북한강 수계의 남조 Anabaena 대발생과 강우의 관계

변정환 ( Jeong Hwan Byun ),조인환 ( In Hwan Cho ),황순진 ( Soon Jin Hwang ),박명환 ( Myung Hwan Park ),변명섭 ( Myeong Seop Byeon ),김백호 ( Baik Ho Kim ) 한국하천호수학회 2014 생태와 환경 Vol.47 No.2

To evaluate the relationship between dynamics of Cyanobacterial bloom and rainfalls, a monthly monitoring of water quality and phytoplankton from the three serial lakes (Lake Ui-am, Lake Chung-pyeong and Lake Pal-dang) in the North Han River System were examined 12 times from May 2012 to March 2013. A dense bloom of cyanobacterium Anabaena spp., was occurred over three lakes in the summer season of 2012. In Lake Ui-am, the Anabaena population appeared in June, showed a peak in July (43,850 cells mL-1) and disappeared in November 2012. In Lake Chung-pyeong and Lake Pal-dang, Anabaena population commonly appeared in July, showed the peaks (31,648 cells mL-1 and 7,136 cells mL-1, respectively) in August, and entirely disappeared in September 2012. Over the three lakes, the phytoplankton community was commonly dominated by diatoms before Monsoon, cyanobacteria during Monsoon, and diatoms after Monsoon, respectively, indicating a Monsoon-dependent succession. A correlation analysis revealed that dynamics of Anabaena population was strongly related with rainfall (r=0.72, r=0.83, r=0.88, P.0.01 for three lakes), and partly with nutrients, inflow and outflow of lakes. Therefore, this study indicates that the outbreak and destruction of Anabaena bloom in North Han River System between 2012 and 2013 was impacted by rainfalls. However, a high density of cyanobacteria in Lake Ui-am remained after Monsoon, and thus, may produce bad-order and toxins from phytoplankton.

북한강 수계에 출현한 남조류와 이취미의 상관관계

변정환 ( Jeong Hwan Byun ),황순진 ( Soon Jin Hwang ),김백호 ( Baik Ho Kim ),박진락 ( Jin Rak Park ),이재관 ( Jae Kwan Lee ),임병진 ( Byung Jin Lim ) 한국하천호수학회(구 한국육수학회) 2015 생태와 환경 Vol.48 No.4

To evaluate the relationship between dynamics of cyanobacteria and odorous compounds, a monthly monitoring of water quality and phytoplankton were conducted at the three serial lakes (Lake Ui-am, Lake Cheong-pyeong and Lake Pal-dang) in the North Han River for 11 times from May 2014 to March 2015. In the three serial lakes, phytoplankton communities showed that seasonal changes in Bacillariophyceae- Cyanophyceae-Bacillariophyceae. Anabaena and Pseudanabaena were dominant species in August and September 2014. At the same time the odors (Geosmin, 2-MIB) were also detected with high concentration. Relationship between environmental factors and cyanobacterial abundance showed a significant correlation with Anabaena circinalis and geosmin (r=0.983, p<0.01). In the case of Pseudanabaena limnetica showed a signi- ficant correlation of total nitrogen (r=0.685, p<0.01) and NO3-N (r=0.723, p<0.01). In addition, similarly Pseudanabaena limnetica and 2-MIB (r=0.717, p<0.01) was high. The odorous compounds appeared in the North Han River water were considered to be a direct relationship with cyanobacteria.

암호화폐공개(ICO) 투자 참여의도 영향요인 분석

변정환(Jung-Hwan Byun),성행남(Haengnam Sung),정대을(Dae-Yul Jeong) 한국인터넷전자상거래학회 2021 인터넷전자상거래연구 Vol.21 No.5

ICO(Initial Coin Offering) based on Blockchain technology is in the spotlight as a method of investing funds for early start-ups. ICO is an investment method like as Angel Investment or Venture Capital, but it has unique characteristics that are different from other investment methods because it raises fund from the people who have enough fund, but most of them are not specialist in investment. This study analyzes the intention of investment and influencing factors in ICO. The theoretical model was built based on TAM(Technology Acceptance Model). To test, hypotheses, measurement model and structural model was verified with a survey of 187 samples who are potential investors to ICO. The research model was enough to find influence factors to ICO investment intention with the samples. The structural model showed the strong relationship among the perception of easy to use, usefulness, attitude, and intention to invest on ICO, but the quality of investment information about the offering company did not affect the usefulness of ICO. Concludingly, traditional TAM approach is enough to find influence factors on ICO investment intention like another technology based services.

