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.

일본(日本)에서 한류변(漢流邊)의 환경부원(環境復元) 발전전략(發展戰略)(I)

박재현,우보명,이헌호,Park, Jae-Hyeon,Woo, Bo-Myeong,Lee, Heon-Ho 한국환경복원기술학회 2000 한국환경복원기술학회지 Vol.3 No.1

This study was carried out to introduce current status and development strategy for an environmental restoration of stream side in Japan, and to consider a methodology which could be effectively applied for the environmental restoration of stream side in Korea. Since the end of 20th century, the native ecology and landscape of Japan remained only a limited areas such as stream side, water side and forest areas. Therefore, recently the works of forest conservation and erosion control of environmental restoration on stream side tended to increased. The strategic prospects of environmental restoration in Japan were summarized as follows : 1. From the ecological point of view, we have to develop a certain method and technology in construction of forest conservation and erosion control to prevent environmental problem from erosion control works. 2. We have to restore not only a continuity of stream side forest from a primitive area to an estuary but also the stream side forest to preserve and restore a stream side vegetation on a primitive watershed areas. 3. We have to improve a method of construction or removal of a structure which were constructed in the stream to restore a water side environment and an interaction system for an integration on a forest land, stream, and erosion control. Additionally, we have to establish an integrated evaluation method and an enforcement system after investigation of influences on natural environment, stream, and forest etc. 4. We have to conduct an integrated research to investigate the ecosystem of stream side, and construct environmentally friendly water park and erosion control park which considered natural environment and its landscape. Additionally, we need to introduce and adopt a natural style stream construction method to restore a water side areas.

지리산국립공원내 칠선계곡 탐방로의 회복에 관한 분석

박재현 ( Jae Hyeon Park ) 한국환경보건기술학회(구 한국환경복원녹화기술학회) 2010 한국환경복원기술학회지 Vol.13 No.2

To investigate the restoration procedure on soil physical properties at the surface of visiting road affected by rest-year system. This study was carried out at visiting roads of stream of Chilsun in Jirisan. Mean soil strength in 20cm of soil depth was lower in the Rest-Year System areas (1.5-1.9 times in Site 2, 1.1-7.5 times in Site 3) than in the control (Site 1). Soil strength was recovered by the Rest-Year System in the national park. Mesopore rate (pF 2.7) in 0-15 cm of soil depth was higher in the Rest-Year System areas (1.2 times) than in the control. This indicates that mesopore rate is rapidly restoring in the Rest-Year System areas. Pore space rate in 0-7.5 cm of soil depth was higher in the Rest-Year System areas (23.2% in Site 2, 23.6% in Site 3) than in the control (22.4% in Site 1). Pore space rate in 7.5-15 cm of soil depth was also higher in the Rest-Year System areas (22.9% in Site 2 and Site 3) than in the control (18.9% in Site 1). Soil pore space was remediable by the Rest-Year System. Bulk density in 0-7.5 cm of soil depth was lower in the Rest-Year System areas (1.674g/cm3 in Site 2, 1.668g/cm3 in Site 3) than in the control (1.723g/cm3 in Site 1). Bulk density in 7.5-15 cm of soil depth was lower in the Rest-Year System areas (1.785g/cm3 in Site 2 and 1.721g/cm3 in Site 3) than in the control (1.721g/cm3 in Site 1). Soil bulk density was decreased in the Rest-Year System areas of the national park. Amount of soil erosion was lower in the Rest-Year System areas (0.017m3/km/yr in site 2, 0.023m3/km/yr in site 3) than in the control (0.054m3/km/yr in site 1).

