북한산국립공원의 계류수질 보전 전략(I)

박재현,우보명,김우룡,안현철,조현서,추갑철,김춘식,최형태,Park, Jae-Hyeon,Woo, Bo-Myeong,Kim, Oue-Ryong,Ahn, Hyun-Chul,Cho, Hyun-Seo,Choo, Gab-Chul,Kim, Choon-Sig,Choi, Hyung-Tae 한국환경복원기술학회 2001 한국환경복원기술학회지 Vol.4 No.3

This study was conducted to investigate physicochemical property changes from July 1998 to August 2001 in Mt. Bukhansan National Park. Four water sampling points were selected to measure the quality of stream water in the northeastern part of the Mt. Bukhansan National Park. The results were summarized as follows; In spring, the average pH of stream water was below the first class of the river water quality standard, while it was normal level in summer. The average electrical conductivity was about 2.3~3.3 times higher in downstream water than in upstream water during spring and summer. The contents of anions($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$) were about 1.1~7.4 and 0.4~11.4 times higher in downstream than in upstream water, respectively. These results indicate that water quality was poorer in downstream than in upstream water. We suggest that stream water in the Mt. Bukhansan National Park should be protected from impacts of snow melting mineral particles in spring season and human impacts like wastewater of point source in summer season.

갑상선 절제 수술 후 Guardix-SG<SUP>Ⱂ</SUP>의 유착방지 효과

박재현,정종주,강상욱,남기현,장항석,정웅윤,박정수,Jae Hyun Park,M.D.,Jong Ju Jeong,M.D.,Sang Wook Kang,M.D.,Kee Hyun Nam,M.D.,Hang Seok Chang,M.D.,Woong Youn Chung,M.D. and Cheong Soo Park,M.D. 대한갑상선-내분비외과학회 2009 The Koreran journal of Endocrine Surgery Vol.9 No.3

Purpose: Postoperative adhesion of the surgical field seems to be troublesome not only to the patients, but also to the surgeons. Guardix-SG<SUP>Ⱂ</SUP> is a poloxamer/alginate mixture that reduced the incidence of postoperative adhesions when it is added to the abdominal surgery in animal models and also in clinical trials. This study was a randomized, prospective, double-blinded study to evaluate the antiadhesive efficacy and safety of Guardix-SG<SUP>Ⱂ</SUP> after total thyroidectomy. Methods: A total of 89 patients who underwent total thyroidectomy between July 2008 and February 2009 in Severance Hospital and Gang-Nam Severance Hospital were randomized to either the Guardix-SG<SUP>Ⱂ</SUP> treatment group (n=45) or the non-treatmentcontrol group (n=44). The patients were asked about their clinical symptoms (hypesthesia or paresthesia on the operative site (SN) and swallowing discomfort (SW)) by using a questionnaire, and the swallowing function was evaluated using Marshmallow Esophagography by one physician. The clinical symptoms and Marshmallow Esophagography were scored according to the results of assessment. The most severe state was scored as 0 and normal was scored as 3. Results: The scores of the clinical symptoms (SN and SW) were 2.67 and 2.49 in the treatment group, and 2.09 and 1.80 in the control group, respectively, at the postoperative 6th week (P=0.001, <0.001). The scores of the Marshmallow Esophagography were 2.93 in the treatment group and 2.73 in the control group (P=0.033). Abnormal findings were seen in 2 patients (4.4%) in the treatment group and in 10 patients (22.7%) in the control group (P=0.014). Conclusion: Guardix-SG<SUP>Ⱂ</SUP> seems to be effective in preventing adhesion after thyroidectomy. Further studies involving a larger number of subjects will be needed to make an application guideline. (Korean J Endocrine Surg 2009;9: 127-132)

홍수시 얕은기초의 세굴위험도 평가 사례연구

박재현,이주형,정문경,곽기석,Park. Jae-Hyun,Lee. Ju-Hyung,Chung. Moon-Kyung,Kwak. Ki-Seok 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

Scour vulnerability evaluation for shallow foundations was performed to assure bridge safety against scour in the national capital region. The case studies for 26 shallow foundations consisted of site investigation including boring test, bridge scour analysis for the design flood, bearing capacity evaluation of the bridge foundation before and after scour, and comprehensive evaluation of bridge scour vulnerability. Bridge scour vulnerability was determined based on the interdisciplinary concept considering predicted scour depth for the design floods and bearing capacity of foundation as well as dimensions of foundation. Nine of 26 shallow foundations showed the potential future vulnerability to scour with significant decrease in the bearing capacity of foundations due to scour and the remaining 17 were expected to maintain their stability against scour.