창업 투자 모금을 위한 ICO(Initial Coin Offering)의 수용도에 대한 집단간 차이 분석

변정환(Jung Hwan Byun),성행남(Haengnam Sung),정대율(Dae Yul Jeong) 한국창업학회 2021 한국창업학회지 Vol.16 No.5

본 연구의 목적은 창업기업의 초기 투자 모금 방법 중의 하나인 ICO(Initial Coin Offering)에 대해 일반투자자 집단의 특성에 따라 그 수용도에 차이가 있는가를 분석하기 위한 것이다. ICO는 암호화 기술을 이용한 토큰 발행을 통해 초기 창업기업의 투자자금을 조달하는 방식으로 투자 위험도가 매우 높은 반면, 법적인 제약이 적어 투자에 성공 시에 큰 수익을 얻을 수 있어 점차 혁신적인 창업기업의 자금조달 수단으로 자리를 잡아가고 있다. 본 연구에서는 기술기반의 ICO 투자 수용도에 있어 투자자 집단들 간에 차이가 있을 것으로 가정하고 잠재적일 투자자들을 대상으로 실증연구를 실시하였다. 연구 방법은 설문조사를 통해 일반투자자의 특성과 ICO 수용에 대한 자료를 수집하고, 카이제곱 분석을 통해 집단 간 차이분석을 실시하였다. 차이분석결과, 성별, 투자성향에 따라 유의적인 차이를 보였으나, 투자 경험은 그 종류에 따라 달리 나타났다. 본 연구는 일반투자자들도 블록체인과 같은 정보기술을 기반으로 하는 ICO가 창업기업의 새로운 투자수단으로 인식되고 있으며, 투자자의 특성에 따라 큰 차이가 있음을 검증하였다는데 그 의의가 있지만, 기존 선행 연구자료가 부족하고 ICO의 이용자가 국내에는 아직 극소수이기 때문에 일반화하기 어렵다는 한계점이 있다. 그럼에도 불구하고, 본 연구의 결과는 새로운 정보기술기반의 투자수단이나 투자플랫폼 개발과 ICO 투자대상자의 선정을 위한 타겟 마케팅 략수립에 유용한 정보를 줄 것으로 사료된다. The purpose of this study is to analyze the characteristics of general investors and technology acceptance factors for ICO, which is the initial stage investment method of blockchain-related startup companies. In this study, an empirical study was conducted on potential investors, assuming that there would be differences between investor groups in the technology acceptance in ICO. The research data on characteristics of general investors and ICO acceptance were collected through a survey, and differences between groups were analyzed through chi-square analysis. This paper verified that there were significant differences according to gender and investment propensity, but investment experience differed according to the investment types. This study is meaningful in that ICOs based on block chains are recognized as a new investment method for startups by general investors. In addition, the research results will provide useful information for the development of new information technology-based investment methods or investment platforms. As well, this paper will contribute to develope target marketing strategies for the selection of ICO investors.

기술수용모델을 이용한 창업기업의 신규코인상장(ICO) 참여의사 분석

변정환(Jung-Hwan Byun),정대율(Dae-Youl Jeong) 한국창업학회 2018 한국창업학회 Conferences Vol.2018 No.2