북한산국립공원 북동사면에서 동결융해침식 및 토사유출이 계류수질에 미치는 영향

박재현(Jae Hyeon Park) 한국산림과학회 2001 한국산림과학회지 Vol.90 No.4

This study was conducted to investigate influences of solifluction and sediment runoff on the stream water qualities during the spring season. The study sites were four points in the northeastern area of the Bukhansan National Park. And, field surveys were carried out in the spring of 1999, 2000 and 2001. The results of this study were summarized as follows; During the investigation period, the amounts of sediment caused by solifluction on stream side slopes in the downstream were 1.3∼1.7 times as large as those in the upstream. The pH of sediment caused by solifluction was a potential influence on the pH of stream water. Amounts of dissolved Cl^-, NO₃^- and SO₄^(2-) in stream water were proportion to the average amounts of Cl^-, NO₃^- and SO₄^(2-) in the sediment caused by solifluction. In the spring, the average pH of stream water was lower than the first class of the river water quality standard because of increasing chemical concentration as well as the contents of anions(Cl^-, NO₃^- and SO₄^(2-)) in the spring season. Also, the average electrical conductivity of water in downstream was about 2.3-3.3 times higher than that in upstream. The amounts of anions(Cl^-, NO₃^- and SO₄^(2-)) of water in downstream were about 1.2∼7.4, 1.1∼3.9, 1.1∼1.4 times higher than those in upstream, respectively. Therefore, these results showed that the water quality of downstream was worse than that of upstream. As a result of regression analyses, the linear and exponential equation of pH and water quantity was pH = 1.7926 × stream water quantity + 5.9577(R² = 0.46), and those of electrical conductivity and water quantity was EC = 34.417e^(3.6334 × stream water quantity(m/sec) (R² = 0.44).

생명이 살아 숨쉬는 친환경적 하천관리

박재현,Park, Jae-Hyeon 한국하천협회 2009 하천과 문화 Vol.5 No.2

산림유역내 강수로부터 계류수질에 미치는 영향인자 분석 - pH , 용존산소 , 전기전도도 -

박재현,우보명 ( Jae Hyeon Park,Bo Myeong Woo ) 한국산림과학회 1997 한국산림과학회지 Vol.86 No.4

This research was conducted to analyze the influence of the environmental factors on water quality such as pH, dissolved oxygen, and electrical conductivity of rainfall, throughfall, soil water(A and B layer), and stream water quality at a small forested watershed. Rainfall, throughfall, soil water(A and B layer), and stream water were sampled at the study sites in Kwanak Arboretum, Seoul National University in Mt. Kwanak for 14 months(Jul. 1, 1996∼Aug. 31, 1997). Average rainfall pH value was 6.06(ranged from 5.02 to 6.60). Acid rain frequency(less than pH 5.6) was 16.7% . The lowest rainfall pH value was 5.02. Average of pH values in hydrological processes were decreasing in the following order, stream water $gt; soil water [Prunus serrulata var, spontanea (B layer$gt;A layer)] $gt;throughfall(Prunus serrulata var. spontanea)$gt;soil water [Carpinus laxiflora(B layer $gt; A layer)]$gt; throughfall(Carpinus laxiflora) $gt; rainfall $gt; soil water [Pinus rigida(B layer $gt; A layer)] $gt;throughfall(Pinus rigida). pH values of throughfall in Prunes serrulata var. spontanea and Carpinus laxaflora were higher in Pines rigida. Average of dissolved oxygen values in hydrological processes were decreasing in the order, stream water $gt;throughfall(Carpinus laxiflora$gt; Prunus serrulata var, spontanea$gt; Pines rigida) $gt; rainfall $gt; soil water [Prunes serrulata var. spontanea(A layer) $gt; Pines rigida(A layer) $gt; Carpinus laxiflora(A layer) $gt; Prunes serrulata var. spontanea(B layer) $gt; Pines rigida(B layer)$gt; Carpinus laxiflora(B layer)]. And average electrical conductivity values in hydrological processes were decreasing in the order, soil water (B layer $gt; A layer) $gt; throughfall(Pinus rigida $gt; Prunes serrulata var, spontanea $gt; Carpinus laxiflora) $gt; stream water $gt; rainfall. Multiple regression equations of electrical conductivity and Mg^(2+), Na^+, total amount of cation, total amount of ion, and no. of before non-rain days in rainfall, throughfall, soil and stream water shows high significance(Multi R; 0.84).

