Primary Productivity of Phytoplankton at the Eutrophic down Reach of a Regulated River(the Han River, Korea)

Namkung, Hyun,Gilson Hwang,Bomchul Kim,Kapsoo Kim 강원대학교 환경연구소 2001 環境硏究 Vol.18 No.-

A Study on Nonresponse Errors in the Internet Survey

Namkung, Pyong,Kim, Min Jung 한국통계학회 2002 Communications for statistical applications and me Vol.9 No.3

The advantage of internet survey compared to the traditional survey methods are speedy in data collection, cost-effective, high performed design and able to data process and analysis at the same time. The other side are difficult to select sample, come from serious nonresponse errors. We suggest the new internet survey method to the questionnaire design that have the high response rate, enough to advanced preparations and system stability.

A New Species of Cave Dwelling Grylloblattoidea (Grylloblattidae) from Korea

Namkung, Joon 한국곤충학회 1974 Korean journal of entomology Vol.4 No.1

원시무시곤충으로 주목되고 있는 Grylloblattoidea는 1914년 E.M. Walker가 최초로 발표한 이래, 북미각지에서 7종.2아종, 일본에서 5종, Siberia에서 1종이 기재된 바 있으나 우리나라에서는 아직껏 밝혀진 바가 없다. 저자는 1966년 6월 보한강상류인 정선군 비룡동굴에서 완전한 1성웅을 채집한 바 있어 여기에 Gallcisiana biryongensis(비룡갈르와 벌레)로 명명 기재한다. 본종은 다양색.무안.체장 34mm로 기지의 어느 것보다도 대형종이다. 대체적구조는 일본산 Galloisiana nipponensis에 닮으나 제10복배판 끝 Supra-anal plate가 둔만년필촉과 같이 무듸게 되며, 북미종과는 부절욕반이 있음에서 외관상으로도 분명히 구별된다. 본종의 중요 표징은 다음과 같다. (1) 두부는 편본하고 폭이 약간 넓은 원형으로 두개선이 명료하고, 복안은 퇴화되었으나 강대한 안부강모가 나있다. (2) 전흉배는 저대한 정방형, 중흉배는 전변이 좁은 제형, 후흉배는 전변이 약천 좁은 제형으로 각 측연과 중앙부에 불규칙한 강모가 나있다. (3) 복배판은 제4, 5절이 최대이며, 각 절의 하변에 8개, 측연에 1개씩의 강모가 정열하며 제10배판 끝은 순한 만년필촉 꼴로 일견 2분 된 듯한 감을 준다. (4) 미모는 9절로 되며, 각 말단부에 3,4재의 장강모가 나 있고, 미세 투명한 긴 감각모가 보인다. (5) 보각은 완장하며 부절욕반이 명료하다. (6) 웅생식기관은 복잡한 구조를 갖추며, 복지는 좌우비대칭으로 좌지는 폭광인 ?꼴이고, 우지는 장삼각형으로 기부끝에 투명한 단추꼴 돌기가 보인다. (7) 대형의 주름진 반전낭이 우음경엽부에서 돌출하고 있으며, 비교적 완장한 주음경과 부음경이 보인다.

Prediction of coal fouling using an alternative index under the gasification condition

Namkung, H.,Xu, L.H.,Kang, T.J.,Kim, D.S.,Kwon, H.B.,Kim, H.T. Applied Science Publishers 2013 APPLIED ENERGY Vol.102 No.-

Coal gasification was carried out in order to verify the coal fouling tendency in the drop tube furnace (DTF), which can simulate an entrained-bed gasifier. Thirteen pulverized coal samples, in the range of bituminous and sub-bituminous, were utilized, and compared, with predictions using a wide range of empirical indices. Large discrepancies were noted in most cases, with respect to experimental results, ash deposition rates, and different indices. Some indices used for anticipating fouling tendency are not co-related with the results of this experiment. A newly approached index, which is especially important considering the diffusivity parameter, looks at the ratio of acid and alkali mineral matters injected into gasifier and heat flux, indicates that traditional expressions are modified to account for other parameters which influence the ash deposition phenomenon. The alternative index resulted in improved correlations between predictions and experimental observations.

Multilateral approaches for investigation of particle stickiness of coal ash at low temperature fouling conditions

Namkung, Hueon,Kim, Hyung-Taek,Wang, Fuchen,Lin, Kuangfei,Yu, Guangsuo Springer-Verlag 2017 Korean Journal of Chemical Engineering Vol.34 No.12

<P>Particle stickiness is a key parameter for increasing ash deposition in gasification process. We conducted multilateral investigations to evaluate particle stickiness of coal ash at low temperature fouling conditions through Watt and Fereday's viscosity model, dilatometry (DIL) and laser flash apparatus (LFA) technique. Seventeen coals were employed for ash deposition experiments under gasification condition through drop tube furnace (DTF). The low viscosity not only led to increasing ash deposition behavior, but also increasing the particle size of deposited ash. From DIL analysis, the ash sintering behavior increased with increasing temperature due to increase of particle stickiness. The high amount of Fe2O3, CaO and MgO components resulted in low sintering temperature and high reduction of physical length. Through LFA analysis, the thermal conductivity increased with increasing temperature, because of increasing particle stickiness. In addition, its value was correlated with the propensity of common fouling indices.</P>

Identification of gene-gene interactions in the presence of missing data using the multifactor dimensionality reduction method

Namkung, Junghyun,Elston, Robert C.,Yang, Jun-Mo,Park, Taesung Wiley Subscription Services, Inc., A Wiley Company 2009 Genetic epidemiology Vol.33 No.7

