Effects of Key Drivers on Continuing to Use Digital Convergence Services: Hierarchical Component Approach

정석인,한억수,한현수 한국전자통신연구원 2014 ETRI Journal Vol.36 No.6

Technological advances made with the development ofdigital technology and the Internet have led to theemergence and evolution of digital convergence — theintegration of media and communications. This, in turn,has led to the creation of the representative broadcastand communication convergence business model (IPTVservice). This study examines the consumption patternsand behaviors of IPTV service customers and explores theprocess of their continuous use of the IPTV service,thereby endeavoring to contribute to the diffusion ofdigital convergence services. To survey customers’continuous use of the IPTV service, this study first designsa research framework based on an examination of theexisting literature on satisfaction, loyalty, and so on. Inaddition, research is conducted on the switching barrier ofthe method of consolidating customers’ adherence to agiven IPTV service by increasing the burden on them,thereby developing a final research model with which toattempt yet another heterogeneous approach. This enablesnot only an analysis of the causal relationship withantecedent variables but also a measurement of theexplanatory contribution of the antecedent variables’ subvariables.

질산태 질소 정량을 위한 환원 증류법에서 Devarda’s Alloy의 입자크기 및 함량이 미치는 영향

정석호(Seok Ho Jung),권현재(Hyun Jae Kwon),정덕영(Doug Young Chung),한광현(Gwang Hyun Han) 韓國土壤肥料學會 2011 한국토양비료학회지 Vol.44 No.3

We analyzed the particle size distributions of three commercially available Devarda’s alloy (DA) products, tested the nitrate recoveries of each particle size category, and examined the amounts of DA required for 100% recovery by varying NO3−N concentration from 0.5 to 10 mg. We observed that use of DA coarser than 200 mesh resulted in poor analytical recovery (< 80%). While the tested alloys were considered to be fine enough (>90% of the particles were less than 100 mesh), the recovery dramatically declined from 80% to 10% in a high concentration range (4 to 10 mg N). Satisfactory recovery was obtained by increasing the amount of finer DA (less than 300 or 450 mesh). However, there was no quantitative relationship between the amount of fine DA and nitrate recovered. Generally, the amount of nitrate reduced per unit DA decreased as the recovery efficiency declined. These results suggest that a sufficient amount of DA must be determined based on particle size distribution, and that treatment of at least two levels of DA and comparison of the subsequent change in nitrate recovery is required for soils containing high levels of nitrate. In addition, further studies are encouraged to account for the observed stoichiometric dis-equivalence of recovered nitrate N per unit mass of DA.

MPEG을 이용한 실시간 이동 물체 추적 시스템

정석재(Seok-Jae Jeong),김민구(Min-Koo Kim),김동윤(Dong-Yoon Kim) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.25 No.1B

이동 물체를 실시간으로 추적하는 시스템의 구현은 영상처리의 복잡성으로 매우 어렵다는 문제점을 가지고 있다. 물체 추적 방법 중 블록 기반 방법은 움직임 정보를 블록 단위로 계산하여 물체의 이동을 추적하는 방법으로 움직임 정보인 움직임 벡터를 구하는 시간이 많이 걸린다. 이러한 계산상의 문제는 블록 기반 방법을 압축기법으로 사용한 MPEG이나 H.261과 같은 표준 동영상 스트림을 직접 접근함으로써 해결될 수 있다. 그러나, 이렇게 직접 얻어진 움직임 벡터들은 조명이나 하드웨어적인 특성 때문에 원치 않은 노이즈를 가지게 된다. 본 논문에서는 이러한 노이즈를 제거하기 위해 이미지 필터링에 많이 사용되는 중간값(median) 연산자를 사용하는 방법을 제안하였다. 이 방법은 움직임 벡터의 필터링에 대해서 잘 동작함을 보였다.

호기순환 호흡계를 이용한 토양처리 석탄바닥재의 유기물 분해에 미치는 영향

정석호(Seok-Ho Jung),정덕영(Doug-Young Chung),한광현(Gwang-Hyun Han) 한국토양비료학회 2012 한국토양비료학회지 Vol.45 No.2

