Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

Changes of Landscape Structure for the Recent 20 Years in the Wangsuk Stream Basin of the Central Korea

Lee, Chang-Seok,Cho, Yong-Chan,Shin, Hyun-Chul,Lee, Seon-Mi The Ecological Society of Korea 2006 Journal of Ecology and Environment Vol.29 No.4

Landscape changes for 20 years between 1981 and 2001 in the Wangsuk stream basin located on the central Korea were investigated on the basis of physiognomic vegetation map made from the aerial photograph interpretation and field check. Changes of landscape structure were noticeable in agricultural field and forest landscape elements. Changes in the agricultural fields due to transformation of agricultural pattern into the institutional agriculture dominated landscape change, although urbanization also contributed to such change. The former change due to change of food production structure originated from socio-economic development during this period and the latter to the overpopulation of Seoul. As energy sources for heating and cooking, fertilizer, and fodder for livestock transform from plant materials to fossil fuel, manufactured one, and grain, succession of forest escaped from direct human disturbance dominated change of landscape structure in forested land. Differently from the positive landscape change in the upper area, change in the lower area deteriorated landscape quality by increasing artificial land. It was estimated that such landscape deterioration in the Wangsuk stream basin would influence water quality of the stream. In order to realize sustainable land-use against such environmental degradation, systematic environmental management based on landscape ecological perspective such as "an eco-plan for creating riparian vegetation belt," which is under preparation by Ministry of Environment, was recommended.

Can an Education Program alter Students' Perceptions of the Causes of and Solutions to Climate Change? - A Case in South Korea

Jang, Yong-chang The Korean Environmental Sciences Society 2022 한국환경과학회지 Vol.31 No.10

This study investigated whether an educational program could alter students' perceptions of the causes of and solutions to climate change. On October 23, 2020, a 3-hour climate change educational program was provided to 400 high school students in Suncheon City, (Jeonnam Province, South Korea). According to the program, climate change represents a social dilemma, or tragedy of the commons; it also asserts that collective action aimed at strengthening government policy is the optimal solution to climate change, and concludes that motivated citizens should convey their opinions directly to the government through political action. After the program, the students made and shared placards calling for policy-based responses to climate change. Questionnaires completed by the students before and after the program revealed that their perceptions of the causes of and solutions to climate change changed significantly. This case study indicates that education programs have the potential to alter students' perspectives and promote actions aimed at mitigating and adapting to climate change.

Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>

노인운동의 변화단계에 따른 의사결정 균형에 대한 연구

김소인,전영자,박은숙,김순용,장성옥,이평숙,이숙자 성인간호학회 2000 성인간호학회지 Vol.12 No.1

Purpose : This study was carried out to identify the factor of decisional balance for exercise. This was composed of a set of variables at the level of decision making when the elderly decide to do exercise. It was used to classify and identify the characteristics of the stages of change for exercise to which the elderly belong, and was used to identify the variables of decisional balance which influence the stage of change for exercise in the elderly. Methods : Convenient samples of 198 subjects over age 60 in Seoul(mean age=70) were selected from community living, mentally competent older adults and the data was collected from April 1, 1999 to May 31, 1999. The research instrument was the Decisional Balance Measure for Exercise(Marcus & Owen., 1992), Stage of Change Measure(Marcus et al, 1992). The data was analyzed by SAS Program. Results: 1. According to stage of change measure, without missing data, 191 subjects were distributed in each stage of change for exercise : 50 subjects(26.1%), 7 subjects(3.6%), 52 subjects(27.2%), 4 subjects(2%), and 78 subjects(40.8%) belonged to the pre-contemplation stage, contemplation stage, preparation stage, action stage and maintenance stage. 2. Factor analysis identified 3 factors of decisional balance as appropriate factors for excise of the elderly and named by researchers; 1)'Perceived Physical-psychological benefit', 2)'Perceived Physical-psychological burden', and 3)'Perceived time burden'. 3. The analysis of variance showed that the two components Perceived Physical - psychological benefit(F=45.95, p=.0001), and Perceived Physical-psychological burden(F=26.52, P=.001) were significantly associated with stage of change. 4. Through the discriminant analysis, it was found that both 'Self Perceived Physical-Psychological benefit' and 'Perceived Physical-Psychological burden' were the influential variables in discriminating the three stages of change(pre-contemplation, preparation, and maintenance). Conclusion: Results are consistent with the application of the Transtheoretical model, which has been used to understand how people change health behaviors. Even though this study is a cross-sectional, not a longitudinal study, the findings of this study give useful information for exercise intervention about especially the factors relating to decision making for exercise of the elderly in the different stages of change of exercise.