본 연구는 창업기업의 신규코인상장(ICO) 참여에 대한 의사결정 요인에 대해 분석 한다. ICO는 암호화폐에 대한 폭발적 관심과 함께 블록체인 기술을 이용한 응용분야 로 크라우드펀딩과 같이 창업기업 초반에 온라인 플랫폼을 통해 불특정 다수를 대상 으로 투자자를 모집한다. 현재, 한국을 비롯한 중국 등 ICO를 금지하고 있는 국가도 있는 반면에 ICO를 새로운 사업분야로 육성하기 위한 스위스나 싱가포르 같이 적극 적으로 유치하고 장려하는 국가도 있다. 연구를 위한 첫 번째 단계로 ICO의 개념을 정의하고 창업기업의 자금조달 방법인 크라우드펀딩과 IPO간의 비교를 통해 유사점 을 찾는다. 그리고 ICO의 기업 참여수와 모금금액에 대한 통계자료와 함께 국가별 ICO 및 사업분류별 조사자료를 검토한다. 창업기업의 ICO 참여의사를 분석하기 위해 기술수용모델(Technology Acceptance Model)을 이용하고, 연구모형을 구축하기 위해서는 기존 연구결과를 토대로 기업정보 공개, 사회적 영향, 성과기대에 대한 요소를 검토한다. This study analyzes the determinants of Initial Coin Offering(ICO) participation in start-up entrepreneurship. ICO is an application area using block chaining technology with explosive interest in crypto-currency. It attracts investors to an unspecified number of people through an online platform like crowd funding at the beginning stage of a startup company. Currently, there are some countries that prohibit ICO, such as Korea and China, while some countries actively attract and encourage ICO such as Switzerland and Singapore to foster new business areas. And find similarities by comparing the funding methods of entrepreneurs with crowd funding and IPO. This study reviews business classification of ICO participants, along with statistical data on ICO fundraising. The Technology Acceptance Model(TAM) is used to analyze the entrepreneurial intention of the ICO. In order to construct a research model, this study examines the elements of corporate information disclosure, social impact, and performance expectation based on existing research results.

북한강 수계에서 Dolichospermum의 유전생태학적 특성 연구

유미나 ( Yu Mi Na ),변정환 ( Byun Jeong-hwan ),백준수 ( Baek Jun Soo ),윤석제 ( Youn Seok Jea ),유순주 ( Yu Soon-ju ),변명섭 ( Byeon Myeong Seop ) 한국물환경학회(구 한국수질보전학회) 2019 한국물환경학회지 Vol.35 No.1

This study analyzed the occurrence pattern of Dolichospermum (= Anabaena) in the Bukhan river from March 2012 to December 2014 in order to identify the genotypes of Dolichospermum. Furthermore, 16S rRNA were analyzed to identify the genotypes of Dolichospermum that occurred in 2015 which were then compared to the reference sequence deposited at NCBI. During this period, the occurrence of Dolichospermum was highly correlated to water temperature. In the year 2012 and 2013, Dolichospermum appeared in Lake Cheongpyeong (CP), Sambong (SB), and Lake Paldang (P2) between July and August. However, in 2014, it appeared in SB and P2, but not in CP. This reduction in appearance was attributed to the decreased inflow to Lake Uiam as a result of low rainfall in 2014 as compared to 2012. In July 2015, the Dolichospermum 16S rRNA genotype was confirmed in five locations; Lake Cheongpyeong (CP), Seojong (SJ), Songchon Sewage Treatment Plant (SC), Joan (P4), and Lake Paldang (PD). Anabaena crassa of spiral clone, A. planctonica of linear clone, and A. circinalis of spiral clone exhibited high genetic similarity with the reference sequence. The 16r RNA genotype showed approximately 3 % sequence variation between the locations and were more similar to each other in locations that were closer.