석탄 연소 부산물인 비산회 (fly ash)는 이산화탄소 발생을 저감하고 토양 탄소를 격리하는 효과가 있음이 보고된바 있다. 같은 연소 부산물인 석탄바닥재 (bottom ash)는 비 산회와 유사한 화학적 성질을 가지고 있고, 아울러 다공성으로 토양미생물들이 정착하는 적절한 담체로서의 기능을 가지고 있다. 이에 본 연구는 성질이 다른 유기물들 (헤어리베치, 청보리, 유박비료)이 처리된 토양에서 석탄바닥재가 토양 미생물들에 의한 유기물 분해 및 호흡량에 미치는 영향을 조사하였다. 미생물에 의한 유기물의 분해속도는 유박비료, 헤어리베치, 청보리의 순으로 높게 나타났고, 유기물과 석탄바닥재를 함께 처리하였을 때, 유의하게 감소하였다. 이산화탄소 발생량의 경시적인 변화는 유기물의 이분해성에 의존하였으나, 석탄바닥재를 처리하였을 때 유의하게 발생량이 감소하였다. 총 누적 이산화탄소 발생량 또한 이와 유사한 결과를 보였다. 석탄바닥재가 함유하고 있는 중금속 등과 같은 유해물질의 농도가 높지 않다면, 본 연구의 결과들은 석탄바닥재가 토양 처리 유기물의 이산화탄소 발생 저감 및 토양 탄소격리에 긍정적으로 기여 할 수 있는 소재로서 가능성이 있음을 보여준다. Disposal of high amount of coal combustion by-products, such as fly ash and bottom ash, is of a great concern to the country, due to the huge treatment cost and land requirement. On the other hand, those coal-ash wastes are considered to have desirable characteristics that may improve physical, chemical, and biological properties of soils. Especially, compared with fly ash, bottom ash has a larger particle size, porous surface area, and usable amount of micronutrients. In the present study, we examined bottom as a soil amendment for mitigating CO₂ emission and enhancing carbon sequestration in soils fertilized with organic matter (hairy vetch, green barely, and oil cake fertilizer). Through laboratory incubation, CO₂ released from the soil was quantitatively and periodically monitored with an enforced-aeration and high-temperature respirometer. We observed that amendment of bottom ash led to a marked reduction in CO₂ emission rate and cumulative amount of CO₂ released, which was generally proportional to the amount of bottom ash applied. We also found that the temporal patterns of CO₂ emission and C sequestration effects were partially dependent on the relative of proportion labile carbon and C/N ratio of the organic matter. Our results strongly suggest that amendment of bottom ash has potential benefits for fixing labile carbon as more stable soil organic matter, unless the bottom ash contains toxic levels of heavy metals or other contaminants.

Sulfoxide based Branch-Controlled SARA ATRP

정석현,김동우,조홍열,백현종 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

Separation of soil Organic Debris using Sucrose-ZnCl2 Density Gradient Centrifugation

정석호,정덕영,한광현 한국토양비료학회 2012 한국토양비료학회지 Vol.45 No.1

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris (< 1.5 g cm-3),light fraction (1.5-2.0 g cm-3), and heavy fraction (> 2.0 g cm-3), based on high density ZnCl2- sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the ZnCl2- sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to 2.0 g cm-3. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

Effects of Integrated Soil Amelioration Techniques to Mature Newly Established Research Fields

정석재,현병근,손연규,조현준,최정원,이평호,임동혁 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.2

The Rural Development Administration moved to Jeonju for the balanced development of the land. This situation required establishment of new research fields with soils appropriate to cultivation. We applied a variety of amelioration techniques to mature soils of new research fields of the National Institute of Agricultural Science (NAS) and evaluated effects of the integrated amelioration techniques. The schedule of amelioration was following: 1) location of research fields was determined, 2) surface and subsoil samples were collected separately, 3) after aligning the top level of research fields, subsoil and surface soil were re-established with soil amendment, 4) the green manure crops were grown four seasons to improve the uniformity and increase the organic content of the research field, and 5) drainage canal and/or underdrainage were applied to poorly drained fields. The last green manure crop was rape in RDA fields and green barley in NAS fields. The average height, fresh weight, and dry matter weight of rape in good condition were 123 cm, 3,938 kg 10a-1, and 651 kg 10a-1, respectively. The height, fresh weight, and dry matter of green barley, on average, were 97 cm, 3,013 kg 10a-1, and 1,004 kg 10a-1, respectively. In the chemical properties of paddy field, pH and levels of silicate, calcium, magnesium, and potassium were in appropriate range but organic matter content of 16 g kg-1 was less than the optimum level. In the chemical properties of upland field, pH and levels of phosphorus, calcium, magnesium, and potassium were appropriate range but organic matter content of 12 g kg-1 was less than the optimum range. Evaluation of well-adapted soil was performed. The field in RDA was classified into the superior class with points ranging from 90 to 95 by the field evaluation test. The fields in NAS were mainly evaluated as the superior class with points greater than 85. However, some fields in NAS remained low quality with scores between 80 and 83. Further soil amelioration practices were suggested to fields with low soil quality.