Changes in the Ångstrom Exponent during Aerosol Coagulation and Condensation

Jung, Chang H.,Lee, Ji Yi,Kim, Yong P. Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the ${\AA}$ngstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed, and a sensitivity analysis of the ${\AA}$ngstrom exponent with regards the coagulation and condensation process was performed. The ${\AA}$ngstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the ${\AA}$ngstrom exponent during coagulation and condensation, different real and imaginary parts of the refractive index were considered. The results show that the ${\AA}$ngstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the ${\AA}$ngstrom exponent. The degree of change in the ${\AA}$ngstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the ${\AA}$ngstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the ${\AA}$ngstrom exponent as well as the chemical composition. Subsequently, this study shows how the ${\AA}$ngstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Changes in the Angstrom Exponent during Aerosol Coagulation and Condensation

Chang H. Jung,Ji Yi Lee,Yong P. Kim,김용표 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the Ångstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed,and a sensitivity analysis of the Ångstrom exponent with regards the coagulation and condensation process was performed. The Ångstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the Ångstrom exponent during coagulation and condensation,different real and imaginary parts of the refractive index were considered. The results show that the Ångstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the Ångstrom exponent. The degree of change in the Ångstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the Ångstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the Ångstrom exponent as well as the chemical composition. Subsequently, this study shows how the Ångstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Changes in Spatiotemporal Parameters and Lower Limb Coordination During Prosthetic Gait Training in Unilateral Transfemoral Amputees

Yunhee Chang,Chang-Yong Ko,Bo Ra Jeong,Jung Sun Kang,Hyuk-Jae Choi,Gyoosuk Kim,Hyunjun Shin,Sehoon Park 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.3

When applying prosthetic gait training to patients with lower limb amputation, monitoring the gait change process is crucial for establishing and modifying rehabilitation training plans. In addition, since human gait involves complex movement of several joints, it is necessary to analyze the organic movement of adjacent joints rather than a single joint in the lower extremities for understanding the process of gait change. Therefore, this study aimed to analyze changes in spatiotemporal parameters and lower limb coordination during prosthetic gait training in unilateral transfemoral amputees (TFAs). This retrospective case–control study included 10 unilateral TFAs and 10 healthy individuals as controls. TFAs received prosthetic gait training for 12 weeks and gait changes were analyzed every 2 weeks using a 3D motion analysis system. The measured variables were spatiotemporal parameters and the continuous relative phase between hip and knee joints. The highest improvement in walking speed was seen at week 4 of training, and the continuous relative phase was most symmetric at week 8. The lower limb coordination pattern was more in-phase in the TFAs than in the controls, and the coordination variability was also lower for the TFAs than for the controls. In addition, the rate of change in lower limb coordination of TFAs was lower than that of spatiotemporal parameters and was significantly different from that of the controls even after training. Considering that the decrease in lower limb coordination is related to gait efficiency, balance, and risk of fall, there is a need to develop therapeutic strategies that can further improve the coordination of TFAs.

Correlation between skeletal and dental changes after mandibular setback surgery-first orthodontic treatment

Chang-Hoon Rhee,Youn-Kyung Choi,Yong-Il Kim,Seong-Sik Kim,Soo-Byung Park,Woo-Sung Son 대한치과교정학회 2015 대한치과교정학회지 Vol.45 No.2

Objective: To investigate skeletal and dental changes after application of a mandibular setback surgery-first orthodontic treatment approach in cases of skeletal Class III malocclusion. Methods: A retrospective study of 34 patients (23 men, 11 women; mean age, 26.2 ± 6.6 years) with skeletal Class III deformities, who underwent surgery-first orthodontic treatment, was conducted. Skeletal landmarks in the maxilla and mandible at three time points, pre-treatment (T0), immediate-postoperative (T1), and post-treatment (T2), were analyzed using cone-beam computed tomography (CBCT)-generated half-cephalograms. Results: The significant T0 to T1 mandibular changes occurred ?9.24 ± 3.97 mm horizontally. From T1 to T2, the mandible tended to move forward 1.22 ± 2.02 mm, while the condylar position (Cd to Po-perpendicular plane) shifted backward, and the coronoid process (Cp to FH plane) moved vertically. Between T1 and T2, the vertical dimension changed significantly (p < 0.05). Changes in the vertical dimension were significantly correlated to T1 to T2 changes in the Cd to Po-perpendicular plane (r = ?0.671, p = 0.034), and in the Cp to FH plane (r = 0.733, p = 0.016), as well as to T0 to T1 changes in the Cp to Poperpendicular plane (r = 0.758, p = 0.011). Conclusions: Greater alterations in the vertical dimension caused larger post-treatment (T2) stage skeletal changes. Studying the mandibular position in relation to the post-surgical vertical dimension emphasized the integral importance of vertical dimension control and proximal segment management to the success of surgery-first orthodontic treatment.

단파장 자외선(254nm)에 노출된 고밀도 폴리에틸렌 수지의 카르보닐 지수(CI)와 기계적 물성 변화의 관계에 관한 연구

김창환 ( Chang Hwan Kim ),신진용 ( Jin Yong Shin ) 한국공업화학회 2013 공업화학 Vol.24 No.2

This paper studied the possibility to predict a mechanical property variation from changes in created carbonyl bands by irradiating the surface of high-density polyethylene with short-wavelength ultraviolet radiation of 254nm to induce a fast chemical degradation. The meaning of this study lies in checking whether a mechanical property change with the same chemical property as the induced optical deterioration is caused by using a UVC lamp with high photon energy instead of optical deterioration via xenon arc light source and outdoor exposure test via natural sunlight requiring a long time. The mechanical strength of high-density polyethylene checked by a tensile test and a creep destruction test showed a similar tendency with CI changes. In particular, the yield strength and elongation had a close relationship with the exposure time to ultraviolet radiation. Accordingly, this paper presented a method to grasp the mechanical property change outdoors requiring a long time more fast through the relationship between the mechanical property change and the carbonyl index using a UVC lamp causing the fast surface degradation.