802.11 Ad-Hoc 네트웍에서 Power Save Mechanism을 개선한 DAPSM 알고리즘

박재현,이장수,김성천,Park, Jae-Hyun,Lee, Jang-Su,Kim, Sung-Chun 한국정보처리학회 2007 정보처리학회논문지 C : 정보통신,정보보안 Vol.14 No.6

최근 무선 네트워킹 장치들이 등장 하면서 제한된 배터리에 의존하는 무선 호스트들의 전력 절감은 중요한 이슈 가 되었다. 특히 Ad-Hoc에서 배터리는 제한된 에너지를 제공하기 때문에 무선 호스트에 의해서 소모되어지는 에너지의 양을 감소시키기 위한 기술은 대단히 중요하다. 특히 MAC 과 라우팅 에서 전력 절감을 이루기 위한 논문들이 기존에 발표 되었다. 이 논문에서는 IEEE 802.11 표준의 DCF(Distributed Coordination Function)에서의 전력 절감 메카니즘을 향상 시킨 논문 이다. DCF를 위한 IEEE 802.11 전력 절감 메카니즘에서는 비콘 간격 이라는 시간으로 나누어지며 또한 이러한 각각의 비콘 간격이 시작될 때 각각의 노드들은 ATIM 창 동안 깨어 있어야 한다. 물론 모든 노드는 같은 시간에 깨어 있기 위해서는 동기화 되는 것이 필요하다. ATIM 창 동안 노드들은 비콘 기간 동안 깨어 있는 상태로 있을 것인지를 결정하기 위해서 control packet을 교환 한다. 이러한 ATIM 창 크기는 각각의 노드들의 전력 절감에 상당한 영향을 미친다. 따라서 이 논문은 ATIM 창 크기를 동적으로 증감시켜서 보다 에너지 효율을 발휘 하고자 하는 논문이다. Recently, wireless networking devices that depend on the limited Battery and power-saving of wireless hosts became important issue. Batteries can provide a finite amount of energy, therefore, to increase battery lifetime, it is important to design techniques to reduce energy consumption by wireless hosts. This paper improved power saying mechanism in Distributed Coordination Function(DCF) of IEEE 802.11. In the IEEE 802.11 power saving mechanism specified for DCF, time is divided into so-called beacon intervals. At the start of each beacon interval, each node in the power saving mode periodically wakes up during duration called the ATIM Window. The nodes are required to be synchronized to ensure that all nodes wake up at the same time. During the ATIM window, the nodes exchange control packets to determine whether they need to stay awake for the rest of the beacon interval. The size of the ATIM window has considerably affected power-saving. This paper can provide more power-saving than IEEE 802.11 power saving mode because ATIM window size is efficiently increased or decreased.

초장대 교량, 그 기술적 한계를 넘어 초장대 교량사업의 의미 및 지반기술의 중요성

박재현,정문경,전경수,송필용,Park, Jae-Hyeon,Jeong, Mun-Gyeong,Jeon, Gyeong-Su,Song, Pil-Yong 한국지반공학회 2011 지반 : 한국지반공학회지 Vol.27 No.1

Homocysteine과 혈중(血中) 지질농도(脂質濃度)와의 상관성(相關性) 연구(硏究)

박재현,황우준,조남근,김성철,고영철,Park, Jae-Hyun,Hwang, Woo-Jun,Cho, Nam-Geun,Kim, Sung-Chul,Ko, Young-Chul 대한한방내과학회 2006 大韓韓方內科學會誌 Vol.27 No.3

Object : This study was carried out to investigate the correlation between homocysteine and serum lipids which are known risk factors of stroke. Methods : The subjects were a total of 60 patients divided into a control group (n =30) and a sample group (n =30). The control group was normal homocysteine level without clinical symptoms, and the sample group was high homocysteine level with headache, dizziness, hypertension and so on. clinical symptoms, Each group was measured and compared for serum homocysteine, total cholesterol, triglyceride(TG), low density lipoprotein(LDL), and high density lipoprotein(HDL). Results : Total cholesterol, TG, and LDL were significantly increased and HDL was significantly decreased in the sample group. which was a high homocysteine level group compared with the control group, which was a normal homocysteine level group. Conclusion : In these results. it was suggested that increase of homocysteine leads to increase of serum total cholesterol, TG, LDL, but causes decrease of HDL. It seemed that risk of stroke is more at high homocysteine level than normal.

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.