발해 마을유적 소고

정석배(JUNG Suk-bae) 고구려발해학회 2013 고구려발해연구 Vol.47 No.-

방어시설이 없는 일반 마을유적은 평민들의 삶을 가장 잘 보여주는 유적이다. 발해의 일반 마을유적은 중국의 길림성과 흑룡강성 그리고 러시아 연해주 일대에 현재 약 319개소가 알려져 있다. 이 글에서는 발굴조사 혹은 수습조사를 통해 유구의 내용이 알려져 있는 19개 발해 마을유적에 대해 다양한 측면에서 검토해 보았다. 유적은 절대 다수가 크고 작은 강가의 평지에 입지하는데 이는 발해 평민들의 생업과 깊은 관련이 있는 것으로 생각된다. 마을유적에서는 잡곡류, 콩류, 공예 농작물 등의 탄화곡물, 말, 소, 개, 돼지 등의 가축 뼈와 들짐승의 뼈, 물고기의 뼈, 담수와 해수의 조개껍질 등이 출토되었다. 이 사실은 발해 평민들이 농사와 가축사육에 뿐만 아니라 경우에 따라서는 사냥과 어로, 담수 연체동물의 채집에도 종사하였음을 말한다. 이에 대해서는 농기구, 어구, 사냥도구 등의 유물들도 뒷받침한다. 해수 조개껍질은 바다에서 멀리 떨어진 지역에까지 해산물이 공급되었음을 말한다. ‘산삼파개’는 산삼을 판 심마니도 존재하였음을, 술 저장 토기는 평민들이 술도 빚어 마셨음을 말해 준다. 마을유적에서는 발해 평면들의 의복과 장식과 관련된 유물들도 출토된다. 마을유적은 면적에 따라 소형(5천~2만5천㎡), 중형(5만~15만㎡), 대형(28만~30만㎡)으로 구분된다. 대형유적은 진흥유적과 꼰스딴찌노브까 1유적 두 곳이다. 진흥유적은 목단강을 따라 나있던 ‘흑수말갈도’에, 꼰스딴찌노브까 1유적은 ‘솔빈도’에 각각 위치하고 있기 때문에 이 두 유적은 발해의 지방교통로에서 가장 중심적인 역할을 하였던 마을유적이라고 추정해볼 수 있다. 발해 솔빈부가 있던 수분하-라즈돌나야 강 주변에는 연해주 지역에만 135개의 발해유적이 알려져 있어 이 유적들을 서로 이어주던 그리고 발해의 중심지와 연해주 남부지역을 서로 이어주던 교통로의 존재를 상정해 볼 수 있다. 이 교통로는 ‘솔빈도’라 부르는 것이 가장 타당할 것이다. 대부분의 마을유적에서 발견되고 있는 구들의 존재는 발해시기에 구들이 이미 일반 평민들에게까지 대중화되었음을 보여준다. 또한 마을유적에서 출토된 유물과 유구들은 발해의 평면들이 마을 내에서 가죽 가공, 제철 작업, 금속가공 작업, 토기 생산, 토제품 생산, 기와 생산 등과 같은 수공업 생산에도 종사하였을 보여 준다. 도로유구와 차관을 통해 볼 때에 마을에는 길이 나있었고 그 길을 따라 짐을 실은 수레가 다녔음도 알 수 있다. 신앙생활과 관련하여 마을유적에서 발견되는 토제 기마인물상은 발해 평민들 사이에 샤머니즘이 존재하였음을 보여 주며, 또한 마을유적 가까이에 사찰유적이 존재하는 것은 평민들 사이에도 불교가 어느 정도 보급되었음을 말한다. 마지막으로 문화층의 상태가 알려져 있는 유적들 중 56%가 발해 때에 새로이 개척된 것으로 파악되었는데 이는 발해시기에의 급증한 인구증가 및 식량 확보를 위한 새로운 땅의 개간활동이 매우 활발하였음을 반증한다. 또한 발해 때에 새로이 개척된 연해주 지역의 마을유적들에 모두 구들을 사용하였다는 것은 그 주민들의 구성에 고구려계가 적지 않았음을 증명할 것이다. Settlements without protective structures may best show the leif of ordinary people. There are totally about 319 settlements of Balhae in the territory of Heilongjiang and Jilin provinces of China and Primorye region of Russia. In this work 19 settlements in which the objects are known through excavation or rescue operations are studied from different points of view. Balhae settlements in the vast majority of cases are located nearby large rivers and their tributaries, that is associated with life activities of their inhabitants. In settlements the charred grain crops, such as cereals, legumes and industrial crops, bones of domestic animals such as horses, cattle, dogs, pigs, wild animal bones, fish bones, shells of freshwater and marine mollusks are discovered. This fact suggests that the common people in Balhae engaged not only in farming and cattle breeding, but also in hunting, fishing and gathering shellfish. This is confirmed by agricultural implements, tools for fishing and hunting. Sea shells of marine mollusks indicate marine products were supplied in areas far from the sea. “Sansam poking-stick” says that “simmani” that is a collector of sansam(mountain ginseng) existed in Balhae period, and ceramic vessels with the remnants of alcohol show that ordinary people cooked ardent drinks and drank them. In settlements artifacts related to garment pieces and onraments are also found. The settlements are divided into small (5.000-25.000㎡), medium (50.000-150.000㎡) and large (280.000-300.000㎡). Large settlements are represented by two ones: Zhenxing and Konstantinovka 1. The first one is located in the area of “road Heuksu Malgal”, the second one near the “road Solbin” so we can say that these were two settlements which played the biggest role at the provincial roads in Balhae. The territory of the Suifen-Razdolnaya rivers-basin only in Primorye region contains 135 Balhae sites, so we can assume that there was a road that connected these sites to each other and the center of Balhae with the southern part of Primorye. It will be correct to call this road “Solbindo”, that is, “Solbin road”. The presence of kangs (gudyl) in most of the settlements shows that in Balhae time gudyl has already been distributed among ordinary people. In addition, the findings and the objects studied in the settlements say that their inhabitants were engaged in handicrafts such as leather processing, production of iron, treatment of metal parts, production of pottery and tiles. As judged by the roads and wheel hubs, we can assume that in the settlements there were roads, where wentcarts. As to the beliefs of ordinary people, clay horsemen from the settlements indicate the existence of shamanism; in addition, the presence of Buddhist temples in the vicinity of settlements suggests that Buddhism was to a certain degree diffused among ordinary people of Balhae. Finally, among the settlements in which cultural layers could be defined, 56% are exploited for the first time in Balhae period. This fact indicates that in Palhae period the population increased and new land for food production was actively exploited. In addition, the fact that in all the settlements in Primorye, first exploited in Balhae period gudyl were built, would indicate that among the inhabitnats were many people of Koguryo origin.