<P>Gene-gene interaction is believed to play an important role in understanding complex traits. Multifactor dimensionality reduction (MDR) was proposed by Ritchie et al. [2001. Am J Hum Genet 69:138–147] to identify multiple loci that simultaneously affect disease susceptibility. Although the MDR method has been widely used to detect gene-gene interactions, few studies have been reported on MDR analysis when there are missing data. Currently, there are four approaches available in MDR analysis to handle missing data. The first approach uses only complete observations that have no missing data, which can cause a severe loss of data. The second approach is to treat missing values as an additional genotype category, but interpretation of the results may then be not clear and the conclusions may be misleading. Furthermore, it performs poorly when the missing rates are unbalanced between the case and control groups. The third approach is a simple imputation method that imputes missing genotypes as the most frequent genotype, which may also produce biased results. The fourth approach, Available, uses all data available for the given loci to increase power. In any real data analysis, it is not clear which MDR approach one should use when there are missing data. In this article, we consider a new EM Impute approach to handle missing data more appropriately. Through simulation studies, we compared the performance of the proposed EM Impute approach with the current approaches. Our results showed that Available and EM Impute approaches perform better than the three other current approaches in terms of power and precision. Genet. Epidemiol. 33:646–656, 2009. © 2009 Wiley-Liss, Inc.</P>

A New Species of Galloisiana (Grylloblattidae) from Kosudong-gul Cave in Korea

Namkung, Joon 한국곤충학회 1974 Korean journal of entomology Vol.4 No.2

한국의 동굴에서 Galloisiana가 종종 발견되지만 그 성숙한 자웅을 얻기는 힘든다. 저자는 1973年 겨울 남한강상류인 충북 단양군 고수동굴에서 성숙한 1♂, 1♀을 얻었다. 이는 지난번 발표한 Galloisiana biryongensis 전혀 다른 신종으로 밝혀졌으므로 이에 기재발표한다. 본종의 중요표징은 다음과 같다. (1) 몸길이 약 22mm의 중형종으로 뚜렷한 겹눈을 가지며 더듬이는 46-47마디이고, 그 셋째마디는 둘째마디의 약 3배의 길이이다. (3) 앞가슴판의 목피부판(The first cervical sclerite) 윗쪽 가에 4재적의 센털이 정열한다. (3) ♂의 제10배등판끝인 Supra-annal plate는 좌측이 일그러진 삼각형 꼴로 그 끝이 순하고 안쪽으로 굽어 있다. (4) 수생식기관의 바른쪽 원밑마디 (coxopodite)의 밑부끝에 투명한 단추꼴 돌기가 있으나 숨겨져 있어 외관상 잘 보이지 않는다. (5) 반전상 (Eveersible sac)은 작으며 음경의 양 모퉁이가 뿔꼴로 돌출하고 옆에는 갈구리꼴의 가시돌기가 있다. (6) 산란관의 상란관 끝은 미모의 제4마디의 $\frac{3}{4}$에 이르며, 그 밑부로부터 2/15 되는곳에 중란관의 밑부가 있다.

Who Buys Our Brand? The Influence of Consumption Values and the Congruity with Brand Benefits on Brand Identification, Trust and Loyalty

Namkung, Sol,Park, Seong-Yeon Korean Marketing Association 2021 ASIA MARKETING JOURNAL Vol.22 No.4

This paper explores how the positive effect achieved when consumption value matches brand benefit can increase brand loyalty. Prior research on consumption value mainly focused on perceived value; these studies omit consumers' views of consumption value. Therefore, this study examines the effect of congruence between consumption values (functional, emotional, social, and ethical value) and perceived brand benefits (enabling, enticing, symbolic, and socially responsible benefits) on consumers' brand identification, trust, and loyalty. We find a positive effect on brand identification and brand trust when a consumer's value is similar to a brand benefit, particularly between functional value and enabling benefit, and ethical value and socially responsible benefit. However, congruence between consumption value and perceived brand benefit only had an indirect effect on brand loyalty by mediating brand identification and trust. This study provides a basis for implementing a marketing strategy to build brand assets and increase brand loyalty by providing consumers with the value they want in a diversified market.

Regulation of Systemic Energy Homeostasis by Peripheral Serotonin

Namkung, Jun,Oh, Chang-Myung,Park, Sangkyu,Kim, Hail Association for Research of MPS and Rare Diseases 2016 Journal of mucopolysaccharidosis and rare disease Vol.2 No.2

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. Serotonin is among those traditional pharmacological targets for anti-obesity treatment because central 5-HT functions as an anorexigenic neurotransmitter in the brain. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Fat specific Tph1 knock-out (Tph1 FKO) mice exhibit similar phenotypes as mice with pharmacological inhibition of 5-HT synthesis, suggesting the localized effects of 5-HT in adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure in BAT and Htr2a KO mice exhibit the decreased lipid accumulation in WAT. These data suggest the clinical significance of the peripheral serotonergic system as a new therapeutic target for anti-obesity treatment.

Allocation in Multi-way Stratification by Linear Programing

NamKung, Pyong,Choi, Jae-Hyuk 한국통계학회 2006 Communications for statistical applications and me Vol.13 No.2

Winkler (1990, 2001), Sitter and Skinner (1994), Wilson and Sitter (2002) present a method which applies linear programing to designing surveys with multi-way stratification, primarily in situation where the desired sample size is less than or only slightly larger than the total number of stratification cells. A comparison is made with existing methods both by illustrating the sampling schemes generated for specific examples, by evaluating sample mean, variance estimation, and mean squared errors, and by simulating sample mean for all methods. The computations required can, however, increase rapidly as the number of cells in the multi-way classification increase. In this article their approach is applied to multi-way stratification using real data.