都市民의 鍼治療에 대한 意識과 關聯要因分析

鄭鴻洙,卞廷煥,南喆論 韓國保健敎育學會 1992 보건교육건강증진학회지 Vol.9 No.1

This study carried out to investigate consciousness level and situation of treatment by acupuntury (the most important part of oriental medicine) and analyze factors affection to the praetice of exercise. The main purpose of the study was to five basic and necessery data in formulating a policy related to oriental Medical Treatment. The study was conducted by trained surveyers, for dueller in three cities (Seoul, Busan and Taegu) during 1990. 1. 4-1990. 1. 23. The result of this study can be summerized as follows. 1. The subject of criticism an investigation for general charactristic be conducted in seoul, Busan and Taegu city area an objective 417 person, 423 person, and 366 person was among those comparatively little more by male was higher rate than female. Those in classification age group evaluation was adopted b age group 10, 20 years old adult 41.3% of most higher rate, next rank was adopted by age group 40 years old(24.9%). 2. An objective of investigation survery was made to personnel were comparative an educated level significantly higher such as college graduated 48.8%, high school graduated 30.1%. And the native comes from urban area, rural, midium and small city rate were shown as 29.6%, 28.4% and 19.9% each other. There by classification of occupational job was shown by students has 27.4% are most higher significantly also there sales and servive field job appearanced 15.1% and expert technical job is 9.0%. Religion is buddist, Christianity, Catholicism all them each other shown 33.6%, 16.7% and 12.4%. An evaluation in economic situation value rate was appearanced by middle class is 61.7% and upper and lower classes are 14.4% and 23.9% with each other and married were 59.2%. 3. The people resident in cities area has experience of acupuncture were 70.4%. There by classification of an area was shown by Seoul, Busan and Taegu all them other shown 59.7%, 85.2%, 68.1%. According as sex was shown by male 71.7% was more higher than female. 4. The experience rate of acupuncture based on classification of married situation was showns married person (74.8%) was higher than single and unmarried. By evaluation in economic situation valve rate was appearanced by upper and lower classes are high, too. In religion valve rate was shown by catholicism was 80.0%, this religion was more higher than other religions. There by classification of occupation was shown by admin-clerk 77.8%, farmer-fisher 77.8%, sales services 76.2%, school staff 15.0%. 5. The reson of acupunctury treatment was shown Sprain 45.3%, Neuralgia 28.9%, Arthritis 8.4%, Hypertension 2.4%. As the case of sprain, 20 years old (57.0%) was the highest, 50, 60 years old has acupuntury treatment as neuralgia. In other side, by the classification of edacational level to evaluated be taken low for experience rate of acupuncture treatment for neuralgia, another for sprain was shown high. Native comes from urban was not shown higher than rural in experience rate of acupuncture due to neuralgai, but was shown higher due to arthritis and hypertension. Experience rate of acupuncture due to sprain lower income classes(52.0%), unmarried(59.6%), expert technician(65.0%), admin-clerk(50.0%), farmer-fishery(50.0%). Experience rate of acupuncture due to neuralgia come out high in upper classes (60.0%), married(57.1%), worker in factory(50.0%), school staff (55.6%). 6. As self-diagnosis of perfect cure rate come out 13.5% after acupuncture-treatment do good are 86.1% and be no good are 5.2%. In case of do good, Busan(96.2%) was shown higher than other region, male(88.8%) was shown higher than female. It was shown high in middle school (90.0%), laborer (100.0%), student (93.5%), expert technician (90.0%). As self-diagnosis of perfect cure rate after acupuncture-treatment male (15.4%) was shown higher than female, and 20, 30 years od (18.6% 23.3%) was shown higher than 40. 50 years old, and urban (16.3%), single (28.6%), upper classes (60.0%), laborer (33.3%), expert technician (25.0%), student (19.7%) come out high. 7. Unexperience of acupuncture that in future not be willing to treat by acupuncture are 12.1%, and be willing to treat by acupuncture are 44.4%. In time of not be willing to treat by acuaunture, female (16.7%) was shown higher than male. It come out Seoul(20.9%), 10years old (25.0%), middle school (18.8%), town (16.7%), lower class (17.6%). As occupation expert technician (27.3%), school staff (15.4%), worker in factory (14.3%) come out not be willing to treat by acupunctury. 8. The reason of not be willing to treat by acupuncture is because of fear (36.0%), be no good (14.2%), unscientific (10.7%). Due to fear not be willing to treat by acupuncture come out high as female (15.9%), 10, 20 years old (45∼49.0%). 9. The factor of effection of acupuncture treatment are religion (β=0.059), birthplace (β=0.060), occupation (β=0.188), Significance level is statistically presented as 1%, and explanation value are 12%.