건설기업의 지식경영 수준 평가모델개발에 관한 연구

박재현,백종건,김재준,Park Jae-Hyun,Baik Jong-Keon,Kim Jae-Joon 한국건설관리학회 2002 한국건설관리학회 논문집 Vol.3 No.4

국내의 건설기업들은 건설시장의 개방 및 경쟁의 심화에 따라 국제 경쟁력의 강화 및 지속적인 경쟁우위를 점하기 위하여 지식경영을 도입하여 개인의 지식들을 조직의 역량강화에 노력하고 있다. 그에 따라 학문적 측면에서도 지식경영의 발전이 계속적으로 이루어져 왔으며 오늘날에는 지식경영을 도입한 기업들의 수준 평가나 성과에 많은 관심을 보이고 있다. 하지만 실제 연구에 있어서는 성과부분에 너무 치우쳐서 정확한 수준 평가 없이 성과에 대한 언급만을 하고 있는 실정이다. 따라서 본 연구는 건설기업으로 하여금 정확한 지식경영의 수준을 평가하여 지식경영의 여러 영역 중에서 좀더 관심을 기울여야 할 분야를 제시함으로써 지식경 영을 균형적으로 발전시킬 수 있는 건설기업의 지식경영 수준 평가모델을 제시하였다. Knowledge Management(KM), represented as a way to sustain or gain competitive edge in domestic construction companies since late 1990s economic fluctuation, whose priority is to transform individual tacit knowledge into explicit organizational one. Also, accompanied by academic researches, they come to turn their interests on KM leveling and its results. However, they went too far to KM results without commenting what their KM capabilities are and where they should lead. Thus, this research work suggests a leveling model for KM, especially construction company, whose role is to diagnose which parts they should be encouraged or how to strengthen their present capabilities.

Al₂O₃와 TiO₂의 반응소결로 제조한 Al₂TiO₅-기계가공성 세라믹스

박재현,이원재,김일수,Park, Jae-Hyun,Lee, Won-Jae,Kim, Il-Soo 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.6

Aluminium titanate($Al_2TiO_5$) has extremely anisotropic thermal expansion properties in single crystals, and polycrystalline material spontaneously microcracks in the cooling step after sintering process. These fine intergranular cracks limit the strength of the material, but provide an effective mechanism for absorbing strain energy during thermal shock and preventing catastrophic crack propagation. Furthermore, since machinable BN-ceramics used as an insulating substrate in current micro-electronic industry are very expensive, the development of new low-cost machinable substrate ceramics are consistently required. Therefore, cheap $Al_2TiO_5$-machinable ceramics was studied for the replacement of BN ceramics. $Al_2O_3-Al_2TiO_5$ ceramic composite was fabricated via in-situ reaction sintering. $Al_2O_3$ and $TiO_2$ powders were mixed with various mol-ratio and sintered at 1400 to $1600^{\circ}C$ for 1 h. Density, hardness and strength of sintered ceramics were systematically measured. Phase analysis and microstructures were observed by XRD and SEM, respectively. Machinability of each specimens was tested by micro-hole machining. The results of research showed that the $Al_2TiO_5$-composites could be used for low-cost machinable ceramics.

