정보를 반영한다. 이러한 비트 열을 통해 셀이 어떤 질의들에 포함되어져 있는지 빠르게 판단한 수 있으며, 두 셀 사이의 각 셀을 포함하는 질의 식별자들을 비교하지 않고 비트 열만을 비교하여 질의들의 포함관계를 알아내어 불필요한 연산을 줄일 수 있다. 둘째, 셀들을 그룹단위로 관리하여 불필요하게 비트 열의 길이가 증가하여 저장 공간을 낭비하고 비트 열의 비교 연산 시간이 증가하는 문제를 해결한다. 제안하는 기법이 기존 연속 영역 질의 처리 기법에 비해 우수함을 성능 평가를 통해 입증한다. In this paper, we propose an efficient continuous range query processing scheme using a modified grid based query indexing to reduce storage spaces and to accelerate processing time. The proposed method has two major features. First, each query has a bit identifier and each cell in a grid has a bit pattern that consists of the bit identifiers of the queries. The bit patterns present the relationship between cells and queries. Using the bit patterns, we can compute quickly what queries overlap a cell in a grid and reduce the number of unnecessary operations by comparing the bit patterns without comparing the query identifiers when we compute the relation between cells and queries. Second, the management of cells in the grid by groups prevents from wasting the storage space through the increase of the length of the bit pattern and increasing the comparison costs of bit patterns. We show through the performance evaluation that the proposed method outperforms the existing methods.

대중교통요금체계 개편 신중해야한다

박용훈,Park, Yong-Hun 대한교통학회 2004 교통 기술과 정책 Vol.1 No.1

권두언

박용훈 대한지방행정공제회 1997 도시문제 Vol.32 No.345

N/A

기업의 기술혁신활동에 관한 슘페터 가설 검정 : 국내 게임산업을 대상으로

박용훈,한현옥 한국산업경제학회 2019 산업경제연구 Vol.32 No.3

While empirical studies have been carried out to verify the Schumpeter hypothesis, there is a lack of research on innovation in the service industry in terms of quantity and diversity rather than manufacturing innovation studies. Therefore, this paper focused on the Korean game industry, which requires technological innovation in the service industry. This paper analyzed the structure and characteristics of Korean game industry based on technological regime and industrial organization theory. Also this paper analyzed the relationship between scale of firm, market structure and technology innovation activity in game industry using firms panel data. This study verifies the Schumpeter hypothesis. In particular, the empirical result of the structural differences among firms in the game industry shows that the relationship between scale of firm and technology innovation activity is heterogeneously the form of U-shaped and of inverted U-shaped simultaneously. According to the results, the Schumpeter hypothesis is rejected in the whole game industry. But in case of the developer of game industry, It has been shown that the Schumpeter hypothesis be supported by case of a few conglomerate. Therefore, as the game industry becomes more fragmented and diversified than the manufacturing industry, it needs support policy based on characteristics rather than the general scheme or support policy. 본 연구는 기술체제 및 산업조직 이론을 바탕으로 국내 게임산업의 구조 및 특징을 파악하고 게임산업에서 기업의 규모, 그리고 시장구조와 기술혁신활동 간의 관계를 기업별 패널 자료를 활용하여 실증분석 하였다. 특히, 기업의 규모 및 시장구조와 기술혁신활동에 대한 Schumpeter 가설을 검정하기 위해 POLS, RE 추정법을 이용하여 분석하였다. 게임산업 내 기업들이 가지는 구조적인 차이를 반영한 실증분석결과 기업규모와 기술혁신활동 간의 관계는 이질적으로 U자형 관계와 역 U자형 관계가 동시에 나타나는 것을 확인하였다. 이는 게임산업 전반에서는 Schumpeter 가설이 기각된다고 볼 수 있으며 개발사의 경우 소수의 규모가 큰 대기업에 대해 Schumpeter 가설이 일부 지지된다고 주장할 수 있을 것이다. 따라서 게임산업은 기존 제조업 보다 세분화되고 기업 전략이 다양화됨에 따라 일반적인 제도나 지원정책보다 기업특성을 반영한 지원정책이 필요할 것이다.

주차장이 도시교통에 미치는 영향

박용훈 대한지방행정공제회 1996 도시문제 Vol.31 No.330

Fabrication and characterization of dissolving microneedle arrays for improving skin permeability of cosmetic ingredients

박용훈,김규식,정민섭,성종환,김범상 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.39 No.-

Delivery of sufficient amounts of cosmetic ingredients through the skin is a big challenge in the cosmeticindustry, since the stratum corneum, the outer layer of the skin, acts as a barrier against externalsubstances. One of the methods to solve this problem is using microneedles. In this study, a laser-writingprocess is described for fabricating a polydimethylsiloxane mold for microneedles, which is a verysimple and efficient method compared to the conventional photolithography technique. Using thispolydimethylsiloxane mold, it was possible to fabricate a dissolving sodium hyaluronate microneedlearray with consistent shapes and sizes. Amylopectin was used to tailor the properties of themicroneedles, such as mechanical strength and solubility. When amylopectin content in the needleincreased, the mechanical strength of the needle increased but the dissolution rate of the microneedlesdecreased. Using the microneedle array, significant enhancement in the skin permeability ofniacinamide and the anti-oxidant activity of ascorbic acid after crossing the skin was observed. Theseresults indicate that the microneedle array developed in this study has the potential to be used incosmetics by being combined with conventional cosmetic patches.