수리실험을 통한 보 연결부 제방 세굴 특성 분석

정석일,이승오,Jeong, Seok Il,Lee, Seung Oh 한국안전학회 2017 한국안전학회지 Vol.32 No.4

Typical flow regime of overflow at barrier or weir constructed in mid and small streams becomes as the submerged flow during most flood events. One of major causes of barrier failure has been reported as the levee-scour near the conjuction node between barrier and levee. However, most related design guidelines in Korea have not mentioned about the protection of levee around barrier or weir in detail. Furthermore, most previous researches have focused on the flow characteristics of overflow around several types of weirs but they did not have considered the material properties of levee itself. In this study, local scour near barrier was investigated with different material properties of levee under the submerged overflow condition which is assumed to reenact a flood event. Based on results from Fritz et al. and Mavis et al., a theoretical formula was also proposed in initial stage of laboratory experiments. And hydraulic experiments were carried out for the verification of the proposed formula. Levee was installed in the prismetic trapezoidal open channel and most parts were made of concrete except for movable section in which scour was expected to occur for the efficiency of experimental procedure. Each compaction of movable section in levee was followed by the basis of the KS F 2312. Further, after performing the experiments to find the optimum water content for each sediment, the specific amount of water was injected before flowing water. The difference between the proposed theoretical formula and experiment results was not much but considerable, which might be caused by the effect of compaction. For theoretical approach, it seemed that the formula did not take into account the compaction of levee, thus the correction coefficient for levee compaction determined in the literature was considered. Finally, the formula for the length of scour around barrier or weir was proposed, which can be useful to predict a levee in the reference design of revetment in mid and small streams. As shortly future study, scour length of levee around barrier or weir under different flow conditions such as perfect overflow condition will be studied and it will be able to contribute to suggest the design formula or criteria under all overflow conditions near barrier or weir.

나선형 패턴 반사면에 대한 가공 특성 연구

정석경(S. K. Jeong),여우종(W. J. Yeo),전민우(M. W. Jeon),최환진(H. J. Choi),김이종(I. J. Kim),김건희(G. H. Kim),이원균(W. K. Lee) 한국기계가공학회 2021 한국기계가공학회 춘추계학술대회 논문집 Vol.2021 No.12