백운산 지역에서 계류수의 이화학적 성질에 미치는 양어장의 영향(II)

박재현,우보명,김우룡,안현철,Park, Jae-Hyeon,Woo, Bo-Myeong,Kim, Oue-Ryong,Ahn, Hyun-Chul 한국환경복원기술학회 2001 한국환경복원기술학회지 Vol.4 No.1

Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around Mt. Paekun area were monitored seasonally and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality were observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases in physicochemical indices such as the amount of dissolved oxygen, percentage of dissolved oxygen, total amount of cation, total amount of anion and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design should be incorporated to large scale fish farm development plan in forested watershed area.

수평형 HRSG의 탈질설비에서 암모니아 분사위치 변동에 따른 암모니아 유량비교

박재현,유호선,Park, Jae-Hyun,Yoo, Hoseon 한국플랜트학회 2018 플랜트 저널 Vol.14 No.4

발전설비에서의 질소산화물 배출 규제치가 강화됨에 따라 1990년대에 설치된 HRSG도 탈질설비를 추가로 설치해야 하는 상황이 되었다. 그러나 HRSG 내부에 촉매와 암모니아 분사장치 모두를 설치할 수 있는 공간이 없기 때문에 그 대안으로써 HRSG 내부에는 촉매만 설치하고 암모니아 분사장치는 가스터빈 배기덕트로 변동하여 설치하는 것을 검토하였다. 본 연구에서는 인천복합발전소를 대상으로, 암모니아 분사장치를 HRSG 중압 과열기 후단과 가스터빈 배기덕트에 설치하여 암모니아를 분사였을 때 대기 배출기준 8.5 ppm을 만족하는 암모니아 소비량을 각각 측정하였다. 연구결과 가스터빈 배기덕트 암모니아 분사방식이 HRSG 중압 과열기 후단 분사방식에 비해 소비량이 1.2배 정도 증가한 것으로 나타났다. 따라서 HRSG 수명 30년 운영을 고려한다면 HRSG 내부에 암모니아 분사장치를 설치할 수 없는 경우 가스터빈 배기덕트에 암모니아 분사장치를 설치하는 것이 추천된다. As the emission limits for NOx in power generation facilities were strengthened, HRSGs installed in the 1990s became necessary to install additional DeNOx system. However, since there is no space in the HRSG for installing the entire the catalyst and ammonia injection grid, as an alternative, the catalyst was installed inside of the HRSG and the ammonia injection device was installed in the exhaust duct of the gas turbine. Experiments were conducted in horizontal HRSG of Incheon combined cycle power plant. Experimental results show that the ammonia injection method in the gas turbine exhaust duct is 1.2 times higher than the HRSG internal ammonia injection method. However when operating a HRSG for 30 years as its life span, ammonia injection method in the gas turbine exhaust duct is more economical than the cost of new HRSG construction.

폴리머를 이용한 CIS(CMOS Image Sensor) 디바이스용 웨이퍼 레벨 접합의 warpage와 신뢰성

박재현,구영모,김은경,김구성,Park, Jae-Hyun,Koo, Young-Mo,Kim, Eun-Kyung,Kim, Gu-Sung 한국마이크로전자및패키징학회 2009 마이크로전자 및 패키징학회지 Vol.16 No.1

본 논문에서는 웨이퍼 레벨 기술을 이용한 CIS용 폴리머 접합 기술을 연구하고 접합 후의 warpage 분석과 개별 패키지의 신뢰성 테스트를 수행하였다. 균일한 접합 높이를 유지하기 위하여 glass 웨이퍼 상에 dam을 형성하고 접합용 폴리머 층을 patterning하여 Si과 glass 웨이퍼의 접합 테스트를 수행하였다. Si 웨이퍼의 접합온도, 접합 압력 그리고 접합 층이 낮을수록 warpage 결과가 감소하였으며 접합시간과 승온 시간이 짧을수록 warpage 결과가 증가하는 것을 확인하였다. 접합 된 웨이퍼를 dicing 하여 각 개별 칩 단위로 TC, HTC, Humidity soak의 신뢰성 테스트를 수행하였으며 warpage 결과가 패키지의 신뢰성 결과에 미치는 영향은 미비한 것으로 확인되었다. In this paper, the polymer adhesive bonding technology using wafer-level technology was investigated and warpage results were analyzed. Si and glass wafer was bonded after adhesive polymer layer and dam pattern for uniform state was patterned on glass wafer. In this study, warpage result decreased as the low of bonding temperature of Si wafer, bonding pressure and height of adhesive bonding layer. The availability of adhesive polymer bonding was confirmed by TC, HTC, Humidity soak test after dicing. The result is that defect has not found without reference to warpage.

당뇨병 환자에서 관절경적 회전근 개 봉합술 후 발생한 화농성 견관절염의 치료 - 증례 보고 -

박재현,최원기,김세식,최창혁,Park, Jae-Hyun,Choi, Won-Ki,Kim, Se-Sik,Choi, Chang-Hyuk 대한관절경학회 2009 대한관절경학회지 Vol.13 No.1

당뇨환자로서 관절경적 회전근 개 봉합술을 시행 후 견관절의 화농성 관절염으로 진단된 2예에 대해 관절경적 치료 및 추가적인 개방성 치료를 시행하였다. 관절경적 회전근 개 봉합술 후 감염은 평균 18일 뒤에 발생하였으며, 증상 발현으로부터 수술까지의 평균 기간은 65일이었다. 또한 기능 평가는 KSS, ASES, UCLA, Constant 점수를 이용하였다. 관절경적 변연 절제술과 추가적인 시술 후 평균 22.5일의 항생제 치료로 4개월에 염증이 치료되었으며 최종 결과는 KSS점수가 82점, UCLA점수가 33점, ASES점수가 91점, Constant점수가 71점이었다. 관절경적 회전근 개 봉합술 후 발생한 화농성 견 관절염은 관절경적 치료 및 추가적인 시술로 치료되었고, 관절 운동 범위 및 기능적 결과와 통증 및 만족도는 많이 개선되었다. Two diabetes mellitus patients treated by arthroscopy and associated procedure for an infection after arthroscopic rotator cuff repair were involved. The time interval from rotator cuff repair to symptom development was 18 days in average and arthroscopic debridement and associated procedure for infection applied in average 65 days after symptom development. Patient evaluation was done according to the KSS, ASES, UCLA and Constant Score. We used antibiotics for average 22.5 days after arthroscopic debridement and associated procedure, the infection was treated in average 4 months. At final follow-up, the mean KSS score was 82 points, the mean UCLA score was 33 points, the mean ASES score was 91 points, the mean Constant score was 71 points. All infections following arthroscopic rotator cuff repair were cured by arthroscopy and associated procedure. ROM and functional results were much improved, the pain and satisfaction were also much improved.

작업자의 작업공구에 따른 근골격계 질환과 작업효율 모델

박재현,김경훈,김재준,Park, Jae-Hyun,Kim, Kyong-Hoon,Kim, Jae-Jun 대한건축학회 2011 대한건축학회논문집 Vol.27 No.2

Due to a massive outbreak in the workplace and a rapid increase of industrial disaster victims, musculoskeletal disorders is recently emerging as a major issue in the field of industry safety and health. Musculoskeletal disorders has already held a high rank of occupational diseases in advanced countries and it is rapidly growing every year in Korea. In particular, it is expected that people working in the construction industry have higher rates of musculoskeletal disorders given that the construction industry requires a higher level of dependence on human labor and laborers' high intensity of physical labor outside. In this regard, targeting laborers involving in building construction, this study attempts to analyze the impact of musculoskeletal disorders which can be shown according to working hand tools, making to model musculoskeletal disorders on efficiency. As a result of analyses, it appears that there are differences in body parts that hurt skeleton and musculature between structural steel laborers and carpenters owing to different working hand tools they use. In case of structural steel laborers, they tend to feel most psychological distress when their necks and shoulders are under stress. In contrast, carpenter is likely to be agitated when their legs and knees are exposed to stress. Accordingly, this study is worthwhile by finding out different levels of musculoskeletal stress and different body parts depending on the tools laborers use, in turn proving that this has an impact on efficiency through modeling and quantifying it.